WO2016059691A1 - Production method for purified daily life water and production apparatus for purified daily life water - Google Patents

Production method for purified daily life water and production apparatus for purified daily life water Download PDF

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Publication number
WO2016059691A1
WO2016059691A1 PCT/JP2014/077499 JP2014077499W WO2016059691A1 WO 2016059691 A1 WO2016059691 A1 WO 2016059691A1 JP 2014077499 W JP2014077499 W JP 2014077499W WO 2016059691 A1 WO2016059691 A1 WO 2016059691A1
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Prior art keywords
water
membrane
raw water
nucleating agent
raw
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PCT/JP2014/077499
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French (fr)
Japanese (ja)
Inventor
丸木祐治
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株式会社タカギ
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Priority to PCT/JP2014/077499 priority Critical patent/WO2016059691A1/en
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D21/00Separation of suspended solid particles from liquids by sedimentation
    • B01D21/01Separation of suspended solid particles from liquids by sedimentation using flocculating agents
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D61/00Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/14Ultrafiltration; Microfiltration
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D61/00Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/14Ultrafiltration; Microfiltration
    • B01D61/16Feed pretreatment
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/44Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/52Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities

Definitions

  • the present invention relates to water treatment technology.
  • Patent Document 1 a filtration apparatus using a membrane module is known (for example, Patent Documents 1 to 3).
  • Patent Document 1 a plurality of membrane modules, an introduction line for introducing a stock solution to the primary side of each of the membrane modules, and a secondary side of each of the membrane modules are connected and filtered by the membrane module.
  • a filtration liquid discharge line for discharging the filtrate, and at the time of backwashing, the flow path of the introduction line communicating with the membrane module to be backwashed is provided in the introduction line in a filtration device that is closed
  • the flow path from the membrane module to be backwashed during backwashing is opened and connected to the primary side of each of the membrane modules and the backwash line through which the filtrate flows as backwashing liquid.
  • Patent Document 2 in a method of operating a membrane separation apparatus having a plurality of membrane modules having a common permeate line, the permeate from other membrane modules is used when backwashing is performed in some membrane modules.
  • a method of operating a membrane separation device characterized in that it is supplied to the secondary side of the membrane module to be backwashed by the discharge pressure and then pressurized gas is supplied to the secondary side.
  • Patent Document 3 discloses that in a membrane filtration apparatus including a plurality of membrane modules, a membrane passage that performs backwashing is directly passed with membrane permeated water obtained from another membrane module and backwashed. Equipped with a fluid passage switching mechanism for switching, a compressor and air piping for supplying pressurized air to each membrane module, stops the introduction of raw water into the membrane module performing backwashing, and instead pressurizes from the compressor Introduce air to the primary side of the membrane module for backwashing and introduce permeated water from other membrane modules to the secondary side of the membrane module for backwashing to perform backwashing or backwashing.
  • a membrane filtration device configured to supply pressurized air to the secondary side of a membrane module that performs washing, mix in backwash water, and backwash with a gas-liquid mixed fluid.
  • the main pipe is connected, and the raw water main pipe Branch pipes are branched, the end side of each raw water branch pipe is connected to the raw water inlet of each membrane module, each raw water branch pipe is provided with an open / close valve, and the concentrated water outlet of each membrane module is connected via the pipe
  • the three-way valve is connected to an inflow port of the three-way valve, and each of the three-way valves has two outflow ports. One of the outflow ports is connected to a branch pipe for circulating the concentrated water.
  • one end of the branch pipe for backwash drainage is connected to the other outflow port of the three-way valve, and the other end of the branch pipe is connected to the main pipe for backwash drainage discharge
  • One end of a branch pipe for extracting permeate is connected to the permeate outlet of the membrane module, and the other end of the branch pipe is connected to a main pipe for extracting permeate, Raw water branch piping
  • the end side of the air branch pipe is connected to the portion between each on-off valve and each membrane module, the upstream end side of each air branch pipe is connected to the air main pipe, and this air main pipe is connected to the compressor.
  • Patent Document 4 is a coagulation filtration apparatus for filtering water to be treated, which has flocs formed by adding a flocculant, with a membrane module, and is provided with an addition unit for adding the flocculant to the water to be treated.
  • An aggregating and filtering apparatus comprising: a stirrer that stirs water to be treated with a flocculant added downstream of the adding unit; and the membrane module that is disposed downstream of the agitator. It is disclosed.
  • a water treatment method using ferric hydroxide colloid is known.
  • a ferrous salt aqueous solution and a positively charged ferric hydroxide colloid solution are added to water to be treated and stirred, and then the pH of the water is adjusted to 6-8.
  • a water purification method is disclosed, in which an organic substance or an inorganic substance dissolved or dispersed in water is removed by precipitation and a porous membrane.
  • Patent Document 6 in a wastewater treatment method for reducing COD of wastewater with high COD in which phenols are dissolved, (1) ferrous chloride aqueous solution, ferric chloride aqueous solution, or ferrous chloride in an oxidized state An aqueous solution mixed with ferric chloride or an aqueous solution of ferric hydroxide colloid having an average particle size of 4 nm or more and less than 30 nm is added, or iron is generated by electrolysis of the waste water using iron as an anode.
  • the pH of the waste water is adjusted by mixing an alkaline aqueous solution or an aqueous acid solution to 5 or more and less than 9, and (3) after removing the generated precipitate, (4) with an average particle size of 10 nm or more
  • a method for treating waste water which comprises adding a ferric hydroxide colloid aqueous solution of less than 20 nm to remove precipitates.
  • a method of adding a flocculant and precipitating and removing agglomerates requires a coagulation sedimentation tank, which increases the size of the apparatus.
  • a coagulation sedimentation tank which increases the size of the apparatus.
  • it is required to reduce the size of the filtration device.
  • a foreign material will clog the filtration membrane with which a membrane module is provided, and filtration efficiency will fall.
  • it is necessary to back-wash the membrane module.
  • Patent Documents 5 and 6 disclose a water treatment technique that uses ferric hydroxide colloid and diffuses and filters pores using a porous membrane.
  • the pore diffusion / filtration method is a method of performing filtration by a cross flow method with a transmembrane pressure difference of 0.3 atm or less, and has a low raw water treatment capacity.
  • the porous flat membrane is used, there is a problem that the apparatus becomes large in order to increase the raw water treatment amount.
  • This invention is made
  • Another object of the present invention is to reduce the size of a central water purification apparatus that supplies clean water for daily use to the entire building such as a condominium and a building.
  • the method for producing domestic water for purification according to the present invention is a method for producing domestic water for purification by adding a nucleating agent to raw water and filtering with a membrane means, wherein the nucleating agent has a weight average particle diameter of 5 nm to 160 nm.
  • the ratio of the iron mass of the aqueous ferric hydroxide colloidal particles to the total mass of iron added to the raw water is set to 0.9 or more. It is characterized by that.
  • the commercially available flocculants are suitable for aggregating colloidal particles of about 100 ⁇ m to 1 ⁇ m floating in the water to be treated, for example, but agglomerate ionic substances and ionic molecules such as small metal ions. Is difficult.
  • the present inventors used an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm (hereinafter sometimes simply referred to as “aqueous dispersion of ferric hydroxide”). For example, the inventors have found that the effect of capturing ionic substances and ion molecules such as heavy metal ions having a small particle size is increased, and the present invention has been completed.
  • the aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm used in the present invention adsorbs ionic impurities contained in the raw water by the charge effect due to the potential, It is considered that the particle grows as the center and has an effect of increasing the particle size. Furthermore, an aggregate in which particles centering on a nucleating agent are aggregated may be generated. In the present invention, an aqueous dispersion of ferric hydroxide colloidal particles having such an effect is called a “nucleating agent” and is distinguished from a general flocculant.
  • the general flocculant is intended to agglomerate impurities, to enlarge and precipitate the aggregate, and to remove it, in the method for producing purified water for daily use of the present invention, the flocculating agent formed by the “nucleating agent” It is characterized in that it is filtered directly by membrane means without precipitating the product.
  • the nucleating agent if an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm is used as the nucleating agent, the particle size of the aggregate formed by the “nucleating agent” is controlled, There is an effect of suppressing the blockage of the membrane means. As a result, a certain amount of clean water for daily use can be stably supplied.
  • the apparatus used in the method for producing domestic purified water according to the present invention includes a raw water supply channel, a raw water supply unit that is disposed in the raw water supply channel, and feeds the raw water, and a plurality of branching the raw water supply channel into at least two or more.
  • a separation tank that precipitates and separates agglomerates generated by the addition of a nucleating agent.
  • the present invention it is possible to provide clean water for daily use from which ionic impurities such as heavy metal ions and arsenic are efficiently removed. Moreover, according to this invention, the water purifier with high backwashing efficiency is obtained.
  • the water purifier of the present invention can be reduced in size.
  • the manufacturing method of domestic water purification of this invention is a manufacturing method of domestic water purification which adds a nucleating agent to raw
  • a nucleating agent Using an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm, the mass of iron in the aqueous dispersion of ferric hydroxide colloidal particles relative to the total mass of iron added to the raw water The ratio is made 0.9 or more.
  • ionic impurities such as heavy metal ions having a small particle size contained in the raw water are captured by the nucleating agent and efficiently removed.
  • raw water to be treated by the method for producing water for daily life of the present invention will be described.
  • the raw water include natural water or tap water.
  • Natural water is fresh water that exists in the natural world such as well water, groundwater, rainwater, rivers, ponds, and lakes.
  • Tap water is purified water supplied from a water purification facility.
  • the raw water to be treated in the present invention does not include industrial wastewater, industrial wastewater and the like. This is because industrial wastewater and industrial wastewater have many types of impurities and have a high concentration of impurities, so that the impurities cannot be removed even by the present invention and are not acceptable as clean water for daily use.
  • natural water can be removed.
  • the ionic impurities contained in the raw water include heavy metal ions such as iron (Fe 2+ , Fe 3+ ), cadmium (Cd 2+ ), copper (Cu 2+ ), lead (Pb 2+ ), arsenic (AsO 4 3 ⁇ , etc.) Metal ions such as aluminum (Al 3+ ) can be removed. According to the present invention, both anionic impurities and cationic impurities can be removed.
  • an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm used as a nucleating agent in the present invention will be described.
  • the aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm used in the present invention adsorbs ionic impurities contained in the raw water by the charge effect due to electric potential, and the particles are mainly composed of colloidal particles. Are believed to grow and become larger in particle size. Furthermore, the grown particles centering on the nucleating agent may aggregate to form an aggregate.
  • the present invention by using a ferric hydroxide colloid particle aqueous dispersion having a weight average particle size of 5 nm to 160 nm as a nucleating agent, an ionic impurity having a small particle size contained in raw water (heavy metal ions, arsenic, Ionic substances such as fluorine) can be efficiently captured.
  • the weight average particle size of the nucleating agent is preferably controlled to 5 nm to 160 nm.
  • the weight average particle size of the aqueous dispersion of ferric hydroxide is more preferably 10 nm or more, further preferably 15 nm or more, preferably 50 nm or less, more preferably 40 nm or less, and further preferably 25 nm or less. If the weight average particle size becomes too small, the aqueous dispersion of ferric hydroxide may permeate the membrane means. Moreover, when the weight average particle diameter becomes too large, the effect of capturing ionic molecules such as arsenic and heavy metals is reduced. In the present invention, the weight average particle size of the aqueous dispersion of ferric hydroxide is measured by a dynamic light scattering method using, for example, DLS-8000 / 6500 manufactured by Otsuka Electronics Co., Ltd.
  • ferric hydroxide colloidal particle aqueous dispersion for example, a colloidal particle formed by adsorbing a negatively charged counterion on the outside of a positively charged ferric ion particle is dispersed in water.
  • the counter ion include sulfate ion, hydroxide ion, and chlorine ion.
  • FIG. 1 is an explanatory view schematically illustrating ferric hydroxide colloidal particles 100 used as a nucleating agent.
  • a layer 102 made of hydroxide ions (OH ⁇ ) as counter ions is formed on the surface of the nucleus 101 made of positively charged iron ions (Fe 3+ ).
  • the ferric hydroxide colloidal particles 100 have a high affinity with water and a high stability in water because the layer 102 made of hydroxide ions is formed outside the core 101 made of iron ions. .
  • a layer 103 made of iron ions (Fe 3+ ) Layers 104 made of hydroxide ions (OH ⁇ ) are alternately formed, and the particle diameter is increased.
  • FIG. 3 is an explanatory view schematically illustrating an aspect in which ferric hydroxide colloidal particles, which are nucleating agents, capture heavy metal ions (X ⁇ ).
  • X ⁇ heavy metal ions
  • a layer 102 made of hydroxide ions (OH ⁇ ) as counter ions is formed on the surface of the nucleus 101 made of positively charged iron ions (Fe 3+ ). Since the layer 102 of hydroxide ions (OH ⁇ ) is negatively charged, it attracts cations (M + ) and hydrogen ions (H + ) contained in the nucleating agent and raw water. As a result, a layer 105 made of positively charged cations is formed outside the layer 102 made of hydroxide ions.
  • the layer 105 made of cations attracts heavy metal ions (X ⁇ ) and hydroxide ions (OH ⁇ ), and the layer 106 made of anions is formed outside the layer 105 made of cations. Is done.
  • the electric charge effect by an electric potential becomes weak as it leaves
  • the nucleating agent grows particles by adsorbing the counter ion around the core of the metal ion. At that time, ionic impurities in the raw water are trapped inside the particles.
  • FIG. 4 shows a mode in which nucleated particles aggregate to form further aggregates.
  • the aqueous ferric hydroxide colloidal particle dispersion can be prepared, for example, by adding sodium hydroxide to ferric chloride and adjusting the pH to about 2.7 and heating. .
  • the average particle diameter can be controlled by the amount of iron ions added for the growth of trivalent iron ions and hydroxide ions or colloidal particles.
  • the aqueous dispersion of ferric hydroxide colloidal particles preferably has a pH adjusted to 1.5 to 4.0. This is because as the pH increases, the stability of the ferric hydroxide colloid may decrease. If the ferric hydroxide colloidal particle aqueous dispersion contains ferric chloride or other iron ions, the size of the aggregates generated from the raw water by the nucleating agent increases, and the membrane means is used. Since it becomes easy to block, by adjusting the amount of ferric chloride and sodium hydroxide, the aqueous dispersion of ferric hydroxide colloidal particles does not contain ferric chloride-derived iron ions. It is better to do so.
  • the total iron concentration of the aqueous dispersion of ferric hydroxide colloidal particles used as a nucleating agent is determined by the transportability of the nucleating agent and Considering the transportation cost, a high concentration is preferable. That is, the total iron concentration is preferably 1,000 mg / L or more, more preferably 3,000 mg / L or more, and further preferably 4,000 mg / L or more. However, if it exceeds 10,000 mg / L, it is self-aggregated to produce a precipitate, so that it is preferably 10,000 mg / L or less, more preferably 8,000 mg / L or less, and even more preferably 6,000 mg / L or less.
  • the total iron concentration is the total mass (mg) of iron (Fe) contained in 1 L of the aqueous dispersion of ferric hydroxide colloid particles. Total iron concentration is measured by ICP mass spectrometry.
  • nucleating agent for example, an aspect of adding the nucleating agent to the raw water stored in the raw water tank, an aspect of adding the nucleating agent to the raw water in the raw water supply path for supplying the raw water to the membrane means And so on.
  • the nucleating agent it is preferable to add the nucleating agent to the raw water immediately before the membrane means. If the aggregate particle size becomes too large, the aggregate may block the pores of the membrane means.
  • the amount of nucleating agent (aqueous dispersion of ferric hydroxide colloidal particles) added to the raw water exhibits a removal effect as the concentration increases, so that the total iron concentration is preferably 0.05 mg / L or more, 0 .3 mg / L or more is more preferable, and 0.5 mg / L or more is more preferable.
  • the amount of the nucleating agent added to the raw water is preferably 9 mg / L or less, more preferably 6 mg / L or less, and further preferably 4 mg / L or less in terms of total iron concentration. If it is 9 mg / L or less, the manufacturing cost can be reduced and the nucleating agent tank can be downsized.
  • the upper limit of the nucleating agent concentration relative to the raw water is preferably 3 mg / L, more preferably 2 mg / L, from the viewpoint of cost reduction. L is more preferable.
  • the addition amount of the nucleating agent is represented by the total mass (mg) of the iron component (Fe) of the nucleating agent (aqueous dispersion of ferric hydroxide colloid particles) added to 1 L of raw water.
  • the ratio of the mass of iron contained in the aqueous dispersion of ferric hydroxide colloid particles to the total mass of iron added to the raw water is set to 0.9 or more. That is, when an iron-containing aqueous liquid other than the aqueous dispersion of ferric hydroxide colloid particles is added to the raw water, the mass of iron contained in the aqueous dispersion of ferric hydroxide colloid particles is A, Aqueous dispersion of ferric hydroxide colloidal particles relative to the total mass of iron added to the raw water (A + B), where B is the mass of iron contained in the iron-containing aqueous liquid other than the aqueous dispersion of ferric colloidal particles
  • the mass ratio (A / (A + B)) of iron A contained in the product is preferably 0.9 or more, more preferably 0.95 or more, and even more preferably 0.99 or more.
  • the iron content of the aqueous dispersion of ferric hydroxide colloidal particles includes, for example, the iron content of the colloidal particles themselves and the colloidal particles.
  • the iron content derived from ferric chloride used as a raw material is included.
  • the iron-containing aqueous liquid other than the aqueous dispersion of ferric hydroxide colloidal particles include a ferrous chloride aqueous solution and a ferric chloride aqueous solution.
  • the iron content contained in the iron-containing aqueous liquid may be adsorbed on the colloidal particles to increase the particle size of the nucleating agent.
  • the value of (A / (A + B)) may be set to 0.99 or less, and may be set to 0.98 or less.
  • the iron concentration is measured by ICP mass spectrometry.
  • the raw water may contain iron ions.
  • the mass C of iron contained in the raw water, the mass of iron contained in the aqueous dispersion of ferric hydroxide colloid particles is A, and iron content other than the aqueous dispersion of ferric hydroxide colloid particles is contained.
  • the mass of iron contained in the aqueous liquid is B
  • the value of A / (A + B + C) is preferably 0.9 or more, more preferably 0.95 or more, and 0.99 or more. More preferably.
  • the iron contained in the raw water or the iron contained in the iron-containing aqueous liquid is adsorbed on the colloidal particles to increase the particle size of the nucleating agent.
  • the value of (A / (A + B + C)) may be set to 0.99 or less, and may be set to 0.98 or less.
  • the iron concentration is measured by ICP mass spectrometry.
  • the pH of raw water is preferably 4.5 or more, more preferably 5 or more, preferably 7.5 or less, more preferably 7 or less, and even more preferably 6.5 or less.
  • the pH may be adjusted by adding an alkali or acid to the raw water. Examples of the alkali include alkali solutions such as sodium hydroxide, potassium hydroxide, and ammonia.
  • Sodium hydroxide or potassium hydroxide is preferable and sodium hydroxide is more preferable because it is inexpensive and easy to handle.
  • the acid include hydrochloric acid, nitric acid, acetic acid, dilute sulfuric acid, and the like, and hydrochloric acid and dilute sulfuric acid are preferable, and hydrochloric acid is more preferable because it is inexpensive and easy to handle.
  • the membrane means used in the present invention removes foreign matters such as fine particles and turbidity in raw water and discharges purified water.
  • the membrane means include filtration membranes such as reverse osmosis membranes (RO membranes), nanofiltration membranes (NF membranes), microfiltration membranes (MF membranes), and ultrafiltration membranes (UF membranes).
  • RO membranes reverse osmosis membranes
  • NF membranes nanofiltration membranes
  • MF membranes microfiltration membranes
  • UF membranes ultrafiltration membranes
  • a membrane means a microfiltration membrane (MF membrane) and an ultrafiltration membrane (UF membrane) are preferable from the viewpoint that raw water can be filtered at a relatively low pressure and low cost.
  • an ultrafiltration membrane (UF membrane) or a microfiltration membrane (MF membrane) is not used as the membrane means.
  • the ultrafiltration membrane (UF membrane) and microfiltration membrane (MF membrane) have larger pore diameters than the heavy metal ions, and the heavy metal ions in the raw water permeate the membrane means. Therefore, when removing heavy metal ions in raw water by a membrane means, it is necessary to use a reverse osmosis membrane (RO membrane) or nanofiltration membrane (NF membrane) having a small pore diameter.
  • RO membrane reverse osmosis membrane
  • NF membrane nanofiltration membrane
  • a hollow fiber membrane as the membrane means.
  • a filtration method all raw water is filtered through a filtration membrane to make purified water (dead-end filtration method), and raw water is run parallel to the surface of the filtration membrane.
  • a cross-flow filtration method that discharges both purified water that has been filtered through a filtration membrane
  • a full-volume filtration method that can increase the amount of purified water.
  • B / A is 1 to 20 More preferably.
  • B / A is preferably 2 or more, more preferably 5 or more, and preferably 10 or less, more preferably 7 or less.
  • the pore diameter B (nm) of the membrane means can be determined according to the bubble point method (JIS K 3832).
  • the size of the eyes is classified according to the molecular weight cut off using the substance to be separated as an index. That is, classification is performed based on the molecular weight of the marker that can be separated on the target membrane. Representative markers are shown in the table below.
  • the membrane rejection is defined by the ratio of the concentration of the target substance on the permeate side to the concentration of the target substance on the supply liquid side, and the separation performance can be evaluated.
  • the molecular weight of the target substance having a rejection rate of about 90% is defined as the fractional molecular weight.
  • the transmembrane pressure difference of the membrane means is preferably more than 0.03 MPa, more preferably 0.04 MPa or more, and further preferably 0.05 MPa or more. Preferably, it is 0.45 MPa or less, more preferably 0.3 MPa or less, further preferably 0.2 MPa or less, and particularly preferably 0.15 MPa or less.
  • the pressure on the primary side of the membrane means is preferably 0.08 MPa or more, more preferably 0.13 MPa or more, further preferably 0.15 MPa or more, preferably 0.50 MPa or less, more preferably 0.35 MPa or less. 0.25 MPa or less is more preferable.
  • the pressure on the secondary side of the membrane means is preferably 0.05 MPa or more, more preferably 0.10 MPa or more, further preferably 0.12 MPa or more, preferably 0.30 MPa or less, more preferably 0.25 MPa or less. 0.20 MPa or less is more preferable.
  • the ratio (V / S, (m / hr)) of the filtration amount V (m 3 ) per hour to the total filtration area S (m 2 ) of the membrane means is 0 .05 or more, preferably 0.1 or more, more preferably 0.3 or more, particularly preferably 0.5 or more, and 3.0 or less. Preferably, it is 2.5 or less, more preferably 2.0 or less.
  • the ratio is 0.05 or more and 3.0 or less, the amount of raw water treated per unit filtration area becomes a desired range.
  • the amount of raw water treated per unit filtration area is extremely small, and in order to increase the amount of raw water treated, the filtration area is increased.
  • the filtration device becomes larger.
  • a chemical solution may be added to the purified water for domestic use obtained by filtering with a membrane means, if necessary.
  • medical solution For example, hypochlorous acid, sodium hypochlorite, hypochlorous acid aqueous solution, etc. can be mentioned. Among these, it is preferable to use a sodium hypochlorite aqueous solution. By adding sodium hypochlorite, it ionizes to hypochlorite ions in water, and part of it reacts with water to form hypochlorous acid.
  • the chlorine concentration in the obtained purified water is preferably 0.3 mg / L or more in consideration of the relationship between sterilizing power and chlorine removal efficiency in the secondary water purification device. 0.4 mg / L or more is more preferable, 0.5 mg / L or more is more preferable, 0.8 mg / L or less is preferable, and 0.7 mg / L or less is more preferable.
  • the domestic purified water obtained by the production method of the present invention includes domestic water used for cooking, washing, bathing, showering, and drinking water.
  • the production method of the present invention is suitable for producing drinking water.
  • the water purification apparatus for domestic use of the present invention is an apparatus used in the method for manufacturing water for domestic use of the present invention, Raw water supply channel, Raw water supply means that is disposed in the raw water supply path and feeds raw water, A plurality of raw water branch paths that branch the raw water supply path into at least two or more; A membrane module that is disposed in the plurality of raw water branches and includes a plurality of membrane means for filtering raw water; A discharge path connected to a primary side of the plurality of membrane modules; A plurality of water purification branches connected to the secondary side of the plurality of membrane modules; A plurality of water purifying branches, and The primary side of the membrane module is provided with means for supplying a nucleating agent to raw water, and is not provided with a separation tank for precipitating and separating aggregates generated by the addition of the nucleating agent.
  • the nucleating agent contacts the impurity in the raw water, and the nucleating agent captures the impurity.
  • the nucleating agent that has captured the impurity cannot pass through the membrane means, and is removed from the raw water together with the impurity.
  • Means for supplying a nucleating agent comprising an aqueous dispersion of ferric hydroxide colloid particles having a weight average particle diameter of 5 nm to 160 nm is not particularly limited.
  • the water purifier of this invention does not provide the separation tank which precipitates and isolate
  • the production apparatus for domestic water purification of the present invention is configured so that the membrane module can be back-washed. This is for removing clogging of the membrane module and supplying clean water stably for a long period of time.
  • the manufacturing apparatus of this invention is demonstrated based on the aspect of the central water purifier comprised so that back washing
  • the central water purification apparatus 1 shown in FIG. 5 is disposed in the raw water supply path 3, the raw water supply path 3, a raw water supply means P ⁇ b> 1 that feeds the raw water, and a plurality of branches that branch the raw water supply path 3 into at least two or more A raw water branch 5A, 5B, a plurality of membrane modules 9A, 9B that are disposed in the plurality of raw water branches 5A, 5B and filter raw water, and membrane means 9c that filters the raw water included in the membrane modules 9A, 9B.
  • the passage 13 is provided with a tank 37 for storing a nucleating agent, and a supply means P3 for supplying the nucleating agent.
  • the side on which raw water is supplied to the membrane means is referred to as the primary side
  • the side from which the purified water is discharged from the membrane means is referred to as the secondary side.
  • the raw water supply path 3 supplies raw water to be subjected to purification treatment such as tap water and natural water.
  • the raw water supply channel 3 is preferably connected to a raw water tank that stores tap water from a water main supplied to a building such as an apartment, an apartment, a building, a hotel, or a plurality of detached houses. It can also be connected directly to the main.
  • the raw water supply path 3 is constituted by a pipe line having a predetermined pipe diameter.
  • the raw water supply path 3 preferably includes an inflow valve (first valve V1) for opening and closing the raw water supply path 3.
  • the inflow valve may be a check valve.
  • raw water supply means P1 for sending raw water is disposed.
  • the raw water supply means P1 include a vertical multi-stage centrifugal pump, a horizontal multi-stage centrifugal pump, and a positive displacement pump. Among these, it is preferable to use a vertical multistage centrifugal pump as the raw water supply means P1 because the raw water is stably pressurized and fed.
  • the downstream end of the raw water supply path 3 is connected at the branch point 4 to the upstream ends of the raw water branch paths 5A and 5B that branch the raw water supply path 3 into a plurality.
  • the raw water branch paths 5A and 5B are constituted by pipe lines having a predetermined pipe diameter.
  • the raw water branch paths 5A and 5B include inflow valves (second valve V2 and third valve V3) for opening and closing the raw water branch paths 5A and 5B, respectively.
  • the downstream ends of the raw water branch paths 5A and 5B are connected to membrane modules 9A and 9B that filter the raw water.
  • the membrane modules 9A and 9B remove foreign matters such as fine particles and turbidity in the raw water, and discharge purified water.
  • the membrane modules 9A and 9B include membrane means 9c for filtering raw water and a cylindrical container 9d for housing the membrane means 9c.
  • the raw water region 9e to which raw water is supplied and the purified water filtered by the membrane means flow into the cylindrical container 9d with the membrane means 9c for filtering the raw water interposed therebetween. It is preferable to provide the purified water region 9f.
  • the membrane modules 9A and 9B are provided with a raw water inlet 9g and a purified water outlet 9h, and further with a concentrated water outlet 9i for discharging concentrated water.
  • the raw water inlet 9g and the concentrated water outlet 9i are connected to the raw water area 9e of the membrane modules 9A and 9B, and the purified water outlet 9h is connected to the purified water area 9f of the membrane modules 9A and 9B.
  • the membrane module may be either an external pressure type or an internal pressure type, preferably an internal pressure type.
  • membrane it is preferable to use a hollow fiber membrane comprising an ultrafiltration membrane (UF membrane) or a microfiltration membrane (MF membrane).
  • UF membrane ultrafiltration membrane
  • MF membrane microfiltration membrane
  • the water purifier of the present invention has means for supplying a nucleating agent.
  • the means for supplying the nucleating agent includes a tank 37 for storing the nucleating agent, a supplying means P3 for supplying the nucleating agent, and a nucleating agent supply path 6.
  • the nucleating agent is supplied to the raw water stored in the raw water tank 35. It is also preferable to provide the raw water tank 35 with a stirring function such as stirring by a stirring blade or stirring by a circulation pump.
  • the stirring function can increase the contact efficiency between the nucleating agent and various ions, and can contribute to increasing the particle size of the nucleating agent.
  • nucleating agent supply path 6 is composed of a pipe having a predetermined pipe diameter.
  • the discharge path is a flow path for discharging the backwash water when the membrane module is mainly backwashed.
  • the said discharge path should just be connected to the upstream of the membrane means 9c with which membrane module 9A, 9B is equipped, for example, the aspect connected to the raw
  • the discharge passages 7A and 7B are preferably composed of pipe passages having a predetermined pipe diameter, and are provided with valves (fourth valve V4 and fifth valve V5) for opening and closing the respective passages.
  • the discharge paths 7A and 7B may further merge.
  • the upstream ends of the purified water branch paths 11A and 11B are connected to the downstream side of the membrane modules 9A and 9B.
  • the purified water branch paths 11A and 11B are connected to the purified water discharge port 9h of the membrane modules 9A and 9B.
  • the downstream sides of the purified water branch paths 11A and 11B are formed so that the purified water branch paths 11A and 11B connected at the junction 17 and connected to the plurality of membrane modules communicate with each other.
  • the junction 17 is provided with a three-way cock 49 for switching the flow path. Instead of the three-way cock 49, an open / close valve for switching the flow path may be provided on the downstream side of the purified water branch paths 11A and 11B.
  • the raw water branch 5A and 5B are preferably provided with pressure gauges 14A and 14B for measuring the pressure of the raw water flowing in the raw water branch. Moreover, it is preferable that the pressure gauges 16A and 16B which measure the pressure of the purified water which flows through the inside of the purified water branch are provided in the purified water branches 11A and 11B.
  • the purified water path 13 is connected to the junction 17 of the purified water branch paths 11A and 11B.
  • the water purification channel 13 is provided with a valve (eighth valve V8) for opening and closing the water purification channel 13.
  • the water purification path 13 is composed of a pipe having a predetermined pipe diameter. It is preferable that the purified water path 13 is provided with a purified water discharge path 19 for discharging purified water.
  • the purified water discharge path 19 is constituted by a pipeline having a predetermined pipe diameter, and includes a valve (a ninth valve V9) for opening and closing the purified water discharge path 19.
  • the control means 21 preferably includes, for example, an inverter control unit 23, a valve control unit 25, a membrane differential pressure calculation unit 27, a display 29, a manual switch 31, a timer 33, and the like.
  • the water purifier 1 in FIG. 5 has an inverter control unit 23 that controls the raw water supply means P1. It is preferable to control the raw water pressure supplied by the raw water supply means by controlling the raw water supply means P1 with an inverter.
  • the inverter control unit 23 controls the raw water supply means P1 so that the pressure of the raw water is substantially constant during the production of purified water, and controls the raw water supply means P1 so that the pressure of the raw water pulsates during the reverse cleaning operation. .
  • the membrane differential pressure calculation unit 27 receives the measurement values of the pressure gauges 14A, 14B, 16A, and 16B, and calculates the transmembrane pressure difference between the primary side and the secondary side of the membrane modules 9A and 9B. For example, the membrane differential pressure calculation unit 27 instructs the valve control unit 25 to switch the valve so as to perform the purified water production operation or the reverse cleaning operation in accordance with the data of the transmembrane differential pressure.
  • the valve control unit 25 opens and closes the valve based on manual switch operation data, transmembrane pressure data supplied by the membrane pressure calculation unit, time data supplied by a timer, and the like.
  • the valve controller and each valve are preferably connected by wire or wirelessly.
  • the timer 33 measures the time of the normal filtration operation and the time of the back washing operation, and when each operation time reaches a predetermined time, the water purification manufacturing operation or the back washing operation is performed on the valve control unit 25. Thus, it is possible to instruct switching of the valve.
  • the indicator 29 can display, for example, the pressure value received from the pressure gauge, the transmembrane pressure difference, the current operation process, and the like.
  • the purified water obtained by the purified water manufacturing apparatus 1 is shown in figure so that it may be supplied to the water receiving tank 45, the water receiving tank 45 is not necessarily required.
  • the raw water tank 35 and the water receiving tank 45 include level meters L1 and L2.
  • the valve control unit 25 switches the valve so that the normal filtration operation and the reverse cleaning operation are switched when a certain amount of raw water is processed. You may be instructed.
  • the membrane module is described based on a form having the first membrane module 9A and the second membrane module 9B, but the number of membrane modules is preferably two or more.
  • the aspect which has two or more pairs of membrane module sets which consist of a 1st membrane module and a 2nd membrane module can be mentioned. Since the water purifier of the present invention has a plurality of pairs of membrane module sets each composed of a first membrane module and a second membrane module, the amount of raw water treated can be increased.
  • the purified water obtained from one membrane module in a filtered state is configured to be used as backwash water for another one membrane module to be backwashed. That is, the ratio of the number of membrane modules in a filtered state to the membrane module to be backwashed is 1: 1.
  • the purified water obtained from a plurality of membrane modules in a filtered state may be merged and used as backwash water for one membrane module to be backwashed, or 1 in a filtered state. You may comprise so that the purified water obtained from one membrane module may be branched and used as the backwash water of the several membrane module used as the backwash object.
  • membrane module to be backwashed multiple: 1
  • the pressure of backwashing water becomes too high, and there is a risk of damaging the filtration membrane provided in the membrane module to be backwashed.
  • the membrane module to be backwashed 1: many
  • the pressure of backwashing water is lowered, so that the backwashing efficiency may be lowered. Therefore, it is preferable that the ratio of the number of membrane modules in a filtered state and the number of membrane modules to be backwashed is 1: 1.
  • the water purification apparatus of the present invention can be suitably used as a central water purification apparatus that can supply purified water to buildings such as apartments, apartments, buildings, hotels, and multiple houses.
  • the amount of purified water supplied from the central water purification apparatus is appropriately set according to the number of supply destinations and the amount of water used.
  • the supply amount of purified water of the central water purification device is preferably 3,000 L / hour or more, and 4,000 L / hour. More preferably, 5,000 L / hour or more is more preferred, 8,000 L / hour or less is preferred, 7,000 L / hour or less is more preferred, and 6,000 L / hour or less is more preferred.
  • the water purification method using the water purification apparatus of FIG. 5 supplies raw water in parallel to a plurality of membrane modules having at least a first membrane module and a second membrane module, and filters the raw water through the plurality of membrane modules.
  • FIG. 6 is a view showing a water flow state of the water purifier 1 of the present invention in the water purification production process.
  • the first to third valves V1 to V3 and the eighth valve V8 are released, and the fourth to seventh valves V4 to V7 and the ninth valve V9 are closed.
  • a raw water treatment line is formed in which the raw water supply path 3, the raw water branch paths 5A and 5B, the purified water branch paths 11A and 11B, and the purified water path 13 communicate with each other through the membrane modules 9A and 9B.
  • the valve opening / closing operation may be automatic control by the valve control unit or may be manually controlled.
  • the raw water supply means P1 preferably pressurizes the raw water and sends it to the raw water supply path.
  • the pressure of the raw water is preferably set as appropriate according to the allowable pressure of the membrane module to be used.
  • the allowable pressure is about 0.35 MPa
  • the pressure Pf of the pressurized raw water is preferably 0.08 MPa or more, 0.13 MPa or more is more preferable, 0.15 MPa or more is more preferable, 0.35 MPa or less is preferable, 0.32 MPa or less is more preferable, and 0.30 MPa or less is more preferable.
  • the pressure Pf of the pressurized raw water exceeds the allowable pressure, the filtration membrane is easily damaged. Moreover, if the pressure Pf of the pressurized raw water is too low, the flow rate of the raw water is reduced. In the purified water production process, the pressure Pf of the raw water is preferably substantially constant.
  • the raw water branches at the branch point 4 and is supplied to the first and second membrane modules 9A and 9B through the raw water branch paths 5A and 5B.
  • the raw water is filtered by the first and second membrane modules 9A and 9B. Foreign matter and turbidity contained in the raw water are removed by the membrane module. Impurities contained in the raw water (heavy metal ions, arsenic, fluorine, etc.) are captured by the nucleating agent and removed from the raw water by the membrane means.
  • the fourth and fifth valves V4 and V5 are opened, and the concentrated water is filtered while being discharged from the discharge passages 7A and 7B.
  • a method may be adopted.
  • the purified water discharged from the first and second membrane modules 9A and 9B merges at the junction 17 through the purified water branch paths 11A and 11B, and flows out to the purified water path 13, respectively.
  • raw water is supplied to one of the first membrane module or the second membrane module and filtered, and at least a part of the obtained purified water is used as backwash water from the downstream side of the other membrane module.
  • the other membrane module is back-washed by flowing back to the side.
  • the first membrane module is operated in the filtration state and the second membrane module is backwashed
  • the first and second valves V1, V2, the fifth valve V5, and the eighth valve V8 are released, and the third, fourth, The sixth and seventh valves V3, V4, V6, V7 and the ninth valve V9 are closed.
  • the valve opening / closing operation may be automatic control by the valve control unit or may be manually controlled.
  • a raw water treatment line is formed in which the raw water supply path 3, the raw water branch path 5A, the purified water branch path 11A, and the purified water path 13 communicate with each other through the membrane module 9A. Further, a backwash line is formed in which the purified water branch path 11B and the discharge path 7B communicate with each other via the second membrane module 9B.
  • the backwash water that has entered the second membrane module 9B passes through the membrane means 9c disposed in the second membrane module 9B, and flows out from the upstream concentrated water discharge port 9i to the discharge path 7B. At this time, the foreign matter adhering to the membrane means 9c of the second membrane module 9B is released and flows out into the discharge path 7B together with the backwash water.
  • the foreign matter adhering to the backwash water and the second membrane module 9B is discharged out of the water purifier from the discharge path 7B connected to the concentrated water discharge port 9i.
  • the foreign matter adhering to the film means 9c includes a nucleating agent adhering to the film means 9c and an aggregate formed by the nucleating agent.
  • the remaining portion of the purified water discharged from the first membrane module 9A flows out to the purified water channel 13. Thereby, it is possible to continue discharging a certain amount of purified water while backwashing the second membrane module 9B.
  • the eighth valve V8 may be closed and all the purified water discharged from the first membrane module 9A may be backwashed water.
  • a line in which the purified water branch path 11B, the second membrane module 9B, and the discharge path 7B communicate with each other is adopted as the backwash line.
  • the purified water branch path 11B, the raw water branch path 5B, and the discharge path 15B are adopted.
  • the raw water supply means P1 may supply the raw water to the first membrane module 9A while pulsating the water pressure of the raw water.
  • Supplying the raw water to the first membrane module 9A while pulsating the water pressure of the raw water pulsates the purified water discharged from the first membrane module 9A, that is, the backwash water pressure, so that the reverse of the second membrane module 9B This is because the cleaning efficiency is increased.
  • As a method of pulsating the water pressure of the raw water for example, it is preferable to continuously change the rotation speed of the raw material supply means P1 by the inverter control unit 23.
  • the first, third valves V1, V3, the fourth valve V4, and the eighth valve V8 are released,
  • the second, fifth, sixth, and seventh valves V2, V5, V6, V7, and the ninth valve V9 may be closed to perform the same operation.
  • the valve opening / closing operation may be automatic control by the valve control unit or may be manually controlled.
  • a raw water treatment line is formed in which the raw water supply path 3, the raw water branch path 5B, the purified water branch path 11B, and the purified water path 13 communicate with each other through the second membrane module 9B. Moreover, the purified water branch path 11A and the discharge path 7A form a backwash line communicating with the first membrane module 9A.
  • the backwash line in which the purified water branch path 11A and the discharge path 7A communicated with each other via the first membrane module 9A is adopted as the backwash line.
  • the purified water branch path 11A and A line in which the raw water branch 5A and the discharge path 15A communicate with each other via the first membrane module 9A may be adopted.
  • the method for producing purified water of the present invention in which a nucleating agent is added to raw water and filtered through a membrane module provided with membrane means includes, for example, the following steps, and includes the following steps (2) to (4) as appropriate: It is preferable to carry out switching.
  • (1) Step of adding a nucleating agent to raw water (2) Purified water production step of filtering raw water through both the first membrane module and the second membrane module (3) The first membrane module is put into a filtered state, and the second membrane module (4) Backwashing process in which the second membrane module is in the filtered state and the first membrane module is in the backwashed state.
  • manual switch operation data, membrane differential pressure calculation This is preferably performed based on differential pressure data supplied by the unit, time data supplied by the timer, and the like.
  • the time of the water purification production process may vary from several minutes to several hours to several days.
  • the time for the back washing step is, for example, preferably 30 seconds or more, more preferably 1 minute or more, particularly preferably 5 minutes or more, preferably 20 minutes or less, more preferably 10 minutes or less, and particularly preferably 7 minutes or less.
  • the present invention has been described based on preferred embodiments, but the present invention is not limited to the above-described embodiments, and the shape, configuration, arrangement, and the like of each embodiment are within the scope of the present invention. Materials, processes, and the like can be changed as appropriate. In addition, the definitions of the configuration, arrangement, material, shape, numerical range, process, and the like shown in each embodiment can be applied independently or in combination of any two or more rules.
  • nucleating agent aqueous dispersion of ferric hydroxide colloidal particles
  • An aqueous dispersion of viscosity was obtained.
  • particle size control of nucleating agent The weight average particle diameter of the nucleating agent was proportional to the ratio of ferric chloride and was controlled by the mixing ratio of ferric chloride and sodium hydroxide.
  • Flocculant As comparative flocculants, the following commercial products were used.
  • Flocculant 1 Polyglutamic acid-based flocculant
  • Flocculant 2 Polyglutamic acid-based flocculant (including magnetic substance)
  • Flocculant 3 Inorganic flocculant (mainly Shirasu)
  • Coagulant 4 Calcium salt type coagulant
  • Coagulant 5 Zeolite type coagulant
  • Method removal test (1) Removal test for various metals A nucleating agent (an aqueous dispersion of ferric hydroxide colloid particles having a weight average particle diameter of about 10 nm) was added to 50 mL of raw water in which various metal components were adjusted to predetermined concentrations. . The nucleating agent was added so that the total iron concentration relative to the raw water was 0.6 mg / L. After the nucleating agent was added, the liquid to be treated was stirred for 1 minute to generate aggregates. Thereafter, the liquid to be treated was filtered through a filter membrane (filter paper: Advantec No. 2, pore size: 5 ⁇ m), and the removal rate was calculated. The calculated removal rate is shown in Table 2.
  • filter paper Advantec No. 2, pore size: 5 ⁇ m
  • the removal load index is a comprehensive index for determining filtration performance expressed by the concentration difference before and after the filtration process ⁇ the treatment amount.
  • Cd were used as heavy metals.
  • the heavy metal concentration and the removal load index before and after the filtration treatment are shown in FIGS.
  • the removal rate of heavy metals is shown in Table 3. In a filtration experiment using filter paper, heavy metals contained in raw water may be adsorbed on the filter paper. Therefore, the overall removal rate including the filter paper and the blank test without adding the nucleating agent and the flocculant showed the removal rate (chemicals only) excluding the influence of the filter paper.
  • the nucleating agent used in the present invention shows a higher removal performance than the flocculants 1-5.
  • the purified water was manufactured using the experimental machine which combined the nucleating agent supply means and the ultrafiltration membrane (UF membrane). That is, in the raw water tank, the raw water whose metal concentration was adjusted to 0.02 mg / L was adjusted to pH 5.5, 6.5, 7.5, and 8.5, respectively. Thereafter, a nucleating agent (an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of about 10 nm) is added from the nucleating agent storage tank to a total iron concentration of 0.12 mg / L, 0.36 mg / L. , 0.6 mg / L was added to the raw water, and the liquid to be treated was stirred for 2 minutes to generate aggregates.
  • a nucleating agent an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of about 10 nm
  • the liquid to be treated was filtered using a UF membrane (Membrane Tensha, pore size: about 100 nm) under the following conditions.
  • Transmembrane differential pressure 0.11 MPa
  • Primary pressure 0.24 MPa
  • Secondary pressure 0.13 MPa
  • FIG. 13 is a graph showing the relationship between the pH of raw
  • FIG. 14 is a graph showing the relationship between the pH of raw water and the concentration of heavy metals in purified water after filtration for Pb. From the results of FIG. 13, it can be seen that the removal effect is obtained at pH 8.5, and the removal effect of As is higher when the pH is lower than 8.5. Moreover, it can be seen from the results of FIG. 14 that the effect of removing Pb is higher when the pH is higher than 5.5.
  • the nucleating agent was added to the total iron concentration of 0.12 mg / L, 0.36 mg / L, 0.6 mg. / L was added, and the liquid to be treated was stirred for 1 minute to generate aggregates.
  • the liquid to be treated was filtered through a filtration membrane (Advantec No. 2: pore size: 5 ⁇ m), and the removal rate was calculated.
  • the nucleating agent those having a weight average particle size of 15 nm, 25 nm, 50 nm, and 160 nm were used.
  • FIG. 15 is a graph showing the relationship between the As removal rate and the weight average particle size of the nucleating agent. It can be seen that the nucleating agent used in the present invention exhibits a high removal rate for As when the weight average particle diameter is in the range of 15 nm to 160 nm.
  • the central water purification apparatus of the present invention is small in size, can efficiently remove impurities such as heavy metal ions and arsenic, and has high backwashing efficiency.
  • the central water purification apparatus of this invention is suitable as a water purification apparatus which supplies purified water to the whole building, such as a condominium and a building.

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  • Chemical & Material Sciences (AREA)
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Abstract

[Problem] The present invention addresses the problem of providing a purified water production method and a water purification apparatus for efficiently removing impurities such as heavy metal ions and arsenic. The present invention also addresses the problem of reducing the size of a central water purification apparatus for supplying purified water to an entire structure such as an apartment or office building. [Solution] This production method for purified daily life water that adds a nucleating agent to raw water and filters same with a membrane means is characterized in that: for said nucleating agent, an aqueous dispersion of ferric hydroxide colloid particles of 5-160 nm weight average particle diameter is used; and the ratio of the mass of iron in the ferric hydroxide colloidal particles with respect to the total mass of iron added to the raw water is at least 0.9.

Description

生活用浄水の製造方法および生活用浄水の製造装置Method for producing water for daily life and apparatus for producing water for daily life
 本発明は、水処理技術に関するものである。 The present invention relates to water treatment technology.
 近年、水道水から残留塩素(次亜塩素酸)、カビ臭、濁り、微生物等を除去することを目的とした小型浄水器が広く普及している。これらの浄水器には、水道水中の残留塩素、異味や異臭を取り除く活性炭、セラミックフィルタや、濁質や微生物を取り除く精密濾過膜、中空糸膜等が用いられていた。このような浄水器を住居等に設ける場合、台所の蛇口やシンク下に設置されることが多く、水道水を飲用や調理用に適するように浄化していた。 In recent years, small water purifiers for the purpose of removing residual chlorine (hypochlorous acid), musty odor, turbidity, microorganisms and the like from tap water have become widespread. In these water purifiers, residual chlorine in tap water, activated carbon that removes off-flavors and odors, ceramic filters, microfiltration membranes that remove turbidity and microorganisms, hollow fiber membranes, and the like were used. When such a water purifier is provided in a residence or the like, it is often installed under a kitchen faucet or sink, and tap water has been purified to be suitable for drinking and cooking.
 一方で、ビルやホテルなどの建物内の全域で浄化した水道水を使用したい、あるいは井戸水を浄化して建物内の全域で使用したいといったニーズが存在したが、全ての浄水の使用場所にそれぞれ浄水器を設置するのは煩雑である。そこで、建物へ水道水等を導入する入口に大型の浄水装置を取り付けて、水道水をまとめて浄化して建物全体に給水する浄水システムも普及し始めている。これらの大型浄水装置も、小型浄水器と同様に活性炭、セラミックフィルタ、精密濾過膜などで構成され、これらを通過させることにより水道水中の残留塩素や濁質等を取り除き、建物内にある複数の浄水の使用場所へ浄水を供給する。なお、本発明において、このような大型浄水装置をセントラル浄水装置と称する場合がある。 On the other hand, there was a need to use purified tap water in the entire area of buildings such as buildings and hotels, or to purify well water and use it in the entire area of the building. Installing the vessel is cumbersome. Therefore, a water purification system that attaches a large water purification device to an entrance for introducing tap water or the like into a building, purifies the tap water collectively, and supplies the entire building to water has begun to spread. These large water purifiers are also composed of activated carbon, ceramic filters, microfiltration membranes, etc., just like small water purifiers. By passing these, residual chlorine and turbidity in tap water are removed, and a plurality of water purifiers in the building are removed. Supply purified water to the place where it is used. In the present invention, such a large water purifier may be referred to as a central water purifier.
 このような大型浄水装置に関するものとしては、膜モジュールを使用する濾過装置が知られている(例えば、特許文献1~3)。特許文献1には、複数の膜モジュールと、前記膜モジュールそれぞれの1次側に原液を導入する導入ラインと、前記膜モジュールそれぞれの2次側に接続されると共に、前記膜モジュールによって濾過された濾過液を排出する濾過液排出ラインと、を備え、逆洗時には、逆洗対象となる前記膜モジュールに連絡する前記導入ラインの流路は閉鎖される濾過装置において、前記導入ラインに設けられると共に、所定流量の原液を前記膜モジュールに供給する原液供給ポンプと、前記濾過液排出ラインに設けられると共に、前記濾過液を圧送する濾過液圧送ポンプと、前記濾過液排出ラインの前記濾過液圧送ポンプよりも下流側と前記膜モジュールそれぞれの2次側とを連絡すると共に、逆洗時に逆洗対象となる前記膜モジュールとの間で流路が開放されて前記濾過液が逆洗液として流動する逆洗ラインと、前記膜モジュールそれぞれの1次側に接続されると共に、逆洗時に逆洗対象となる前記膜モジュールからの流路が開放されて前記膜モジュールを透過した前記逆洗液が排出される洗浄液排出ラインと、前記濾過液圧送ポンプの吸い込み側における前記濾過液の圧力を検出する圧検出手段と、前記圧検出手段で検出された圧力に基づいて前記濾過液圧送ポンプの駆動を制御する制御手段と、を備えたことを特徴とする濾過装置が開示されている。 As such a large water purification apparatus, a filtration apparatus using a membrane module is known (for example, Patent Documents 1 to 3). In Patent Document 1, a plurality of membrane modules, an introduction line for introducing a stock solution to the primary side of each of the membrane modules, and a secondary side of each of the membrane modules are connected and filtered by the membrane module. A filtration liquid discharge line for discharging the filtrate, and at the time of backwashing, the flow path of the introduction line communicating with the membrane module to be backwashed is provided in the introduction line in a filtration device that is closed A filtrate supply pump for supplying a filtrate at a predetermined flow rate to the membrane module; a filtrate pump for pumping the filtrate while being provided in the filtrate discharge line; and a filtrate pump for the filtrate discharge line And a flow path between the downstream side of the membrane module and the secondary side of each of the membrane modules, and the membrane module to be backwashed during backwashing. The flow path from the membrane module to be backwashed during backwashing is opened and connected to the primary side of each of the membrane modules and the backwash line through which the filtrate flows as backwashing liquid. A cleaning liquid discharge line through which the backwash liquid that has passed through the membrane module is discharged, pressure detection means for detecting the pressure of the filtrate on the suction side of the filtrate pressure feed pump, and detected by the pressure detection means And a control means for controlling the drive of the filtrate pumping pump based on the pressure.
 特許文献2には、透過水ラインを共通とした複数の膜モジュールを備えてなる膜分離装置の運転方法において、一部の膜モジュールにて逆洗を行うときに他の膜モジュールの透過水をその吐出圧によって逆洗対象膜モジュールの二次側に供給し、次いでこの二次側に加圧気体を供給することを特徴とする膜分離装置の運転方法が開示されている。 In Patent Document 2, in a method of operating a membrane separation apparatus having a plurality of membrane modules having a common permeate line, the permeate from other membrane modules is used when backwashing is performed in some membrane modules. There is disclosed a method of operating a membrane separation device, characterized in that it is supplied to the secondary side of the membrane module to be backwashed by the discharge pressure and then pressurized gas is supplied to the secondary side.
 特許文献3には、複数の膜モジュールを備える膜濾過装置において、逆洗を行う膜モジュールに、他の膜モジュールから得られる膜透過水を直接通液して逆洗するように通液路を切り替える通液路切替機構と、各膜モジュールに加圧空気を供給するためのコンプレッサ及び空気配管とを備え、逆洗を行う膜モジュールへの原水の導入を停止し、代りにコンプレッサからの加圧空気を該逆洗を行う膜モジュールの1次側に導入すると共に、他の膜モジュールの透過水を該逆洗を行う膜モジュールの2次側に導入して逆洗を行うか、或いは、逆洗を行う膜モジュールの2次側に加圧空気を供給し、逆洗水中に混合して気液混合流体で逆洗を行うように構成されている膜濾過装置であって、原水槽に原水主配管が接続され、この原水主配管から原水枝配管が分岐しており、各原水枝配管の末端側が各膜モジュールの原水導入口に接続され、各原水枝配管に開閉バルブが設けられ、各膜モジュールの濃縮水流出口は、配管を介して三方バルブの流入ポートに接続され、該三方バルブはそれぞれ2個の流出ポートを備えており、そのうちの一方の流出ポートにそれぞれ濃縮水循環用の枝配管が接続され、これらの濃縮水枝配管は濃縮水主配管に接続されており、前記三方バルブの他方の流出ポートにはそれぞれ逆洗排水排出用の枝配管の一端が接続され、該枝配管の他端は逆洗排水排出用の主配管に接続されており、前記膜モジュールの透過水流出口には、それぞれ透過水取出用の枝配管の一端が接続されており、該枝配管の他端は透過水取出用の主配管に接続されており、前記原水枝配管の各開閉バルブと各膜モジュールとの間の部分に対し空気枝配管の末端側が接続され、各空気枝配管の上流端側は空気主配管に接続され、この空気主配管はコンプレッサに接続されていることを特徴とする膜濾過装置が開示されている。 Patent Document 3 discloses that in a membrane filtration apparatus including a plurality of membrane modules, a membrane passage that performs backwashing is directly passed with membrane permeated water obtained from another membrane module and backwashed. Equipped with a fluid passage switching mechanism for switching, a compressor and air piping for supplying pressurized air to each membrane module, stops the introduction of raw water into the membrane module performing backwashing, and instead pressurizes from the compressor Introduce air to the primary side of the membrane module for backwashing and introduce permeated water from other membrane modules to the secondary side of the membrane module for backwashing to perform backwashing or backwashing. A membrane filtration device configured to supply pressurized air to the secondary side of a membrane module that performs washing, mix in backwash water, and backwash with a gas-liquid mixed fluid. The main pipe is connected, and the raw water main pipe Branch pipes are branched, the end side of each raw water branch pipe is connected to the raw water inlet of each membrane module, each raw water branch pipe is provided with an open / close valve, and the concentrated water outlet of each membrane module is connected via the pipe The three-way valve is connected to an inflow port of the three-way valve, and each of the three-way valves has two outflow ports. One of the outflow ports is connected to a branch pipe for circulating the concentrated water. Connected to the main pipe, one end of the branch pipe for backwash drainage is connected to the other outflow port of the three-way valve, and the other end of the branch pipe is connected to the main pipe for backwash drainage discharge One end of a branch pipe for extracting permeate is connected to the permeate outlet of the membrane module, and the other end of the branch pipe is connected to a main pipe for extracting permeate, Raw water branch piping The end side of the air branch pipe is connected to the portion between each on-off valve and each membrane module, the upstream end side of each air branch pipe is connected to the air main pipe, and this air main pipe is connected to the compressor. A membrane filtration device characterized by this is disclosed.
 浄水装置が採取する原水の種類によっては、重金属、ヒ素、フッ素などの不純物質の含有率が異なる場合があり、不純物質を効率的に除去する必要がある。不純物質を除去する方法として、凝集剤を用いて不純物質を凝集させて沈殿、分離する方法が知られている。例えば、特許文献4には、凝集剤を添加してフロックを形成した被処理水を膜モジュールで濾過する凝集濾過処理装置であって、上記被処理水に凝集剤を添加する添加部が設けられ、上記添加部の下流側に凝集剤を添加した被処理水を撹拌する撹拌装置が設けられ、上記撹拌装置の下流側に上記膜モジュールが設けられていることを特徴とする凝集濾過処理装置が開示されている。 Depending on the type of raw water collected by the water purification device, the content of impurities such as heavy metals, arsenic, and fluorine may differ, and it is necessary to efficiently remove impurities. As a method for removing impurities, there is known a method in which impurities are aggregated by using a flocculant to precipitate and separate. For example, Patent Document 4 is a coagulation filtration apparatus for filtering water to be treated, which has flocs formed by adding a flocculant, with a membrane module, and is provided with an addition unit for adding the flocculant to the water to be treated. An aggregating and filtering apparatus comprising: a stirrer that stirs water to be treated with a flocculant added downstream of the adding unit; and the membrane module that is disposed downstream of the agitator. It is disclosed.
 水酸化第二鉄コロイドを使用する水処理方法が知られている。例えば、特許文献5には、処理対象とする水へ第1鉄塩水溶液と正に帯電した水酸化第二鉄コロイド溶液を加えて撹拌し、次に当該水のpHを6~8に調整することにより水に溶解または分散する有機物質または無機物質を沈殿除去と多孔性膜によって除去することを特徴とする水の浄化方法が開示されている。特許文献6には、フェノール類を溶解したCODの高い排水のCODを減少させる排水処理方法において、酸化状態下において(1)塩化第1鉄水溶液あるいは塩化第2鉄水溶液、あるいは塩化第1鉄と塩化第2鉄とを混合した水溶液、あるいは平均粒径4nm以上で30nm未満の水酸化第2鉄コロイドの水溶液を加えるか、あるいは鉄を陽極として該排水に電気分解を行うことによって鉄イオンを発生させた後に、(2)当該排水のpHを5以上9未満にアルカリ水溶液または酸水溶液を混入させることにより調整し、(3)生じた沈殿物を除去後、(4)平均粒径10nm以上で20nm未満の水酸化第2鉄コロイド水溶液を添加し、沈殿物を除去することを特徴とする排水の処理方法が開示されている。 A water treatment method using ferric hydroxide colloid is known. For example, in Patent Document 5, a ferrous salt aqueous solution and a positively charged ferric hydroxide colloid solution are added to water to be treated and stirred, and then the pH of the water is adjusted to 6-8. Thus, a water purification method is disclosed, in which an organic substance or an inorganic substance dissolved or dispersed in water is removed by precipitation and a porous membrane. In Patent Document 6, in a wastewater treatment method for reducing COD of wastewater with high COD in which phenols are dissolved, (1) ferrous chloride aqueous solution, ferric chloride aqueous solution, or ferrous chloride in an oxidized state An aqueous solution mixed with ferric chloride or an aqueous solution of ferric hydroxide colloid having an average particle size of 4 nm or more and less than 30 nm is added, or iron is generated by electrolysis of the waste water using iron as an anode. (2) The pH of the waste water is adjusted by mixing an alkaline aqueous solution or an aqueous acid solution to 5 or more and less than 9, and (3) after removing the generated precipitate, (4) with an average particle size of 10 nm or more Disclosed is a method for treating waste water, which comprises adding a ferric hydroxide colloid aqueous solution of less than 20 nm to remove precipitates.
特開2011-177653号公報JP 2011-177653 A 特開2001-190935号公報JP 2001-190935 A 特許第4178178号公報Japanese Patent No. 4178178 特開2004-267842号公報JP 2004-267842 A 特開2010-247057号公報JP 2010-247057 A 特開2012-196657号公報JP 2012-196657 A
 濾過手段として膜モジュールを使用した濾過装置において、凝集剤を添加し、凝集物を沈殿、除去する方法では、凝集沈殿槽が必要となるため、装置が大型化するという問題がある。しかしながら、ビルやホテルなどの建物に濾過装置を設置するためには、濾過装置を小型化することが求められている。また、濾過手段として膜モジュールを使用する濾過装置を継続的に使用していると、膜モジュールが備える濾過膜に異物が目詰まりして、濾過効率が低下する。濾過装置の膜モジュールの濾過効率を低下させないためには、膜モジュールを逆洗浄する必要がある。しかし、従来の凝集剤を用いた場合には、凝集物が濾過膜の細孔を閉塞しやすく、頻繁に逆洗浄をする必要がある。特に、凝集沈殿層を設けない場合には、濾過膜の閉塞が顕著になり、原水の処理量が著しく低下するという問題がある。また、従来の凝集剤では、重金属イオンを含有する原水から、効率的に重金属イオンを除去できない。 In a filtration apparatus using a membrane module as a filtration means, a method of adding a flocculant and precipitating and removing agglomerates requires a coagulation sedimentation tank, which increases the size of the apparatus. However, in order to install a filtration device in a building such as a building or a hotel, it is required to reduce the size of the filtration device. Moreover, when the filtration apparatus which uses a membrane module as a filtration means is used continuously, a foreign material will clog the filtration membrane with which a membrane module is provided, and filtration efficiency will fall. In order not to lower the filtration efficiency of the membrane module of the filtration device, it is necessary to back-wash the membrane module. However, when a conventional flocculant is used, the agglomerates easily block the pores of the filtration membrane, and frequent backwashing is required. In particular, when the coagulation sedimentation layer is not provided, there is a problem that the filtration membrane becomes clogged and the amount of raw water treated is significantly reduced. In addition, conventional flocculants cannot efficiently remove heavy metal ions from raw water containing heavy metal ions.
 特許文献5、6には、水酸化第二鉄コロイドを用いて、多孔性膜を用いて孔拡散・濾過する水処理技術が開示されている。しかし、孔拡散・濾過法は、膜間差圧を0.3気圧以下でクロスフロー方式で濾過を行う方法であり、原水処理量能力が低い。また多孔性平膜を用いているために、原水処理量を多くするためには、装置が大型化するという問題がある。 Patent Documents 5 and 6 disclose a water treatment technique that uses ferric hydroxide colloid and diffuses and filters pores using a porous membrane. However, the pore diffusion / filtration method is a method of performing filtration by a cross flow method with a transmembrane pressure difference of 0.3 atm or less, and has a low raw water treatment capacity. Moreover, since the porous flat membrane is used, there is a problem that the apparatus becomes large in order to increase the raw water treatment amount.
 本発明は、前記事情に鑑みてなされたものであって、重金属イオン、ヒ素などの不純物質を効率的に除去する生活用浄水の製造方法および生活用浄水の製造装置を提供することを課題とする。また、本発明は、マンション、ビルなどの建物全域に生活用浄水を供給するセントラル浄水装置の小型化をさらなる課題とする。 This invention is made | formed in view of the said situation, Comprising: It aims at providing the manufacturing method of domestic water purification which removes impurities, such as heavy metal ion and arsenic efficiently, and the manufacturing apparatus of domestic water purification To do. Another object of the present invention is to reduce the size of a central water purification apparatus that supplies clean water for daily use to the entire building such as a condominium and a building.
 本発明の生活用浄水の製造方法は、原水に造核剤を添加し、膜手段で濾過する生活用浄水の製造方法であって、前記造核剤として、重量平均粒子径が5nm~160nmの水酸化第二鉄のコロイド粒子の水分散物を用いて、前記原水に添加される鉄分の総質量に対する水酸化第二鉄コロイド粒子水分散物の鉄分の質量の比率を0.9以上にすることを特徴とする。 The method for producing domestic water for purification according to the present invention is a method for producing domestic water for purification by adding a nucleating agent to raw water and filtering with a membrane means, wherein the nucleating agent has a weight average particle diameter of 5 nm to 160 nm. Using the aqueous dispersion of ferric hydroxide colloidal particles, the ratio of the iron mass of the aqueous ferric hydroxide colloidal particles to the total mass of iron added to the raw water is set to 0.9 or more. It is characterized by that.
 一般に市販されている凝集剤は、例えば、被処理水に浮遊する100μm~1μm程度のコロイド粒子を凝集させるのに適しているが、粒度の小さい重金属イオンなどのイオン物質やイオン分子を凝集させることは難しい。本発明者らは、重量平均粒子径が5nm~160nmの水酸化第二鉄のコロイド粒子の水分散物(以下、単に「水酸化第二鉄の水分散物」と称する場合がある)を用いれば、粒度が小さい重金属イオンなどのイオン物質やイオン分子を捕捉する効果が大きくなることを見出し、本発明を完成した。本発明で使用する重量平均粒子径が5nm~160nmの水酸化第二鉄のコロイド粒子の水分散物は、原水中に含まれるイオン性の不純物質を電位による電荷効果によって吸着し、コロイド粒子を中心として粒子が成長して粒度が大きくなる作用を有するものと考えられている。さらに、造核剤を中心とした粒子同士が凝集した凝集物を生成する場合もある。本発明ではこのような作用効果がある水酸化第二鉄のコロイド粒子の水分散物を「造核剤」と称し、一般の凝集剤と区別している。一般の凝集剤が、不純物を凝集し、凝集物を大きくし沈殿させて除去することを目的としているのに対し、本発明の生活用浄水の製造方法では、「造核剤」が形成した凝集物を沈殿させることなく、膜手段で直接濾過するところに特徴がある。本発明において、造核剤として重量平均粒子径が5nm~160nmの水酸化第二鉄のコロイド粒子の水分散物を用いれば、「造核剤」が形成する凝集物の粒度が制御されて、膜手段の閉塞を抑制する効果がある。その結果、ある程度の量の生活用浄水を安定して供給できる。 The commercially available flocculants are suitable for aggregating colloidal particles of about 100 μm to 1 μm floating in the water to be treated, for example, but agglomerate ionic substances and ionic molecules such as small metal ions. Is difficult. The present inventors used an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm (hereinafter sometimes simply referred to as “aqueous dispersion of ferric hydroxide”). For example, the inventors have found that the effect of capturing ionic substances and ion molecules such as heavy metal ions having a small particle size is increased, and the present invention has been completed. The aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm used in the present invention adsorbs ionic impurities contained in the raw water by the charge effect due to the potential, It is considered that the particle grows as the center and has an effect of increasing the particle size. Furthermore, an aggregate in which particles centering on a nucleating agent are aggregated may be generated. In the present invention, an aqueous dispersion of ferric hydroxide colloidal particles having such an effect is called a “nucleating agent” and is distinguished from a general flocculant. The general flocculant is intended to agglomerate impurities, to enlarge and precipitate the aggregate, and to remove it, in the method for producing purified water for daily use of the present invention, the flocculating agent formed by the “nucleating agent” It is characterized in that it is filtered directly by membrane means without precipitating the product. In the present invention, if an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm is used as the nucleating agent, the particle size of the aggregate formed by the “nucleating agent” is controlled, There is an effect of suppressing the blockage of the membrane means. As a result, a certain amount of clean water for daily use can be stably supplied.
 本発明の生活用浄水の製造方法に使用される装置は、原水供給路と、原水供給路に配置され、原水を送液する原水供給手段と、前記原水供給路を少なくとも2以上に分岐する複数の原水分岐路と、前記複数の原水分岐路に配置され、原水を濾過する複数の膜手段を備える膜モジュールと、前記複数の膜モジュールの一次側に接続する排出路と、前記複数の膜モジュールの二次側に接続する複数の浄水分岐路と、前記複数の浄水分岐路が合流する浄水路とを有しており、前記膜モジュールの一次側で、原水に造核剤を供給する手段を備え、造核剤の添加によって発生する凝集物を沈殿させて分離する分離槽を備えないことを特徴とする。 The apparatus used in the method for producing domestic purified water according to the present invention includes a raw water supply channel, a raw water supply unit that is disposed in the raw water supply channel, and feeds the raw water, and a plurality of branching the raw water supply channel into at least two or more. A raw water branch path, a membrane module that is arranged in the plurality of raw water branch paths and includes a plurality of membrane means for filtering raw water, a discharge path that is connected to a primary side of the plurality of membrane modules, and the plurality of membrane modules Means for supplying a nucleating agent to the raw water on the primary side of the membrane module. And a separation tank that precipitates and separates agglomerates generated by the addition of a nucleating agent.
 本発明によれば、重金属イオンおよびヒ素などのイオン性不純物質を効率的に除去した生活用浄水を提供することができる。また、本発明によれば、逆洗浄効率が高い浄水装置が得られる。本発明の浄水装置は、小型化が可能である。 According to the present invention, it is possible to provide clean water for daily use from which ionic impurities such as heavy metal ions and arsenic are efficiently removed. Moreover, according to this invention, the water purifier with high backwashing efficiency is obtained. The water purifier of the present invention can be reduced in size.
水酸化第二鉄コロイド粒子を模式的に説明する説明図である。It is explanatory drawing which illustrates a ferric hydroxide colloid particle typically. 水酸化第二鉄コロイド粒子を模式的に説明する説明図である。It is explanatory drawing which illustrates a ferric hydroxide colloid particle typically. 重金属イオンを捕捉する態様を模式的に説明する説明図である。It is explanatory drawing which illustrates the aspect which capture | acquires a heavy metal ion typically. 造核した粒子同士が凝集する態様を模式的に説明する説明図である。It is explanatory drawing which illustrates typically the aspect which nucleated particle | grains aggregate. 本発明の一実施形態の浄水製造装置を模式的に示す図である。It is a figure which shows typically the purified water manufacturing apparatus of one Embodiment of this invention. 実施形態の浄水装置の浄水製造工程の通水状態を示す図である。It is a figure which shows the water flow state of the purified water manufacturing process of the purified water apparatus of embodiment. 実施形態の浄水装置の逆洗工程の通水状態を示す図である。It is a figure which shows the water flow state of the backwashing process of the water purifier of embodiment. 実施形態の浄水装置の逆洗工程の通水状態を示す図である。It is a figure which shows the water flow state of the backwashing process of the water purifier of embodiment. 濾過処理前後の処理水中のCd濃度変化を示すグラフである。It is a graph which shows Cd density | concentration change in the treated water before and behind a filtration process. Cd除去負荷量指数を示すグラフである。It is a graph which shows a Cd removal load amount index | exponent. 濾過処理前後の処理水のAs濃度変化を示すグラフである。It is a graph which shows the As density | concentration change of the treated water before and behind a filtration process. As除去負荷量指数を示すグラフである。It is a graph which shows an As removal load amount index. 濾過処理後のAs濃度のpH依存性を示すグラフである。It is a graph which shows the pH dependence of As concentration after a filtration process. 濾過処理後のPb濃度のpH依存性を示すグラフである。It is a graph which shows the pH dependence of Pb density | concentration after a filtration process. 平均粒子径と除去率との関係を示すグラフである。It is a graph which shows the relationship between an average particle diameter and a removal rate.
(1)生活用浄水の製造方法
 本発明の生活用浄水の製造方法は、原水に造核剤を添加し、膜手段で濾過する生活用浄水の製造方法であって、前記造核剤として、重量平均粒子径が5nm~160nmの水酸化第二鉄のコロイド粒子の水分散物を用いて、前記原水に添加される鉄分の総質量に対する水酸化第二鉄コロイド粒子水分散物の鉄分の質量の比率を0.9以上にすることを特徴とする。本発明によれば、原水中に含まれる粒度が小さい重金属イオンなどのイオン性不純物質は、造核剤に捕捉されて、効率的に除去される。
(1) Manufacturing method of domestic water purification The manufacturing method of domestic water purification of this invention is a manufacturing method of domestic water purification which adds a nucleating agent to raw | natural water and filters with a membrane means, As said nucleating agent, Using an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm, the mass of iron in the aqueous dispersion of ferric hydroxide colloidal particles relative to the total mass of iron added to the raw water The ratio is made 0.9 or more. According to the present invention, ionic impurities such as heavy metal ions having a small particle size contained in the raw water are captured by the nucleating agent and efficiently removed.
 まず、本発明の生活用浄水の製造方法の処理対象になる原水について説明する。前記原水としては、自然水または水道水を挙げることができる。自然水とは、井戸水、地下水、雨水、河川、池、湖などの自然界に存在する淡水である。水道水とは、水浄化施設から供給される浄化された水である。本発明で処理対象とする原水には、工業用排水、産業用排水などは含まない。工業用排水や産業用排水は、不純物質の種類が多く、また不純物質の濃度が高い為、本発明によっても不純物質を除去しきれず生活用浄水としては許容できないからである。 First, raw water to be treated by the method for producing water for daily life of the present invention will be described. Examples of the raw water include natural water or tap water. Natural water is fresh water that exists in the natural world such as well water, groundwater, rainwater, rivers, ponds, and lakes. Tap water is purified water supplied from a water purification facility. The raw water to be treated in the present invention does not include industrial wastewater, industrial wastewater and the like. This is because industrial wastewater and industrial wastewater have many types of impurities and have a high concentration of impurities, so that the impurities cannot be removed even by the present invention and are not acceptable as clean water for daily use.
 また、本発明によれば、原水に含まれるイオン性不純物質を除去することができる。原水に含まれるイオン性不純物質としては、鉄(Fe2+、Fe3+)、カドミウム(Cd2+)、銅(Cu2+)、鉛(Pb2+)、ヒ素(AsO 3-など)などの重金属イオン、アルミニウム(Al3+)などの金属イオンを除去することができる。本発明によれば、陰イオン性不純物質および陽イオン性不純物質のいずれも除去することができる。 Moreover, according to this invention, the ionic impurity contained in raw | natural water can be removed. The ionic impurities contained in the raw water include heavy metal ions such as iron (Fe 2+ , Fe 3+ ), cadmium (Cd 2+ ), copper (Cu 2+ ), lead (Pb 2+ ), arsenic (AsO 4 3−, etc.) Metal ions such as aluminum (Al 3+ ) can be removed. According to the present invention, both anionic impurities and cationic impurities can be removed.
 次に、本発明において、造核剤として使用する重量平均粒子径が5nm~160nmの水酸化第二鉄コロイド粒子水分散物について説明する。本発明で使用する重量平均粒子径が5nm~160nmの水酸化第二鉄コロイド粒子水分散物は、原水中に含まれるイオン性不純物質を電位による電荷効果によって吸着し、コロイド粒子を中心として粒子が成長し、粒度が大きくなるものと考えられている。さらに、造核剤を中心とする成長した粒子同士が凝集して、凝集物を形成する場合もある。本発明では、造核剤として、重量平均粒子径が5nm~160nmの水酸化第二鉄コロイド粒子水分散物を用いることにより、原水に含まれる粒度が小さいイオン性不純物質(重金属イオン、ヒ素、フッ素などのイオン性物質)を効率的に捕捉できる。また、成長した造核剤粒子、および、これらが凝集した凝集物の粒度を制御するという観点からも、造核剤の重量平均粒子径は、5nm~160nmに制御されていることが好ましい。重量平均粒子径が5nm~160nmの造核剤を用いることにより、凝集物による膜手段の閉塞が抑制されると考えられる。 Next, an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm used as a nucleating agent in the present invention will be described. The aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of 5 nm to 160 nm used in the present invention adsorbs ionic impurities contained in the raw water by the charge effect due to electric potential, and the particles are mainly composed of colloidal particles. Are believed to grow and become larger in particle size. Furthermore, the grown particles centering on the nucleating agent may aggregate to form an aggregate. In the present invention, by using a ferric hydroxide colloid particle aqueous dispersion having a weight average particle size of 5 nm to 160 nm as a nucleating agent, an ionic impurity having a small particle size contained in raw water (heavy metal ions, arsenic, Ionic substances such as fluorine) can be efficiently captured. From the viewpoint of controlling the particle size of the grown nucleating agent particles and the aggregates of these nucleating agents, the weight average particle size of the nucleating agent is preferably controlled to 5 nm to 160 nm. By using a nucleating agent having a weight average particle diameter of 5 nm to 160 nm, it is considered that clogging of the membrane means by aggregates is suppressed.
 前記水酸化第二鉄の水分散物の重量平均粒子径は、10nm以上がより好ましく、15nm以上がさらに好ましく、50nm以下が好ましく、40nm以下がより好ましく、25nm以下がさらに好ましい。重量平均粒子径が小さくなりすぎると、水酸化第二鉄の水分散物が、膜手段を透過する可能性がある。また、重量平均粒子径が大きくなりすぎると、ヒ素や重金属などのイオン分子を捕捉する効果が小さくなる。本発明において、水酸化第二鉄の水分散物の重量平均粒子径は、例えば、大塚電子(株)製のDLS-8000/6500を用いて、動的光散乱法により測定する。 The weight average particle size of the aqueous dispersion of ferric hydroxide is more preferably 10 nm or more, further preferably 15 nm or more, preferably 50 nm or less, more preferably 40 nm or less, and further preferably 25 nm or less. If the weight average particle size becomes too small, the aqueous dispersion of ferric hydroxide may permeate the membrane means. Moreover, when the weight average particle diameter becomes too large, the effect of capturing ionic molecules such as arsenic and heavy metals is reduced. In the present invention, the weight average particle size of the aqueous dispersion of ferric hydroxide is measured by a dynamic light scattering method using, for example, DLS-8000 / 6500 manufactured by Otsuka Electronics Co., Ltd.
 前記水酸化第二鉄コロイド粒子水分散物としては、例えば、正に帯電した第二鉄イオン粒子の外側を、負に帯電した対イオンが吸着してなるコロイド粒子が、水に分散したものを挙げることができる。対イオンとしては、硫酸イオン、水酸化物イオン、塩素イオンなどを挙げることができる。 As the ferric hydroxide colloidal particle aqueous dispersion, for example, a colloidal particle formed by adsorbing a negatively charged counterion on the outside of a positively charged ferric ion particle is dispersed in water. Can be mentioned. Examples of the counter ion include sulfate ion, hydroxide ion, and chlorine ion.
 図1は、造核剤として使用する水酸化第二鉄コロイド粒子100を模式的に説明する説明図である。正に帯電した鉄イオン(Fe3+)からなる核101の表面に対イオンである水酸化物イオン(OH)からなる層102が形成されている。水酸化第二鉄コロイド粒子100は、鉄イオンからなる核101の外側に水酸化物イオンからなる層102が形成されているために、水との親和性が高く、水中での安定性が高い。また、この水酸化第二鉄コロイド粒子を中心として、成長用の鉄イオン(Fe3+)を加えることにより、図2に示した様に、鉄イオン(Fe3+)からなる層103と、水酸化物イオン(OH)からなる層104とが交互に形成され、粒子径が大きくなる。 FIG. 1 is an explanatory view schematically illustrating ferric hydroxide colloidal particles 100 used as a nucleating agent. A layer 102 made of hydroxide ions (OH ) as counter ions is formed on the surface of the nucleus 101 made of positively charged iron ions (Fe 3+ ). The ferric hydroxide colloidal particles 100 have a high affinity with water and a high stability in water because the layer 102 made of hydroxide ions is formed outside the core 101 made of iron ions. . Further, by adding iron ions (Fe 3+ ) for growth around the ferric hydroxide colloidal particles, as shown in FIG. 2, a layer 103 made of iron ions (Fe 3+ ), Layers 104 made of hydroxide ions (OH ) are alternately formed, and the particle diameter is increased.
 図3は、造核剤である水酸化第二鉄コロイド粒子が、重金属イオン(X-)を捕捉する態様を模式的に説明する説明図である。正に帯電した鉄イオン(Fe3+)からなる核101の表面には、対イオンである水酸化物イオン(OH)からなる層102が形成されている。水酸化物イオン(OH)からなる層102は負に帯電しているため、造核剤や原水に含まれる陽イオン(M+)や水素イオン(H+)を引き付ける。その結果、正に帯電した陽イオンからなる層105が、水酸化物イオンからなる層102の外側に形成される。同様の作用により、陽イオンからなる層105は、重金属イオン(X)や水酸化物イオン(OH)を引き付け、陽イオンからなる層105の外側には、陰イオンからなる層106が形成される。なお、鉄イオンからなる核101から離れるにつれて、電位による電荷効果が弱くなる。そのため、外側の層では正負のイオンが混在しやすくなる。このように、造核剤は、金属イオンの核を中心として、対イオンを吸着することにより、粒子が成長する。その際、原水中のイオン性不純物質を粒子内部に捕捉する。図4は、造核した粒子同士が凝集して、さらなる凝集物を形成する態様を示した。 FIG. 3 is an explanatory view schematically illustrating an aspect in which ferric hydroxide colloidal particles, which are nucleating agents, capture heavy metal ions (X ). On the surface of the nucleus 101 made of positively charged iron ions (Fe 3+ ), a layer 102 made of hydroxide ions (OH ) as counter ions is formed. Since the layer 102 of hydroxide ions (OH ) is negatively charged, it attracts cations (M + ) and hydrogen ions (H + ) contained in the nucleating agent and raw water. As a result, a layer 105 made of positively charged cations is formed outside the layer 102 made of hydroxide ions. By the same action, the layer 105 made of cations attracts heavy metal ions (X ) and hydroxide ions (OH ), and the layer 106 made of anions is formed outside the layer 105 made of cations. Is done. In addition, the electric charge effect by an electric potential becomes weak as it leaves | separates from the nucleus 101 which consists of iron ions. Therefore, positive and negative ions are likely to be mixed in the outer layer. As described above, the nucleating agent grows particles by adsorbing the counter ion around the core of the metal ion. At that time, ionic impurities in the raw water are trapped inside the particles. FIG. 4 shows a mode in which nucleated particles aggregate to form further aggregates.
 前記水酸化第二鉄コロイド粒子水分散物は、例えば、塩化第二鉄に水酸化ナトリウムを加えて、pHを約2.7になるように調整して、加熱することにより作製することができる。平均粒子径は、3価鉄イオンと水酸化物イオン、あるいは、コロイド粒子の成長用に加える鉄イオンの量などにより制御することができる。また、前記水酸化第二鉄のコロイド粒子の水分散物は、pHが1.5~4.0に調整されていることが好ましい。pHが高くなると、水酸化第二鉄コロイドの安定性が低下する場合があるからである。なお、前記水酸化第二鉄のコロイド粒子の水分散物に塩化第二鉄由来等の鉄イオンが含まれると、造核剤によって原水から発生する凝集物の大きさが大きくなって膜手段を閉塞しやすくなるので、塩化第二鉄と水酸化ナトリウムの量を調整することにより、前記水酸化第二鉄のコロイド粒子の水分散物に塩化第二鉄由来等の鉄イオンは含まれていないようにするのがよい。 The aqueous ferric hydroxide colloidal particle dispersion can be prepared, for example, by adding sodium hydroxide to ferric chloride and adjusting the pH to about 2.7 and heating. . The average particle diameter can be controlled by the amount of iron ions added for the growth of trivalent iron ions and hydroxide ions or colloidal particles. The aqueous dispersion of ferric hydroxide colloidal particles preferably has a pH adjusted to 1.5 to 4.0. This is because as the pH increases, the stability of the ferric hydroxide colloid may decrease. If the ferric hydroxide colloidal particle aqueous dispersion contains ferric chloride or other iron ions, the size of the aggregates generated from the raw water by the nucleating agent increases, and the membrane means is used. Since it becomes easy to block, by adjusting the amount of ferric chloride and sodium hydroxide, the aqueous dispersion of ferric hydroxide colloidal particles does not contain ferric chloride-derived iron ions. It is better to do so.
 造核剤として使用する水酸化第二鉄コロイド粒子の水分散物(原水に添加する為にあらかじめ製造しておく造核剤の水分散物)の全鉄濃度は、造核剤の運搬性および運搬コストを考慮すると高濃度が好ましい。即ち、全鉄濃度は、1,000mg/L以上が好ましく、3,000mg/L以上がより好ましく、4,000mg/L以上がさらに好ましい。但し、10,000mg/L超では、自己凝集し沈殿物を生じることから、10,000mg/L以下が好ましく、8,000mg/L以下がより好ましく、6,000mg/L以下がさらに好ましい。なお、全鉄濃度は、水酸化第二鉄コロイド粒子の水分散物1Lに含まれる鉄分(Fe)の総質量(mg)である。全鉄濃度はICP質量分析法にて測定する。 The total iron concentration of the aqueous dispersion of ferric hydroxide colloidal particles used as a nucleating agent (an aqueous dispersion of a nucleating agent prepared in advance for addition to raw water) is determined by the transportability of the nucleating agent and Considering the transportation cost, a high concentration is preferable. That is, the total iron concentration is preferably 1,000 mg / L or more, more preferably 3,000 mg / L or more, and further preferably 4,000 mg / L or more. However, if it exceeds 10,000 mg / L, it is self-aggregated to produce a precipitate, so that it is preferably 10,000 mg / L or less, more preferably 8,000 mg / L or less, and even more preferably 6,000 mg / L or less. The total iron concentration is the total mass (mg) of iron (Fe) contained in 1 L of the aqueous dispersion of ferric hydroxide colloid particles. Total iron concentration is measured by ICP mass spectrometry.
 原水に造核剤を添加する態様としては、例えば、原水槽に貯蔵した原水に造核剤を添加する態様、膜手段に原水を供給する原水供給路で、原水に造核剤を添加する態様などを挙げることができる。造核剤によって形成される凝集物の粒度を制御するという観点からは、膜手段の直前で原水に造核剤を添加することが好ましい。凝集物の粒度が大きくなりすぎると、凝集物が膜手段の細孔を閉塞する場合がある。なお、原水に造核剤を添加する態様では、発生する凝集物を沈降・分離させることなく、そのまま膜手段で濾過することが好ましい。 As an aspect of adding the nucleating agent to the raw water, for example, an aspect of adding the nucleating agent to the raw water stored in the raw water tank, an aspect of adding the nucleating agent to the raw water in the raw water supply path for supplying the raw water to the membrane means And so on. From the viewpoint of controlling the particle size of the aggregate formed by the nucleating agent, it is preferable to add the nucleating agent to the raw water immediately before the membrane means. If the aggregate particle size becomes too large, the aggregate may block the pores of the membrane means. In addition, in the aspect which adds a nucleating agent to raw | natural water, it is preferable to filter with a membrane means as it is, without settling and isolate | separating the generated aggregate.
 原水に対する造核剤(水酸化第二鉄コロイド粒子の水分散物)の添加量は、高濃度であるほど除去効果を発揮することから、全鉄濃度で0.05mg/L以上が好ましく、0.3mg/L以上がより好ましく、0.5mg/L以上がさらに好ましい。また、原水に対する造核剤の添加量は、全鉄濃度で、9mg/L以下が好ましく、6mg/L以下がより好ましく、4mg/L以下がさらに好ましい。9mg/L以下であれば、製造コストの低減や造核剤用タンクの小型化を図ることができる。なお、不純物質の含有率が低い原水(例えば、水道水)の場合、コスト低減という観点から、原水に対する造核剤濃度の上限は、3mg/Lが好ましく、2mg/Lがより好ましく、1mg/Lがさらに好ましい。造核剤の添加量は、原水1Lに対して加える造核剤(水酸化第二鉄コロイド粒子の水分散物)の鉄成分(Fe)の総質量(mg)で表される。 The amount of nucleating agent (aqueous dispersion of ferric hydroxide colloidal particles) added to the raw water exhibits a removal effect as the concentration increases, so that the total iron concentration is preferably 0.05 mg / L or more, 0 .3 mg / L or more is more preferable, and 0.5 mg / L or more is more preferable. The amount of the nucleating agent added to the raw water is preferably 9 mg / L or less, more preferably 6 mg / L or less, and further preferably 4 mg / L or less in terms of total iron concentration. If it is 9 mg / L or less, the manufacturing cost can be reduced and the nucleating agent tank can be downsized. In the case of raw water (for example, tap water) having a low impurity content, the upper limit of the nucleating agent concentration relative to the raw water is preferably 3 mg / L, more preferably 2 mg / L, from the viewpoint of cost reduction. L is more preferable. The addition amount of the nucleating agent is represented by the total mass (mg) of the iron component (Fe) of the nucleating agent (aqueous dispersion of ferric hydroxide colloid particles) added to 1 L of raw water.
 本発明では、原水に添加される鉄分の総質量に対する水酸化第二鉄コロイド粒子の水分散物に含有される鉄分の質量の比率を0.9以上にする。すなわち、原水に水酸化第二鉄コロイド粒子の水分散物以外の鉄分含有水性液を添加する場合、水酸化第二鉄コロイド粒子の水分散物に含まれる鉄分の質量をAとし、水酸化第二鉄コロイド粒子の水分散物以外の鉄分含有水性液に含まれる鉄分の質量をBとしたときに、原水に添加される鉄分の総質量(A+B)に対する水酸化第二鉄コロイド粒子の水分散物に含有される鉄分Aの質量の比率(A/(A+B))を0.9以上にすることが好ましく、0.95以上にすることがより好ましく、0.99以上にすることがさらに好ましい。(A/(A+B))の比率を1に近づけることによって、膜手段の閉塞を抑止でき、浄水コストを低減できる。ここで、水酸化第二鉄コロイド粒子の水分散物(原水に添加する為にあらかじめ製造しておく造核剤の水分散物)の鉄分には、例えば、コロイド粒子自体の鉄分や、コロイド粒子の原料となる塩化第二鉄に由来する鉄分が含まれる。また、水酸化第二鉄コロイド粒子の水分散物以外の鉄分含有水性液としては、例えば、塩化第一鉄水溶液や塩化第二鉄水溶液などを挙げることができる。なお、鉄分含有水性液に含有される鉄分は、コロイド粒子に吸着して造核剤の粒度を大きくする場合がある。このような効果を優先する場合には、(A/(A+B))の値を0.99以下にしてもよく、さらに0.98以下としてもよい。なお、鉄濃度はICP質量分析法にて測定する。 In the present invention, the ratio of the mass of iron contained in the aqueous dispersion of ferric hydroxide colloid particles to the total mass of iron added to the raw water is set to 0.9 or more. That is, when an iron-containing aqueous liquid other than the aqueous dispersion of ferric hydroxide colloid particles is added to the raw water, the mass of iron contained in the aqueous dispersion of ferric hydroxide colloid particles is A, Aqueous dispersion of ferric hydroxide colloidal particles relative to the total mass of iron added to the raw water (A + B), where B is the mass of iron contained in the iron-containing aqueous liquid other than the aqueous dispersion of ferric colloidal particles The mass ratio (A / (A + B)) of iron A contained in the product is preferably 0.9 or more, more preferably 0.95 or more, and even more preferably 0.99 or more. . By making the ratio of (A / (A + B)) close to 1, blockage of the membrane means can be suppressed and water purification costs can be reduced. Here, the iron content of the aqueous dispersion of ferric hydroxide colloidal particles (the aqueous dispersion of the nucleating agent prepared in advance for addition to the raw water) includes, for example, the iron content of the colloidal particles themselves and the colloidal particles. The iron content derived from ferric chloride used as a raw material is included. Examples of the iron-containing aqueous liquid other than the aqueous dispersion of ferric hydroxide colloidal particles include a ferrous chloride aqueous solution and a ferric chloride aqueous solution. The iron content contained in the iron-containing aqueous liquid may be adsorbed on the colloidal particles to increase the particle size of the nucleating agent. When giving priority to such an effect, the value of (A / (A + B)) may be set to 0.99 or less, and may be set to 0.98 or less. The iron concentration is measured by ICP mass spectrometry.
 また、原水に鉄イオンが含まれている場合がある。このような場合、原水に含まれる鉄分の質量C、水酸化第二鉄コロイド粒子の水分散物に含まれる鉄分の質量をAとし、水酸化第二鉄コロイド粒子の水分散物以外の鉄分含有水性液に含まれる鉄分の質量をBとしたときに、A/(A+B+C)の値を0.9以上にすることが好ましく、0.95以上にすることがより好ましく、0.99以上にすることがさらに好ましい。(A/(A+B+C))の比率を1に近づけることによって、膜手段の閉塞を抑止でき、浄水コストを低減できる。なお、原水に含まれる鉄分や鉄分含有水性液に含有される鉄分は、コロイド粒子に吸着して造核剤の粒度を大きくする場合がある。このような効果を優先する場合には、(A/(A+B+C))の値を0.99以下にしてもよく、さらに0.98以下としてもよい。なお、鉄濃度はICP質量分析法にて測定する。 Also, the raw water may contain iron ions. In such a case, the mass C of iron contained in the raw water, the mass of iron contained in the aqueous dispersion of ferric hydroxide colloid particles is A, and iron content other than the aqueous dispersion of ferric hydroxide colloid particles is contained. When the mass of iron contained in the aqueous liquid is B, the value of A / (A + B + C) is preferably 0.9 or more, more preferably 0.95 or more, and 0.99 or more. More preferably. By making the ratio of (A / (A + B + C)) close to 1, blockage of the membrane means can be suppressed and water purification costs can be reduced. In some cases, the iron contained in the raw water or the iron contained in the iron-containing aqueous liquid is adsorbed on the colloidal particles to increase the particle size of the nucleating agent. When giving priority to such an effect, the value of (A / (A + B + C)) may be set to 0.99 or less, and may be set to 0.98 or less. The iron concentration is measured by ICP mass spectrometry.
 本発明の生活用浄水の製造方法では、造核剤を添加する前の原水のpHを4~8.5に調整することが好ましい。原水のpHを4~8.5に調整しておくことにより、原水中のヒ素の除去効率を高めることができる。この観点から、原水のpHは、4.5以上が好ましく、5以上がより好ましく、7.5以下が好ましく、7以下がより好ましく、6.5以下がさらに好ましい。pHの調整は、原水にアルカリまたは酸を加えればよい。前記アルカリとしては、水酸化ナトリウム、水酸化カリウム、アンモニアなどのアルカリ溶液を挙げることができる。安価で取扱いし易いという理由から、水酸化ナトリウムまたは水酸化カリウムが好ましく、水酸化ナトリウムがより好ましい。前記酸としては、塩酸、硝酸、酢酸、希硫酸などを挙げることができ、安価で取扱いしやすいという理由から、塩酸や希硫酸が好ましく、塩酸がより好ましい。 In the method for producing clean water for daily use of the present invention, it is preferable to adjust the pH of raw water before adding the nucleating agent to 4 to 8.5. By adjusting the pH of the raw water to 4 to 8.5, the removal efficiency of arsenic in the raw water can be increased. From this viewpoint, the pH of the raw water is preferably 4.5 or more, more preferably 5 or more, preferably 7.5 or less, more preferably 7 or less, and even more preferably 6.5 or less. The pH may be adjusted by adding an alkali or acid to the raw water. Examples of the alkali include alkali solutions such as sodium hydroxide, potassium hydroxide, and ammonia. Sodium hydroxide or potassium hydroxide is preferable and sodium hydroxide is more preferable because it is inexpensive and easy to handle. Examples of the acid include hydrochloric acid, nitric acid, acetic acid, dilute sulfuric acid, and the like, and hydrochloric acid and dilute sulfuric acid are preferable, and hydrochloric acid is more preferable because it is inexpensive and easy to handle.
 本発明で使用する膜手段は、原水中の微粒子や濁質などの異物を除去して、浄水を排出する。前記膜手段としては、例えば、逆浸透膜(RO膜)、ナノ濾過膜(NF膜)、精密濾過膜(MF膜)、限外濾過膜(UF膜)などの濾過膜を挙げることができる。比較的低圧で低コストで原水を濾過させることができるという観点から、膜手段としては、精密濾過膜(MF膜)、限外濾過膜(UF膜)が好ましい。 The membrane means used in the present invention removes foreign matters such as fine particles and turbidity in raw water and discharges purified water. Examples of the membrane means include filtration membranes such as reverse osmosis membranes (RO membranes), nanofiltration membranes (NF membranes), microfiltration membranes (MF membranes), and ultrafiltration membranes (UF membranes). As a membrane means, a microfiltration membrane (MF membrane) and an ultrafiltration membrane (UF membrane) are preferable from the viewpoint that raw water can be filtered at a relatively low pressure and low cost.
 一般に、原水中の重金属イオンなどを膜手段で除去することを目的とする場合、膜手段として、限外濾過膜(UF膜)や精密濾過膜(MF膜)は使用しない。重金属イオンの大きさに比べて、限外濾過膜(UF膜)、精密濾過膜(MF膜)の細孔径が大きく、原水中の重金属イオンが、膜手段を透過するからである。そのため、原水中の重金属イオンを膜手段で除去する場合には、細孔径の小さい逆浸透膜(RO膜)やナノ濾過膜(NF膜)を使用する必要がある。しかし、逆浸透膜(RO膜)は、濾過する際の通水圧力が高くなるために、原水供給手段を高性能化、あるいは、大型化する必要がある。また、動作時の電力コストも高くなる場合があり、捨て水が必要なために、水使用量のコストも高くなる。また、ナノ濾過膜(NF膜)を用いた場合、膜手段の細孔径が小さいために、原水処理量が低下する。一方、本発明では、造核剤が重金属イオンを捕捉して粒度の大きい凝集物を形成するので、重金属イオンを捕捉した凝集物を、細孔径が大きい限外濾過膜(UF膜)や精密濾過膜(MF膜)で除去することができる。細孔径が大きい限外濾過膜(UF膜)や精密濾過膜(MF膜)を用いていることにより、原水の処理量を高めることができる。 Generally, when the purpose is to remove heavy metal ions or the like in raw water with a membrane means, an ultrafiltration membrane (UF membrane) or a microfiltration membrane (MF membrane) is not used as the membrane means. This is because the ultrafiltration membrane (UF membrane) and microfiltration membrane (MF membrane) have larger pore diameters than the heavy metal ions, and the heavy metal ions in the raw water permeate the membrane means. Therefore, when removing heavy metal ions in raw water by a membrane means, it is necessary to use a reverse osmosis membrane (RO membrane) or nanofiltration membrane (NF membrane) having a small pore diameter. However, since reverse osmosis membranes (RO membranes) have high water flow pressures during filtration, it is necessary to increase the performance or size of the raw water supply means. In addition, the power cost during operation may be high, and the amount of water used is also high because waste water is required. Further, when a nanofiltration membrane (NF membrane) is used, the raw water treatment amount decreases because the pore diameter of the membrane means is small. On the other hand, in the present invention, since the nucleating agent captures heavy metal ions to form aggregates having a large particle size, the aggregates capturing heavy metal ions are converted into ultrafiltration membranes (UF membranes) or microfiltrations having large pore sizes. It can be removed with a film (MF film). By using an ultrafiltration membrane (UF membrane) or a microfiltration membrane (MF membrane) having a large pore diameter, the amount of raw water treated can be increased.
 また、本発明の生活用浄水の製造方法では、膜手段として、中空糸膜を使用することが好ましい。濾過方式としては、原水を全て濾過膜にて濾過して浄水にする全量濾過方式(デッドエンドろ過方式)と、原水を濾過膜の表面に対し平行に流して、浄水されなかった分の原水と濾過膜にて濾過された浄水の両方を排出するクロスフロー濾過方式があるが、浄水量を多くすることができる全量濾過方式を採用するのが好ましい。 Moreover, in the method for producing water for daily life of the present invention, it is preferable to use a hollow fiber membrane as the membrane means. As a filtration method, all raw water is filtered through a filtration membrane to make purified water (dead-end filtration method), and raw water is run parallel to the surface of the filtration membrane, Although there is a cross-flow filtration method that discharges both purified water that has been filtered through a filtration membrane, it is preferable to employ a full-volume filtration method that can increase the amount of purified water.
 本発明の浄水の製造方法では、造核剤の重量平均粒子径をA(nm)とし、膜モジュールが有する膜手段の細孔径をB(nm)としたときに、B/Aを1~20とすることがさらに好ましい。造核剤の重量平均粒子径A(nm)と、膜手段の細孔径B(nm)とが、前記関係を満足することにより、造核剤および凝集物が膜手段の細孔を閉塞することがなく、逆洗浄の回数を低減することができる。この観点から、B/Aは、2以上が好ましく、5以上がより好ましく、10以下が好ましく、7以下がより好ましい。膜手段の細孔径B(nm)は、バブルポイント法(JIS K 3832)に従って、求めることができる。 In the water purification method of the present invention, when the weight average particle diameter of the nucleating agent is A (nm) and the pore diameter of the membrane means of the membrane module is B (nm), B / A is 1 to 20 More preferably. When the weight average particle diameter A (nm) of the nucleating agent and the pore diameter B (nm) of the membrane means satisfy the above relationship, the nucleating agent and the aggregate block the pores of the membrane means. And the number of backwashes can be reduced. In this respect, B / A is preferably 2 or more, more preferably 5 or more, and preferably 10 or less, more preferably 7 or less. The pore diameter B (nm) of the membrane means can be determined according to the bubble point method (JIS K 3832).
 限外濾過膜(UF膜)の場合は、目の大きさは、分離対象物質を指標とする分画分子量により分類される。すなわち、対象膜で分離できるマーカーの分子量で分類を行う。代表的なマーカーを下記表に示した。なお、膜の阻止率は、供給液側の対象物質の濃度に対する透過液側の対象物質の濃度の比で定義され分離性能が評価できる。通常、阻止率が90%程度の対象物質の分子量を分画分子量としている。膜手段の細孔径B(nm)としては、下記表の分子量と分子径とから得られる近似曲線(Y=0.1506×M0.3371、Yは、分子径(nm)、Mは、分子量、R=0.9994)から算出される分子径Y(nm)を採用することとした。 In the case of an ultrafiltration membrane (UF membrane), the size of the eyes is classified according to the molecular weight cut off using the substance to be separated as an index. That is, classification is performed based on the molecular weight of the marker that can be separated on the target membrane. Representative markers are shown in the table below. The membrane rejection is defined by the ratio of the concentration of the target substance on the permeate side to the concentration of the target substance on the supply liquid side, and the separation performance can be evaluated. Usually, the molecular weight of the target substance having a rejection rate of about 90% is defined as the fractional molecular weight. The pore diameter B (nm) of the membrane means is an approximate curve (Y = 0.1506 × M 0.3371) where Y is the molecular diameter (nm), and M is the molecular weight. , R 2 = 0.9994), and the molecular diameter Y (nm) calculated from this was adopted.
Figure JPOXMLDOC01-appb-T000001
 (特許庁標準技術集:有機高分子多孔質体2-1-3-2.フラックス(分画分子量)参照)
Figure JPOXMLDOC01-appb-T000001
(Refer to JPO Standard Technology Collection: Organic Polymer Porous Material 2-1-3-2. Flux (fractional molecular weight))
 本発明の生活用浄水の製造方法において、膜手段の膜間差圧は、0.03MPa超であることが好ましく、0.04MPa以上であることがより好ましく、0.05MPa以上であることがさらに好ましく、0.45MPa以下であることが好ましく、0.3MPa以下であることがより好ましく、0.2MPa以下であることがさらに好ましく、0.15MPa以下であることが特に好ましい。膜手段の膜間差圧を前記範囲内にすることによって、原水の処理能力を高めることができ、所望量の生活用浄水を確保することができる。この場合、前記膜手段の一次側の圧力は、0.08MPa以上が好ましく、0.13MPa以上がより好ましく、0.15MPa以上がさらに好ましく、0.50MPa以下が好ましく、0.35MPa以下がより好ましく、0.25MPa以下がさらに好ましい。また、前記膜手段の二次側の圧力は、0.05MPa以上が好ましく、0.10MPa以上がより好ましく、0.12MPa以上がさらに好ましく、0.30MPa以下が好ましく、0.25MPa以下がより好ましく、0.20MPa以下がさらに好ましい。 In the method for producing domestic clean water of the present invention, the transmembrane pressure difference of the membrane means is preferably more than 0.03 MPa, more preferably 0.04 MPa or more, and further preferably 0.05 MPa or more. Preferably, it is 0.45 MPa or less, more preferably 0.3 MPa or less, further preferably 0.2 MPa or less, and particularly preferably 0.15 MPa or less. By setting the transmembrane differential pressure of the membrane means within the above range, the treatment capacity of raw water can be increased, and a desired amount of clean water for daily life can be ensured. In this case, the pressure on the primary side of the membrane means is preferably 0.08 MPa or more, more preferably 0.13 MPa or more, further preferably 0.15 MPa or more, preferably 0.50 MPa or less, more preferably 0.35 MPa or less. 0.25 MPa or less is more preferable. Further, the pressure on the secondary side of the membrane means is preferably 0.05 MPa or more, more preferably 0.10 MPa or more, further preferably 0.12 MPa or more, preferably 0.30 MPa or less, more preferably 0.25 MPa or less. 0.20 MPa or less is more preferable.
 本発明の生活用浄水の製造方法では、膜手段の濾過総面積S(m)に対する1時間当たりの濾過量V(m)の比(V/S、(m/hr))が、0.05以上であることが好ましく、0.1以上であることがより好ましく、0.3以上であることがさらに好ましく、0.5以上であることが特に好ましく、3.0以下であることが好ましく、2.5以下であることがより好ましく、2.0以下であることがさらに好ましい。前記比が、0.05以上3.0以下であると、単位濾過面積当たりの原水の処理量が所望の範囲となる。特に、平膜である多孔性膜を用いた孔拡散技術の場合には、単位濾過面積当たりの原水の処理量が極めて小さくなるし、原水の処理量を多くするために、濾過面積を増加すると濾過装置が大型化する。 In the method for producing domestic purified water of the present invention, the ratio (V / S, (m / hr)) of the filtration amount V (m 3 ) per hour to the total filtration area S (m 2 ) of the membrane means is 0 .05 or more, preferably 0.1 or more, more preferably 0.3 or more, particularly preferably 0.5 or more, and 3.0 or less. Preferably, it is 2.5 or less, more preferably 2.0 or less. When the ratio is 0.05 or more and 3.0 or less, the amount of raw water treated per unit filtration area becomes a desired range. In particular, in the case of a pore diffusion technique using a porous membrane that is a flat membrane, the amount of raw water treated per unit filtration area is extremely small, and in order to increase the amount of raw water treated, the filtration area is increased. The filtration device becomes larger.
 膜手段で濾過されて、得られた生活用浄水には、必要に応じて薬液を加えてもよい。前記薬液としては、特に限定されないが、例えば、次亜塩素酸、次亜塩素酸ナトリウム、次亜塩素酸水溶液などを挙げることができる。これらの中でも、次亜塩素酸ナトリウム水溶液を用いることが好ましい。次亜塩素酸ナトリウムを添加することにより、水中で次亜塩素酸イオンに電離するとともに、その一部が水と反応して、次亜塩素酸となる。これらの殺菌力によって浄水装置から吐出される生活用浄水において、例えば、浄水装置から各使用箇所までの配管における菌の繁殖を防止することができ、使用者が飲用するまでの浄水の安全性を維持することができる。 A chemical solution may be added to the purified water for domestic use obtained by filtering with a membrane means, if necessary. Although it does not specifically limit as said chemical | medical solution, For example, hypochlorous acid, sodium hypochlorite, hypochlorous acid aqueous solution, etc. can be mentioned. Among these, it is preferable to use a sodium hypochlorite aqueous solution. By adding sodium hypochlorite, it ionizes to hypochlorite ions in water, and part of it reacts with water to form hypochlorous acid. In the clean water for daily use discharged from the water purifier by these sterilizing power, for example, it is possible to prevent the growth of bacteria in the piping from the water purifier to each use location, and the safety of the purified water until the user drinks it. Can be maintained.
 次亜塩素酸ナトリウムを浄水に添加する場合、殺菌力と二次浄水装置での塩素除去効率などとの関係を考慮して、得られる浄水中の塩素濃度は、0.3mg/L以上が好ましく、0.4mg/L以上がより好ましく、0.5mg/L以上がさらに好ましく、0.8mg/L以下が好ましく、0.7mg/L以下がより好ましい。このように浄水中に塩素を含有させることにより、原水が塩素を含む水道水の場合に、本発明の浄水の製造方法により、塩素が除去された場合でも、浄水装置から流出する浄水に塩素を含有させることができ、また、塩素を含まない水を原水として用いた場合にも、塩素を添加することができ、衛生に優れたものとなる。 When sodium hypochlorite is added to purified water, the chlorine concentration in the obtained purified water is preferably 0.3 mg / L or more in consideration of the relationship between sterilizing power and chlorine removal efficiency in the secondary water purification device. 0.4 mg / L or more is more preferable, 0.5 mg / L or more is more preferable, 0.8 mg / L or less is preferable, and 0.7 mg / L or less is more preferable. By containing chlorine in the purified water in this way, even when the raw water is tap water containing chlorine, even if the chlorine is removed by the purified water manufacturing method of the present invention, chlorine is added to the purified water flowing out from the water purification device. Even when water that does not contain chlorine is used as raw water, chlorine can be added, resulting in excellent hygiene.
 本発明の製造方法により得られる生活用浄水としては、炊事・洗濯・入浴・シャワーなどに使用する生活用水、および、飲料水が挙げられる。特に、本発明の製造方法は、飲料水を製造するのに好適である。 The domestic purified water obtained by the production method of the present invention includes domestic water used for cooking, washing, bathing, showering, and drinking water. In particular, the production method of the present invention is suitable for producing drinking water.
 (2)浄水装置
 本発明の生活用浄水の製造装置は、本発明の生活用浄水の製造方法に使用される装置であって、
 原水供給路と、
 原水供給路に配置され、原水を送液する原水供給手段と、
 前記原水供給路を少なくとも2以上に分岐する複数の原水分岐路と、
 前記複数の原水分岐路に配置され、原水を濾過する複数の膜手段を備える膜モジュールと、
 前記複数の膜モジュールの一次側に接続する排出路と、
 前記複数の膜モジュールの二次側に接続する複数の浄水分岐路と、
 前記複数の浄水分岐路が合流する浄水路とを有しており、
 前記膜モジュールの一次側で、原水に造核剤を供給する手段を備え、造核剤の添加によって発生する凝集物を沈殿させて分離する分離槽を備えないことを特徴とする。
(2) Water purification apparatus The water purification apparatus for domestic use of the present invention is an apparatus used in the method for manufacturing water for domestic use of the present invention,
Raw water supply channel,
Raw water supply means that is disposed in the raw water supply path and feeds raw water,
A plurality of raw water branch paths that branch the raw water supply path into at least two or more;
A membrane module that is disposed in the plurality of raw water branches and includes a plurality of membrane means for filtering raw water;
A discharge path connected to a primary side of the plurality of membrane modules;
A plurality of water purification branches connected to the secondary side of the plurality of membrane modules;
A plurality of water purifying branches, and
The primary side of the membrane module is provided with means for supplying a nucleating agent to raw water, and is not provided with a separation tank for precipitating and separating aggregates generated by the addition of the nucleating agent.
 原水に造核剤を添加する態様では、原水中で、造核剤と不純物質とが接触して、造核剤が不純物質を捕捉する。不純物質を捕捉した造核剤は、膜手段を透過できず、不純物質とともに原水から取り除かれる。重量平均粒子径が5nm~160nmの水酸化第二鉄コロイド粒子の水分散物からなる造核剤を供給する手段は、特に限定されず、例えば、造核剤を貯蔵するタンクと、造核剤を供給する送液手段と、造核剤供給路とから構成される。なお、本発明の浄水装置は、小型化するという観点から、造核剤の添加によって発生する凝集物を沈殿させて分離する分離槽を設けない。 In the embodiment in which the nucleating agent is added to the raw water, the nucleating agent contacts the impurity in the raw water, and the nucleating agent captures the impurity. The nucleating agent that has captured the impurity cannot pass through the membrane means, and is removed from the raw water together with the impurity. Means for supplying a nucleating agent comprising an aqueous dispersion of ferric hydroxide colloid particles having a weight average particle diameter of 5 nm to 160 nm is not particularly limited. For example, a tank for storing a nucleating agent, a nucleating agent, and the like. It is comprised from the liquid feeding means which supplies nucleating agent, and a nucleating agent supply path. In addition, the water purifier of this invention does not provide the separation tank which precipitates and isolate | separates the aggregate which generate | occur | produces by addition of a nucleating agent from a viewpoint of reducing in size.
 本発明の生活用浄水の製造装置は、膜モジュールを逆洗浄できるように構成されていることが好ましい。膜モジュールの目詰まりを除去して、長期間、安定的に浄水を供給するためである。以下、本発明の製造装置を、逆洗浄が可能なように構成されたセントラル浄水装置の態様に基づいて説明する。 It is preferable that the production apparatus for domestic water purification of the present invention is configured so that the membrane module can be back-washed. This is for removing clogging of the membrane module and supplying clean water stably for a long period of time. Hereinafter, the manufacturing apparatus of this invention is demonstrated based on the aspect of the central water purifier comprised so that back washing | cleaning is possible.
 図5に示したセントラル浄水装置1は、原水供給路3と、原水供給路3に配置され、原水を送液する原水供給手段P1と、前記原水供給路3を少なくとも二以上に分岐する複数の原水分岐路5A,5Bと、前記複数の原水分岐路5A,5Bに配置され、原水を濾過する複数の膜モジュール9A,9Bと、前記膜モジュール9A,9Bが備える原水を濾過する膜手段9cの一次側に接続する排出路7A,7Bと、前記複数の膜モジュール9A,9Bの二次側に接続する複数の浄水分岐路11A,11Bと、前記複数の浄水分岐路11A,11Bが合流する浄水路13と、造核剤を貯蔵するタンク37と、造核剤を供給する供給手段P3とを備える。なお、本発明において、膜手段に対して、原水が供給される側を一次側とし、膜手段から浄水が排出される側を二次側と称する。 The central water purification apparatus 1 shown in FIG. 5 is disposed in the raw water supply path 3, the raw water supply path 3, a raw water supply means P <b> 1 that feeds the raw water, and a plurality of branches that branch the raw water supply path 3 into at least two or more A raw water branch 5A, 5B, a plurality of membrane modules 9A, 9B that are disposed in the plurality of raw water branches 5A, 5B and filter raw water, and membrane means 9c that filters the raw water included in the membrane modules 9A, 9B. Purified water where the discharge paths 7A and 7B connected to the primary side, the plurality of water purification branch paths 11A and 11B connected to the secondary side of the plurality of membrane modules 9A and 9B, and the plurality of water purification branch paths 11A and 11B merge. The passage 13 is provided with a tank 37 for storing a nucleating agent, and a supply means P3 for supplying the nucleating agent. In the present invention, the side on which raw water is supplied to the membrane means is referred to as the primary side, and the side from which the purified water is discharged from the membrane means is referred to as the secondary side.
 原水供給路3は、水道水、自然水などの浄化処理の対象となる原水を供給するものである。原水供給路3は、マンション、アパート、ビル、ホテル、複数の戸建て住宅などの建物に供給される水道本管から水道水を貯蔵する原水槽に接続するのがよいが、原水供給路3を水道本管に直接接続する事もできる。原水供給路3は、所定の管径を有する管路によって構成されている。原水供給路3は、原水供給路3を開閉するための流入弁(第1バルブV1)を備えることが好ましい。流入弁は、例えば、逆止弁としてもよい。 The raw water supply path 3 supplies raw water to be subjected to purification treatment such as tap water and natural water. The raw water supply channel 3 is preferably connected to a raw water tank that stores tap water from a water main supplied to a building such as an apartment, an apartment, a building, a hotel, or a plurality of detached houses. It can also be connected directly to the main. The raw water supply path 3 is constituted by a pipe line having a predetermined pipe diameter. The raw water supply path 3 preferably includes an inflow valve (first valve V1) for opening and closing the raw water supply path 3. For example, the inflow valve may be a check valve.
 原水供給路3には、原水を送液するための原水供給手段P1が配置されている。原水供給手段P1としては、例えば、縦型多段渦巻きポンプ、横型多段渦巻きポンプ、容積型のポンプなどを挙げることができる。これらの中でも、原水を安定的に加圧して送液するという理由から、原水供給手段P1としては、縦型多段渦巻きポンプを用いることが好ましい。 In the raw water supply path 3, raw water supply means P1 for sending raw water is disposed. Examples of the raw water supply means P1 include a vertical multi-stage centrifugal pump, a horizontal multi-stage centrifugal pump, and a positive displacement pump. Among these, it is preferable to use a vertical multistage centrifugal pump as the raw water supply means P1 because the raw water is stably pressurized and fed.
 原水供給路3の下流端は、分岐点4において、原水供給路3を複数に分岐する原水分岐路5A、5Bの上流端に接続している。原水分岐路5A、5Bは、所定の管径を有する管路によって構成される。原水分岐路5A,5Bはそれぞれ、原水分岐路5A,5Bを開閉するための流入弁(第2バルブV2と第3バルブV3)を備える。原水分岐路5A,5Bの下流端は、原水を濾過する膜モジュール9A,9Bに接続している。 The downstream end of the raw water supply path 3 is connected at the branch point 4 to the upstream ends of the raw water branch paths 5A and 5B that branch the raw water supply path 3 into a plurality. The raw water branch paths 5A and 5B are constituted by pipe lines having a predetermined pipe diameter. The raw water branch paths 5A and 5B include inflow valves (second valve V2 and third valve V3) for opening and closing the raw water branch paths 5A and 5B, respectively. The downstream ends of the raw water branch paths 5A and 5B are connected to membrane modules 9A and 9B that filter the raw water.
 膜モジュール9A、9Bは、原水中の微粒子や濁質などの異物を除去して、浄水を排出する。前記膜モジュール9A,9Bは、原水を濾過する膜手段9cと、前記膜手段9cを収納する円筒状の容器9dとを備える。前記膜モジュール9A,9Bは、前記円筒状の容器9dの内部において、原水を濾過する膜手段9cを挟んで、原水が供給される原水領域9eと、前記膜手段によって濾過された浄水が流入する浄水領域9fとを備えることが好ましい。 The membrane modules 9A and 9B remove foreign matters such as fine particles and turbidity in the raw water, and discharge purified water. The membrane modules 9A and 9B include membrane means 9c for filtering raw water and a cylindrical container 9d for housing the membrane means 9c. In the membrane modules 9A and 9B, the raw water region 9e to which raw water is supplied and the purified water filtered by the membrane means flow into the cylindrical container 9d with the membrane means 9c for filtering the raw water interposed therebetween. It is preferable to provide the purified water region 9f.
 前記膜モジュール9A,9Bは、原水流入口9gと、浄水排出口9hとを備え、さらに、濃縮水を排出するための濃縮水排出口9iとを備える。原水流入口9gと濃縮水排出口9iとは、膜モジュール9A,9Bの原水領域9eに接続し、浄水排出口9hは、膜モジュール9A,9Bの浄水領域9fに接続している。 The membrane modules 9A and 9B are provided with a raw water inlet 9g and a purified water outlet 9h, and further with a concentrated water outlet 9i for discharging concentrated water. The raw water inlet 9g and the concentrated water outlet 9i are connected to the raw water area 9e of the membrane modules 9A and 9B, and the purified water outlet 9h is connected to the purified water area 9f of the membrane modules 9A and 9B.
 前記膜モジュールは、外圧式または内圧式のいずれであってもよく、好ましくは内圧式である。また膜手段としては、限外濾過膜(UF膜)や精密濾過膜(MF膜)からなる中空糸膜を使用することが好ましい。 The membrane module may be either an external pressure type or an internal pressure type, preferably an internal pressure type. As membrane means, it is preferable to use a hollow fiber membrane comprising an ultrafiltration membrane (UF membrane) or a microfiltration membrane (MF membrane).
 本発明の浄水装置は、造核剤を供給する手段を有する。図5の態様では、造核剤を供給する手段は、造核剤を貯蔵するタンク37と、造核剤を供給する供給手段P3と、造核剤供給路6とで構成される。図5の実施形態では、原水槽35に貯蔵された原水に造核剤を供給するように構成されている。原水槽35に撹拌翼による撹拌、循環ポンプなどによる撹拌などの撹拌機能を設けることも好ましい。撹拌機能によって、造核剤と種々のイオンの接触効率を高めることができ、造核剤の大粒子径化に寄与することができる。なお、造核剤は、例えば、原水供給路5A,5Bにおいて、原水に直接供給するようにしてもよい。供給手段P3としては、例えば、縦型多段渦巻きポンプ、横型多段渦巻きポンプ、容積型のポンプなどを挙げることができる。造核剤供給路6は、所定の管径を有する管路から構成される。 The water purifier of the present invention has means for supplying a nucleating agent. In the embodiment of FIG. 5, the means for supplying the nucleating agent includes a tank 37 for storing the nucleating agent, a supplying means P3 for supplying the nucleating agent, and a nucleating agent supply path 6. In the embodiment of FIG. 5, the nucleating agent is supplied to the raw water stored in the raw water tank 35. It is also preferable to provide the raw water tank 35 with a stirring function such as stirring by a stirring blade or stirring by a circulation pump. The stirring function can increase the contact efficiency between the nucleating agent and various ions, and can contribute to increasing the particle size of the nucleating agent. In addition, you may make it supply a nucleating agent directly to raw | natural water, for example in raw | natural water supply path 5A, 5B. Examples of the supply unit P3 include a vertical multistage centrifugal pump, a horizontal multistage centrifugal pump, and a positive displacement pump. The nucleating agent supply path 6 is composed of a pipe having a predetermined pipe diameter.
 図5の態様の浄水の製造装置は、膜モジュール9A,9Bが備える膜手段9cの一次側に接続する排出路7A,7Bを有する。前記排出路は、主に膜モジュールを逆洗浄したときの逆洗浄水を排出するための流路である。前記排出路は、膜モジュール9A,9Bが備える膜手段9cの上流側に接続していればよく、例えば、膜モジュール9A,9Bの原水領域9eに接続する態様、原水分岐路5A,5Bに接続する態様、あるいは、膜モジュール9A,9Bの原水領域9e、および、原水分岐路5A,5Bの両方に接続する態様などを挙げることができる。 5 has the discharge paths 7A and 7B connected to the primary side of the membrane means 9c included in the membrane modules 9A and 9B. The discharge path is a flow path for discharging the backwash water when the membrane module is mainly backwashed. The said discharge path should just be connected to the upstream of the membrane means 9c with which membrane module 9A, 9B is equipped, for example, the aspect connected to the raw | natural water area | region 9e of membrane module 9A, 9B, it connects with raw | natural water branch 5A, 5B Or a mode of connecting to both the raw water region 9e of the membrane modules 9A and 9B and the raw water branch paths 5A and 5B.
 図5の態様では、膜モジュール9A,9Bの濃縮水排出口9iに、排出路7A、7Bの一方端が接続されている。排出路7A、7Bは、所定の管径を有する管路から構成され、それぞれの流路を開閉するための弁(第4バルブV4、および第5バルブV5)を備えることが好ましい。排出路7A,7Bは、さらに合流してもよい。 5, one ends of the discharge paths 7A and 7B are connected to the concentrated water discharge ports 9i of the membrane modules 9A and 9B. The discharge passages 7A and 7B are preferably composed of pipe passages having a predetermined pipe diameter, and are provided with valves (fourth valve V4 and fifth valve V5) for opening and closing the respective passages. The discharge paths 7A and 7B may further merge.
 前記膜モジュール9A、9Bの下流側には、浄水分岐路11A,11Bの上流端が接続されている。浄水分岐路11A,11Bは、膜モジュール9A,9Bの浄水排出口9hに接続している。浄水分岐路11A、11Bの下流側は、合流点17で接続し、複数の膜モジュールに接続する浄水分岐路11A,11Bが連通するように形成されている。浄水分岐路11A、11Bが連通することによって、一方の膜モジュールから排出された浄水を、他方の膜モジュールに逆流させることができる。合流点17には、流路を切り替えるための三方コック49が設けられている。なお、三方コック49の代わりに、浄水分岐路11A,11Bの下流側にそれぞれ、流路を切り替えるための開閉バルブを設けるようにしてもよい。 The upstream ends of the purified water branch paths 11A and 11B are connected to the downstream side of the membrane modules 9A and 9B. The purified water branch paths 11A and 11B are connected to the purified water discharge port 9h of the membrane modules 9A and 9B. The downstream sides of the purified water branch paths 11A and 11B are formed so that the purified water branch paths 11A and 11B connected at the junction 17 and connected to the plurality of membrane modules communicate with each other. By connecting the purified water branch paths 11 </ b> A and 11 </ b> B, the purified water discharged from one membrane module can be made to flow backward to the other membrane module. The junction 17 is provided with a three-way cock 49 for switching the flow path. Instead of the three-way cock 49, an open / close valve for switching the flow path may be provided on the downstream side of the purified water branch paths 11A and 11B.
 原水分岐路5A,5Bには、原水分岐路内を流れる原水の圧力を測定する圧力計14A,14Bが備えられていることが好ましい。また、浄水分岐路11A,11Bには、浄水分岐路内を流れる浄水の圧力を測定する圧力計16A,16Bが備えられていることが好ましい。 The raw water branch 5A and 5B are preferably provided with pressure gauges 14A and 14B for measuring the pressure of the raw water flowing in the raw water branch. Moreover, it is preferable that the pressure gauges 16A and 16B which measure the pressure of the purified water which flows through the inside of the purified water branch are provided in the purified water branches 11A and 11B.
 前記浄水分岐路11A,11Bの合流点17には、浄水路13が接続している。前記浄水路13には、浄水路13を開閉するための弁(第8バルブV8)が設けられている。前記浄水路13は、所定の管径を有する管路で構成されている。浄水路13には浄水を排出するための浄水排出路19が設けられていることが好ましい。浄水排出路19は、所定の管径を有する管路によって構成され、浄水排出路19を開閉するための弁(第9バルブV9)を備える。 The purified water path 13 is connected to the junction 17 of the purified water branch paths 11A and 11B. The water purification channel 13 is provided with a valve (eighth valve V8) for opening and closing the water purification channel 13. The water purification path 13 is composed of a pipe having a predetermined pipe diameter. It is preferable that the purified water path 13 is provided with a purified water discharge path 19 for discharging purified water. The purified water discharge path 19 is constituted by a pipeline having a predetermined pipe diameter, and includes a valve (a ninth valve V9) for opening and closing the purified water discharge path 19.
 図5に示した浄水の製造装置1は、制御手段21を備えることが好ましい。制御手段21は、例えば、インバーター制御部23、バルブ制御部25、膜差圧演算部27、表示器29、手動スイッチ31、タイマー33などを有していることが好ましい。 5 is preferably provided with a control means 21. The control means 21 preferably includes, for example, an inverter control unit 23, a valve control unit 25, a membrane differential pressure calculation unit 27, a display 29, a manual switch 31, a timer 33, and the like.
 図5の浄水装置1は、原水供給手段P1を制御するインバーター制御部23を有することが特に好ましい。原水供給手段P1をインバーターで制御して、原水供給手段が供給する原水の水圧を制御することが好ましい。インバーター制御部23は、例えば、浄水製造時には、原水の圧力がほぼ一定となるように原水供給手段P1を制御し、逆洗浄運転時には、原水の圧力が脈動するように原水供給手段P1を制御する。 It is particularly preferable that the water purifier 1 in FIG. 5 has an inverter control unit 23 that controls the raw water supply means P1. It is preferable to control the raw water pressure supplied by the raw water supply means by controlling the raw water supply means P1 with an inverter. For example, the inverter control unit 23 controls the raw water supply means P1 so that the pressure of the raw water is substantially constant during the production of purified water, and controls the raw water supply means P1 so that the pressure of the raw water pulsates during the reverse cleaning operation. .
 膜差圧演算部27は、圧力計14A,14B,16A,16Bの計測値を受信し、膜モジュール9A,9Bの一次側と二次側の膜間差圧を演算する。膜差圧演算部27は、例えば、前記膜間差圧のデータに応じて、バルブ制御部25に、浄水製造運転または逆洗浄運転を行うように、バルブの切り替えを指示する。 The membrane differential pressure calculation unit 27 receives the measurement values of the pressure gauges 14A, 14B, 16A, and 16B, and calculates the transmembrane pressure difference between the primary side and the secondary side of the membrane modules 9A and 9B. For example, the membrane differential pressure calculation unit 27 instructs the valve control unit 25 to switch the valve so as to perform the purified water production operation or the reverse cleaning operation in accordance with the data of the transmembrane differential pressure.
 バルブ制御部25は、手動スイッチ操作データ、膜差圧演算部が供給する膜間差圧データ、タイマーが供給する時間データなどに基づいて、バルブの開閉を行う。バルブ制御部と各バルブは、有線または無線で接続されていることが好ましい。 The valve control unit 25 opens and closes the valve based on manual switch operation data, transmembrane pressure data supplied by the membrane pressure calculation unit, time data supplied by a timer, and the like. The valve controller and each valve are preferably connected by wire or wirelessly.
 タイマー33は、例えば、通常濾過運転の時間および逆洗浄運転の時間を計測し、それぞれの運転時間が所定時間に達した場合には、バルブ制御部25に、浄水製造運転または逆洗浄運転を行うように、バルブの切り替えを指示することができる。 For example, the timer 33 measures the time of the normal filtration operation and the time of the back washing operation, and when each operation time reaches a predetermined time, the water purification manufacturing operation or the back washing operation is performed on the valve control unit 25. Thus, it is possible to instruct switching of the valve.
 表示器29は、例えば、圧力計から受信した圧力値、および、膜間差圧、現在の運転工程などを表示することができる。 The indicator 29 can display, for example, the pressure value received from the pressure gauge, the transmembrane pressure difference, the current operation process, and the like.
 図5の浄水の製造装置1は、浄水に、次亜塩素酸、次亜塩素酸ナトリウムなどの薬液を添加するための薬液タンク41および、薬液を送液するためのポンプP2を有する。なお、図5では、浄水の製造装置1によって得られた浄水が、受水槽45に供給されるように図示されているが、受水槽45は、必ずしも必要ではない。 5 has a chemical tank 41 for adding a chemical solution such as hypochlorous acid or sodium hypochlorite to the purified water, and a pump P2 for feeding the chemical solution. In addition, in FIG. 5, although the purified water obtained by the purified water manufacturing apparatus 1 is shown in figure so that it may be supplied to the water receiving tank 45, the water receiving tank 45 is not necessarily required.
 原水槽35および受水槽45が、レベル計L1,L2を備えることも好ましい。例えば、レベル計L1が計測する原水槽35の水位データに基づいて、原水が一定量処理されたときに、バルブ制御部25が、通常濾過運転と逆洗浄運転を切り替えるように、バルブの切り替えを指示するようにしてよい。 It is also preferable that the raw water tank 35 and the water receiving tank 45 include level meters L1 and L2. For example, based on the water level data of the raw water tank 35 measured by the level meter L1, the valve control unit 25 switches the valve so that the normal filtration operation and the reverse cleaning operation are switched when a certain amount of raw water is processed. You may be instructed.
 図5の実施形態では、膜モジュールとして、第一膜モジュール9Aと第二膜モジュール9Bとを有する形態に基づいて説明するが、膜モジュールは、2以上であることが好ましい。例えば、第一膜モジュールと第二膜モジュールとからなる1対の膜モジュールセットを複数有する態様を挙げることができる。本発明の浄水装置が、第一膜モジュールと第二膜モジュールとからなる1対の膜モジュールセットを複数有することにより、原水の処理量を大きくすることができる。 In the embodiment of FIG. 5, the membrane module is described based on a form having the first membrane module 9A and the second membrane module 9B, but the number of membrane modules is preferably two or more. For example, the aspect which has two or more pairs of membrane module sets which consist of a 1st membrane module and a 2nd membrane module can be mentioned. Since the water purifier of the present invention has a plurality of pairs of membrane module sets each composed of a first membrane module and a second membrane module, the amount of raw water treated can be increased.
 図5の実施形態では、濾過状態にある1つの膜モジュールから得られた浄水を、逆洗浄対象となる別の1つの膜モジュールの逆洗水として使用するように構成されている。すなわち、濾過状態の膜モジュールと逆洗対象の膜モジュールとの数の比が、1:1となっている。しかし、濾過状態にある複数の膜モジュールから得られた浄水を合流させて、逆洗対象となる1つの膜モジュールの逆洗水として使用するように構成してもよいし、濾過状態にある1つの膜モジュールから得られた浄水を分岐させて、逆洗対象となる複数の膜モジュールの逆洗水として使用するように構成してもよい。しかしながら、濾過状態の膜モジュール:逆洗対象の膜モジュール=多:1の場合には、逆洗水の圧力が高くなりすぎて、逆洗対象の膜モジュールが備える濾過膜を損傷するおそれがある。一方、濾過状態の膜モジュール:逆洗対象の膜モジュール=1:多の場合には、逆洗水の圧力が低下するので、逆洗浄効率が低下するおそれがある。従って、濾過状態の膜モジュールと逆洗対象の膜モジュールとの数の比は、1:1とすることが好ましい。 In the embodiment of FIG. 5, the purified water obtained from one membrane module in a filtered state is configured to be used as backwash water for another one membrane module to be backwashed. That is, the ratio of the number of membrane modules in a filtered state to the membrane module to be backwashed is 1: 1. However, the purified water obtained from a plurality of membrane modules in a filtered state may be merged and used as backwash water for one membrane module to be backwashed, or 1 in a filtered state. You may comprise so that the purified water obtained from one membrane module may be branched and used as the backwash water of the several membrane module used as the backwash object. However, in the case of membrane module in filtration state: membrane module to be backwashed = multiple: 1, the pressure of backwashing water becomes too high, and there is a risk of damaging the filtration membrane provided in the membrane module to be backwashed. . On the other hand, when the membrane module in the filtered state: the membrane module to be backwashed = 1: many, the pressure of backwashing water is lowered, so that the backwashing efficiency may be lowered. Therefore, it is preferable that the ratio of the number of membrane modules in a filtered state and the number of membrane modules to be backwashed is 1: 1.
 本発明の浄水の製造装置は、マンション、アパート、ビル、ホテル、複数の戸建てなどの建物に浄水を供給しうるセントラル浄水装置として好適に使用できる。前記セントラル浄水装置の浄水の供給量は、供給先の数や水使用量に応じて適宜設定する。例えば100戸から200戸のマンション1棟に1個のセントラル浄水装置を設置する場合を想定すると、前記セントラル浄水装置の浄水の供給量は、3,000L/時以上が好ましく、4,000L/時以上がより好ましく、5,000L/時以上がさらに好ましく、8,000L/時以下が好ましく、7,000L/時以下がより好ましく、6,000L/時以下がさらに好ましい。 The water purification apparatus of the present invention can be suitably used as a central water purification apparatus that can supply purified water to buildings such as apartments, apartments, buildings, hotels, and multiple houses. The amount of purified water supplied from the central water purification apparatus is appropriately set according to the number of supply destinations and the amount of water used. For example, assuming that one central water purification device is installed in one apartment building of 100 to 200 units, the supply amount of purified water of the central water purification device is preferably 3,000 L / hour or more, and 4,000 L / hour. More preferably, 5,000 L / hour or more is more preferred, 8,000 L / hour or less is preferred, 7,000 L / hour or less is more preferred, and 6,000 L / hour or less is more preferred.
 次に、図5の製造装置を用いた生活用浄水の製造方法の具体例について説明する。図5の浄水装置を用いた浄水の製造方法は、少なくとも第一膜モジュールと第二膜モジュールとを有する複数の膜モジュールに原水を並列に供給して、原水を複数の膜モジュールで濾過することにより浄水を製造する浄水製造工程と、第一膜モジュールまたは第二膜モジュールの一方に、原水を供給して濾過し、得られた浄水の少なくとも一部を、逆洗水として、他方の膜モジュールの下流側から上流側に逆流させて、他方の膜モジュールを逆洗浄する逆洗工程とを有することを特徴とする。 Next, a specific example of a method for producing domestic clean water using the production apparatus of FIG. 5 will be described. The water purification method using the water purification apparatus of FIG. 5 supplies raw water in parallel to a plurality of membrane modules having at least a first membrane module and a second membrane module, and filters the raw water through the plurality of membrane modules. The purified water production process for producing purified water and supplying the raw water to one of the first membrane module or the second membrane module and filtering, and at least a part of the obtained purified water as backwash water, the other membrane module And a backwashing step of backwashing the other membrane module by backflowing from the downstream side to the upstream side.
 図6は、浄水製造工程における本発明の浄水装置1の通水状態を示す図である。図6に示すように、浄水製造工程では、第1~第3バルブV1~V3、第8バルブV8を解放し、第4~第7バルブV4~V7、および、第9バルブV9を閉鎖する。これにより、原水供給路3、原水分岐路5A,5Bと、浄水分岐路11A,11Bと、浄水路13とが、膜モジュール9A,9Bを介して連通した原水処理ラインが形成される。バルブの開閉操作は、バルブ制御部による自動制御でもよいし、手動で制御してもよい。 FIG. 6 is a view showing a water flow state of the water purifier 1 of the present invention in the water purification production process. As shown in FIG. 6, in the water purification manufacturing process, the first to third valves V1 to V3 and the eighth valve V8 are released, and the fourth to seventh valves V4 to V7 and the ninth valve V9 are closed. Thus, a raw water treatment line is formed in which the raw water supply path 3, the raw water branch paths 5A and 5B, the purified water branch paths 11A and 11B, and the purified water path 13 communicate with each other through the membrane modules 9A and 9B. The valve opening / closing operation may be automatic control by the valve control unit or may be manually controlled.
 原水供給手段P1は、原水を加圧して原水供給路に送液することが好ましい。原水の圧力は、使用する膜モジュールの許容圧力に応じて、適宜設定されることが好ましい。例えば、限外濾過膜(UF膜)及び精密濾過膜(MF膜)の場合、許容圧力は、約0.35MPa程度であり、加圧された原水の圧力Pfは、0.08MPa以上が好ましく、0.13MPa以上がより好ましく、0.15MPa以上がさらに好ましく、0.35MPa以下が好ましく、0.32MPa以下がより好ましく、0.30MPa以下がさらに好ましい。加圧された原水の圧力Pfが、許容圧力を超えると、濾過膜が損傷しやすくなる。また、加圧された原水の圧力Pfが低すぎると、原水の流量が少なくなってしまうからである。なお、浄水製造工程においては、原水の圧力Pfは、ほぼ一定であることが好ましい。 The raw water supply means P1 preferably pressurizes the raw water and sends it to the raw water supply path. The pressure of the raw water is preferably set as appropriate according to the allowable pressure of the membrane module to be used. For example, in the case of an ultrafiltration membrane (UF membrane) and a microfiltration membrane (MF membrane), the allowable pressure is about 0.35 MPa, and the pressure Pf of the pressurized raw water is preferably 0.08 MPa or more, 0.13 MPa or more is more preferable, 0.15 MPa or more is more preferable, 0.35 MPa or less is preferable, 0.32 MPa or less is more preferable, and 0.30 MPa or less is more preferable. When the pressure Pf of the pressurized raw water exceeds the allowable pressure, the filtration membrane is easily damaged. Moreover, if the pressure Pf of the pressurized raw water is too low, the flow rate of the raw water is reduced. In the purified water production process, the pressure Pf of the raw water is preferably substantially constant.
 原水は、分岐点4で分岐して、原水分岐路5A,5Bを通って、第一および第二膜モジュール9A,9Bに供給される。原水は、第一および第二膜モジュール9A,9Bで濾過される。原水に含まれる異物や濁質などが、膜モジュールで除去される。また、原水が含有する不純物質(重金属イオン、ヒ素、フッ素など)が、造核剤に捕捉され、膜手段により原水から除去される。原水を第一および第二膜モジュール9A,9Bで濾過する際には、第4および第5バルブV4,V5を解放して、濃縮水を、排出路7A,7Bから排出しながら濾過するクロスフロー方式を採用してもよい。また、第4及び第5バルブV4,V5を閉鎖して、原水を濾過するデッドエンド方式を採用してもよい。デッドエンド方式を採用する場合には、膜モジュール9A,9B内の溜まり部に異物が蓄積していくことになるので、時折、第4及び第5バルブV4,V5を解放して、異物を排出することが好ましい。 The raw water branches at the branch point 4 and is supplied to the first and second membrane modules 9A and 9B through the raw water branch paths 5A and 5B. The raw water is filtered by the first and second membrane modules 9A and 9B. Foreign matter and turbidity contained in the raw water are removed by the membrane module. Impurities contained in the raw water (heavy metal ions, arsenic, fluorine, etc.) are captured by the nucleating agent and removed from the raw water by the membrane means. When the raw water is filtered by the first and second membrane modules 9A and 9B, the fourth and fifth valves V4 and V5 are opened, and the concentrated water is filtered while being discharged from the discharge passages 7A and 7B. A method may be adopted. Moreover, you may employ | adopt the dead end system which closes the 4th and 5th valve | bulb V4, V5, and filters raw | natural water. When the dead end method is adopted, foreign matter accumulates in the reservoirs in the membrane modules 9A and 9B, so the fourth and fifth valves V4 and V5 are occasionally released to discharge the foreign matter. It is preferable to do.
 第一および第二膜モジュール9A,9Bから排出された浄水はそれぞれ、浄水分岐路11A,11Bを通って合流点17で合流し、浄水路13に流出する。 The purified water discharged from the first and second membrane modules 9A and 9B merges at the junction 17 through the purified water branch paths 11A and 11B, and flows out to the purified water path 13, respectively.
 次に、逆洗工程について、説明する。逆洗工程では、第一膜モジュールまたは第二膜モジュールの一方に、原水を供給して濾過し、得られた浄水の少なくとも一部を、逆洗水として、他方の膜モジュールの下流側から上流側に逆流させて、他方の膜モジュールを逆洗浄する。 Next, the backwash process will be described. In the backwashing process, raw water is supplied to one of the first membrane module or the second membrane module and filtered, and at least a part of the obtained purified water is used as backwash water from the downstream side of the other membrane module. The other membrane module is back-washed by flowing back to the side.
 以下、図7を参照しながら、第一膜モジュールを濾過状態として運転し、第二膜モジュールを逆洗する場合について、具体的に説明する。第一膜モジュールを濾過状態とし、第二膜モジュールを逆洗状態とするには、第1、第2バルブV1、V2、第5バルブV5、第8バルブV8を解放し、第3、第4、第6、第7バルブV3、V4、V6、V7、第9バルブV9を閉鎖する。バルブの開閉操作は、バルブ制御部による自動制御でもよいし、手動で制御してもよい。このバルブ操作により、原水供給路3と、原水分岐路5Aと、浄水分岐路11Aと、浄水路13とが、膜モジュール9Aを介して連通した原水処理ラインが形成される。また、浄水分岐路11Bと、排出路7Bとが、第二膜モジュール9Bを介して連通した逆洗ラインが形成される。 Hereinafter, the case where the first membrane module is operated in the filtration state and the second membrane module is backwashed will be described in detail with reference to FIG. In order to place the first membrane module in the filtration state and the second membrane module in the backwash state, the first and second valves V1, V2, the fifth valve V5, and the eighth valve V8 are released, and the third, fourth, The sixth and seventh valves V3, V4, V6, V7 and the ninth valve V9 are closed. The valve opening / closing operation may be automatic control by the valve control unit or may be manually controlled. By this valve operation, a raw water treatment line is formed in which the raw water supply path 3, the raw water branch path 5A, the purified water branch path 11A, and the purified water path 13 communicate with each other through the membrane module 9A. Further, a backwash line is formed in which the purified water branch path 11B and the discharge path 7B communicate with each other via the second membrane module 9B.
 第一膜モジュール9Aから排出された浄水の少なくとも一部は、逆洗水として、浄水分岐路11Bを逆流して、第二膜モジュール9Bの下流側の浄水排出口9hから第二膜モジュール9Bに侵入する。第二膜モジュール9B内に侵入した逆洗水は、第二膜モジュール9B内に配置された膜手段9cを透過して、上流側の濃縮水排出口9iから、排出路7Bへと流出する。この際、第二膜モジュール9Bの膜手段9cに付着している異物が遊離し、逆洗水とともに、排出路7Bへと流出する。逆洗水と第二膜モジュール9Bに付着していた異物は、濃縮水排出口9iに接続する排出路7Bから浄水装置外に排出される。膜手段9cに付着している異物には、膜手段9cに付着した造核剤、および、造核剤によって形成された凝集物が含まれる。 At least a part of the purified water discharged from the first membrane module 9A flows back through the purified water branch 11B as backwash water, and passes from the purified water discharge port 9h downstream of the second membrane module 9B to the second membrane module 9B. invade. The backwash water that has entered the second membrane module 9B passes through the membrane means 9c disposed in the second membrane module 9B, and flows out from the upstream concentrated water discharge port 9i to the discharge path 7B. At this time, the foreign matter adhering to the membrane means 9c of the second membrane module 9B is released and flows out into the discharge path 7B together with the backwash water. The foreign matter adhering to the backwash water and the second membrane module 9B is discharged out of the water purifier from the discharge path 7B connected to the concentrated water discharge port 9i. The foreign matter adhering to the film means 9c includes a nucleating agent adhering to the film means 9c and an aggregate formed by the nucleating agent.
 また、第一膜モジュール9Aから排出された浄水の残部は、浄水路13に流出する。これにより、第二膜モジュール9Bを逆洗浄しながらも、一定量の浄水を排出し続けることができる。なお、第8バルブV8を閉じて、第一膜モジュール9Aから排出された浄水の全部を逆洗水としてもよい。 Further, the remaining portion of the purified water discharged from the first membrane module 9A flows out to the purified water channel 13. Thereby, it is possible to continue discharging a certain amount of purified water while backwashing the second membrane module 9B. Note that the eighth valve V8 may be closed and all the purified water discharged from the first membrane module 9A may be backwashed water.
 前記では、逆洗ラインとして、浄水分岐路11Bと、第二膜モジュール9B、排出路7Bが連通したラインを採用したが、例えば、浄水分岐路11Bと、原水分岐路5Bと、排出路15Bとが、第二膜モジュール9Bを介して連通したラインを採用してもよい。 In the above, a line in which the purified water branch path 11B, the second membrane module 9B, and the discharge path 7B communicate with each other is adopted as the backwash line. For example, the purified water branch path 11B, the raw water branch path 5B, and the discharge path 15B However, you may employ | adopt the line connected via the 2nd membrane module 9B.
 逆洗浄工程では、原水供給手段P1は、原水の水圧を脈動させながら、第一膜モジュール9Aに原水を供給してもよい。原水の水圧を脈動させながら、第一膜モジュール9Aに原水を供給することにより、第一膜モジュール9Aから排出される浄水、すなわち逆洗水の水圧が脈動するので、第二膜モジュール9Bの逆洗浄効率が高くなるからである。原水の水圧を脈動させる方法としては、例えば、原料供給手段P1の回転数をインバーター制御部23により連続的に変化させることが好ましい。 In the reverse cleaning step, the raw water supply means P1 may supply the raw water to the first membrane module 9A while pulsating the water pressure of the raw water. Supplying the raw water to the first membrane module 9A while pulsating the water pressure of the raw water pulsates the purified water discharged from the first membrane module 9A, that is, the backwash water pressure, so that the reverse of the second membrane module 9B This is because the cleaning efficiency is increased. As a method of pulsating the water pressure of the raw water, for example, it is preferable to continuously change the rotation speed of the raw material supply means P1 by the inverter control unit 23.
 次に、図8を参照しながら、第二膜モジュール9Bを濾過状態として運転し、第一膜モジュール9Aを逆洗する場合について説明する。第二膜モジュール9Bを濾過状態として運転し、第一膜モジュール9Aを逆洗状態とするには、第1、第3バルブV1、V3、第4バルブV4、第8バルブV8を解放し、第2、第5、第6、第7バルブV2,V5,V6、V7、および、第9バルブV9を閉鎖して、同様の操作を行えばよい。バルブの開閉操作は、バルブ制御部による自動制御でもよいし、手動で制御してもよい。このバルブ操作により、原水供給路3と、原水分岐路5Bと、浄水分岐路11Bと、浄水路13とが、第二膜モジュール9Bを介して連通した原水処理ラインが形成する。また、浄水分岐路11Aと、排出路7Aとが、第一膜モジュール9Aを介して連通した逆洗ラインを形成する。 Next, the case where the second membrane module 9B is operated in the filtration state and the first membrane module 9A is backwashed will be described with reference to FIG. In order to operate the second membrane module 9B in the filtration state and put the first membrane module 9A in the backwash state, the first, third valves V1, V3, the fourth valve V4, and the eighth valve V8 are released, The second, fifth, sixth, and seventh valves V2, V5, V6, V7, and the ninth valve V9 may be closed to perform the same operation. The valve opening / closing operation may be automatic control by the valve control unit or may be manually controlled. By this valve operation, a raw water treatment line is formed in which the raw water supply path 3, the raw water branch path 5B, the purified water branch path 11B, and the purified water path 13 communicate with each other through the second membrane module 9B. Moreover, the purified water branch path 11A and the discharge path 7A form a backwash line communicating with the first membrane module 9A.
 前記では、逆洗ラインとして、浄水分岐路11Aと、排出路7Aとが、第一膜モジュール9Aを介して連通した逆洗ラインを採用したが、例えば、逆洗ラインとして、浄水分岐路11Aと、原水分岐路5Aと、排出路15Aとが、第一膜モジュール9Aを介して連通したラインを採用してもよい。 In the above description, the backwash line in which the purified water branch path 11A and the discharge path 7A communicated with each other via the first membrane module 9A is adopted as the backwash line. For example, as the backwash line, the purified water branch path 11A and A line in which the raw water branch 5A and the discharge path 15A communicate with each other via the first membrane module 9A may be adopted.
 また、原水に造核剤を添加して、膜手段を備える膜モジュールで濾過する本発明の浄水の製造方法は、例えば、以下の工程を含み、下記(2)~(4)の工程を適宜切り替えながら行うことが好ましい。
(1)原水に造核剤を添加する工程
(2)第一膜モジュールと第二膜モジュールの両方で原水を濾過する浄水製造工程
(3)第一膜モジュールを濾過状態とし、第二膜モジュールを逆洗状態とする逆洗浄工程
(4)第二膜モジュールを濾過状態とし、第一膜モジュールを逆洗状態とする逆洗浄工程
 運転の切り替えは、例えば、手動スイッチ操作データ、膜差圧演算部が供給する差圧データ、タイマーが供給する時間データ等に基づいて行うことが好ましい。
The method for producing purified water of the present invention in which a nucleating agent is added to raw water and filtered through a membrane module provided with membrane means includes, for example, the following steps, and includes the following steps (2) to (4) as appropriate: It is preferable to carry out switching.
(1) Step of adding a nucleating agent to raw water (2) Purified water production step of filtering raw water through both the first membrane module and the second membrane module (3) The first membrane module is put into a filtered state, and the second membrane module (4) Backwashing process in which the second membrane module is in the filtered state and the first membrane module is in the backwashed state. For example, manual switch operation data, membrane differential pressure calculation This is preferably performed based on differential pressure data supplied by the unit, time data supplied by the timer, and the like.
浄水製造工程の運転時間は、原水の水質や、処理速度などに応じて適宜設定すればよい。従って、浄水製造工程の時間は、数分、数時間~数日という範囲で変化する場合がある。逆洗浄工程の時間は、例えば、30秒以上が好ましく、1分以上がより好ましく、5分以上が特に好ましく、20分以下が好ましく、10分以下がより好ましく、7分以下が特に好ましい。 What is necessary is just to set the operation time of a purified water manufacturing process suitably according to the quality of raw | natural water, a processing speed, etc. Therefore, the time of the water purification production process may vary from several minutes to several hours to several days. The time for the back washing step is, for example, preferably 30 seconds or more, more preferably 1 minute or more, particularly preferably 5 minutes or more, preferably 20 minutes or less, more preferably 10 minutes or less, and particularly preferably 7 minutes or less.
 以上、本発明を好ましい実施形態に基づいて説明したが、本発明は、前記実施形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で、各実施形態の形状、構成、配置、材料、工程などを適宜変更することができる。また、各実施形態にて示した構成、配置、材料、形状、数値範囲、工程などの規定は、各々独立に、或いは、何れか2以上の規定を組み合わせて適用可能である。 As described above, the present invention has been described based on preferred embodiments, but the present invention is not limited to the above-described embodiments, and the shape, configuration, arrangement, and the like of each embodiment are within the scope of the present invention. Materials, processes, and the like can be changed as appropriate. In addition, the definitions of the configuration, arrangement, material, shape, numerical range, process, and the like shown in each embodiment can be applied independently or in combination of any two or more rules.
 以下、本発明を実施例によって詳細に説明するが、本発明は、下記実施例によって限定されるものではなく、本発明の趣旨を逸脱しない範囲の変更、実施の態様は、いずれも本発明の範囲内に含まれる。 Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples, and all modifications and embodiments without departing from the gist of the present invention are not limited thereto. Included in range.
[造核剤(水酸化第二鉄のコロイド粒子の水分散物)の合成]
 原料として塩化第二鉄、水酸化ナトリウム、水を用意し、混合後のpHが2.5前後、濃度が鉄濃度換算で5,000mg/Lとなるように調整し、ほぼ水と同程度の粘度の水分散物を得た。
[造核剤の粒子径制御]
 造核剤の重量平均粒子径は、塩化第二鉄の比率と比例し、塩化第二鉄と水酸化ナトリウムの混合比によって、制御した。
[凝集剤]
 比較用の凝集剤としては、以下の市販品を使用した。
凝集剤1:ポリグルタミン酸系凝集剤
凝集剤2:ポリグルタミン酸系凝集剤(磁性体含有)
凝集剤3:無機系凝集剤(シラスが主成分)
凝集剤4:カルシウム塩系凝集剤
凝集剤5:ゼオライト系凝集剤
[Synthesis of nucleating agent (aqueous dispersion of ferric hydroxide colloidal particles)]
Prepare ferric chloride, sodium hydroxide, and water as raw materials, adjust the pH after mixing to around 2.5, and adjust the concentration to 5,000 mg / L in terms of iron concentration. An aqueous dispersion of viscosity was obtained.
[Particle size control of nucleating agent]
The weight average particle diameter of the nucleating agent was proportional to the ratio of ferric chloride and was controlled by the mixing ratio of ferric chloride and sodium hydroxide.
[Flocculant]
As comparative flocculants, the following commercial products were used.
Flocculant 1: Polyglutamic acid-based flocculant Flocculant 2: Polyglutamic acid-based flocculant (including magnetic substance)
Flocculant 3: Inorganic flocculant (mainly Shirasu)
Coagulant 4: Calcium salt type coagulant Coagulant 5: Zeolite type coagulant
 [金属の除去試験]
 (1)各種金属に対する除去試験
 各種金属成分を所定濃度に調整した原水50mLのそれぞれに、造核剤(重量平均粒子径約10nmの水酸化第二鉄のコロイド粒子の水分散物)を添加した。造核剤の添加量は、原水に対する全鉄濃度が0.6mg/Lとなるように添加した。造核剤を添加後、被処理液を1分間撹拌して、凝集物を発生させた。その後、被処理液を濾過膜(ろ紙:AdvantecNo.2、孔径:5μm)で濾過し、除去率を算出した。算出した除去率を表2に示した。なお、ろ紙による濾過実験では、原水に含まれる金属成分がろ紙に吸着されることがある。そのため、ろ紙も含めた全体の除去率と、造核剤を添加せずにブランク試験を行い、ろ紙の影響を排除した除去率(薬品のみ)を示した。この結果より、本発明で使用する造核剤が、各種金属を除去しうることが分かる。
[Metal removal test]
(1) Removal test for various metals A nucleating agent (an aqueous dispersion of ferric hydroxide colloid particles having a weight average particle diameter of about 10 nm) was added to 50 mL of raw water in which various metal components were adjusted to predetermined concentrations. . The nucleating agent was added so that the total iron concentration relative to the raw water was 0.6 mg / L. After the nucleating agent was added, the liquid to be treated was stirred for 1 minute to generate aggregates. Thereafter, the liquid to be treated was filtered through a filter membrane (filter paper: Advantec No. 2, pore size: 5 μm), and the removal rate was calculated. The calculated removal rate is shown in Table 2. In the filtration experiment using filter paper, metal components contained in the raw water may be adsorbed on the filter paper. Therefore, the entire removal rate including the filter paper and a blank test without adding the nucleating agent were performed, and the removal rate (only chemicals) excluding the influence of the filter paper was shown. This result shows that the nucleating agent used in the present invention can remove various metals.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
 (2)造核剤と凝集剤の比較試験
 金属濃度を0.02mg/Lに調整した原水50mLに、造核剤(重量平均粒子径約10nmの水酸化第二鉄コロイド粒子の水分散物)および凝集剤1~5をそれぞれ添加した。凝集剤の添加量は、濃度が0.6mg/Lとなるようにし、造核剤の添加量は、全鉄濃度で0.6mg/Lとなるようにした。造核剤および凝集剤を添加後、混合液を1分間撹拌して、凝集物を発生させた。その後、被処理液を濾過膜(AdvantecNo.2:孔径:5μm)で濾過し、除去率および除去負荷量指数を算出した。なお、除去負荷量指数は、濾過処理前後の濃度差×処理量で表される総合的な濾過性能の判断指標である。重金属としては、AsおよびCdを用いた。濾過処理前後の重金属濃度および除去負荷量指数を図9~図13に示した。また、重金属の除去率を表3に示した。なお、ろ紙による濾過実験では、原水に含まれる重金属がろ紙に吸着されることがある。そのため、ろ紙も含めた全体の除去率と、造核剤および凝集剤を添加せずにブランク試験を行い、ろ紙の影響を排除した除去率(薬品のみ)を示した。
(2) Comparative test of nucleating agent and flocculant To 50 mL of raw water adjusted to a metal concentration of 0.02 mg / L, a nucleating agent (an aqueous dispersion of ferric hydroxide colloid particles having a weight average particle diameter of about 10 nm). And flocculants 1-5 were added respectively. The addition amount of the flocculant was set to 0.6 mg / L, and the addition amount of the nucleating agent was set to 0.6 mg / L at the total iron concentration. After adding the nucleating agent and the flocculant, the mixed solution was stirred for 1 minute to generate agglomerates. Thereafter, the liquid to be treated was filtered through a filtration membrane (Advantec No. 2: pore size: 5 μm), and the removal rate and removal load index were calculated. The removal load index is a comprehensive index for determining filtration performance expressed by the concentration difference before and after the filtration process × the treatment amount. As and Cd were used as heavy metals. The heavy metal concentration and the removal load index before and after the filtration treatment are shown in FIGS. The removal rate of heavy metals is shown in Table 3. In a filtration experiment using filter paper, heavy metals contained in raw water may be adsorbed on the filter paper. Therefore, the overall removal rate including the filter paper and the blank test without adding the nucleating agent and the flocculant showed the removal rate (chemicals only) excluding the influence of the filter paper.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
 総合的な重金属除去性能を示す除去負荷量指数の結果をみると、本願発明で使用する造核剤は、凝集剤1~5より高い除去性能を示している。 Looking at the results of the removal load index indicating the overall heavy metal removal performance, the nucleating agent used in the present invention shows a higher removal performance than the flocculants 1-5.
 (3)pHの影響について
 造核剤供給手段と限外ろ過膜(UF膜)とを組み合わせた実験機を用いて、浄水を製造した。即ち、原水槽において、金属濃度を0.02mg/Lに調整した原水をそれぞれ、pHを5.5、6.5、7.5、8.5に調整した。その後、造核剤(重量平均粒子径約10nmの水酸化第二鉄のコロイド粒子の水分散物)を、造核剤貯蔵タンクから、全鉄濃度が0.12mg/L、0.36mg/L、0.6mg/Lとなるように原水に添加し、被処理液を2分間撹拌して、凝集物を発生させた。被処理液をUF膜(膜天社製、孔径:約100nm)を用いて、以下の条件で濾過した。
・膜間差圧=0.11MPa
・一次側圧力=0.24 MPa
・二次側圧力=0.13 MPa
・膜手段の濾過総面積Sに対する濾過量Vの比(V/S)=0.08m/hr
(3) About the influence of pH The purified water was manufactured using the experimental machine which combined the nucleating agent supply means and the ultrafiltration membrane (UF membrane). That is, in the raw water tank, the raw water whose metal concentration was adjusted to 0.02 mg / L was adjusted to pH 5.5, 6.5, 7.5, and 8.5, respectively. Thereafter, a nucleating agent (an aqueous dispersion of ferric hydroxide colloidal particles having a weight average particle diameter of about 10 nm) is added from the nucleating agent storage tank to a total iron concentration of 0.12 mg / L, 0.36 mg / L. , 0.6 mg / L was added to the raw water, and the liquid to be treated was stirred for 2 minutes to generate aggregates. The liquid to be treated was filtered using a UF membrane (Membrane Tensha, pore size: about 100 nm) under the following conditions.
・ Transmembrane differential pressure = 0.11 MPa
・ Primary pressure = 0.24 MPa
・ Secondary pressure = 0.13 MPa
The ratio of the filtration amount V to the total filtration area S of the membrane means (V / S) = 0.08 m / hr
 重金属としては、AsおよびPbを用い、除去率を算出した。図13は、Asについて、原水のpHと濾過処理後の浄水中の重金属濃度との関係を表すグラフである。図14は、Pbについて、原水のpHと濾過処理後の浄水中の重金属濃度との関係を示すグラフである。図13の結果から、pHが8.5で除去効果があり、またpHが8.5より低い方が、Asの除去効果が高くなることが分かる。また、図14の結果から、pHが5.5より高い方が、Pbの除去効果が高くなることが分かる。 As the heavy metal, As and Pb were used, and the removal rate was calculated. FIG. 13: is a graph showing the relationship between the pH of raw | natural water and the heavy metal density | concentration in the purified water after a filtration process about As. FIG. 14 is a graph showing the relationship between the pH of raw water and the concentration of heavy metals in purified water after filtration for Pb. From the results of FIG. 13, it can be seen that the removal effect is obtained at pH 8.5, and the removal effect of As is higher when the pH is lower than 8.5. Moreover, it can be seen from the results of FIG. 14 that the effect of removing Pb is higher when the pH is higher than 5.5.
 (4)造核剤の重量平均粒子径について
 As濃度を0.02mg/Lに調整した原水に、造核剤を、全鉄濃度が0.12mg/L、0.36mg/L、0.6mg/Lとなるように添加し、被処理液を1分間撹拌して、凝集物を発生させた。被処理液を濾過膜(AdvantecNo.2:孔径:5μm)で濾過し、除去率を算出した。造核剤としては、重量平均粒子径が15nm、25nm、50nm、160nmのものを使用した。図15は、As除去率と造核剤の重量平均粒子径との関係を示すグラフである。本発明で使用する造核剤は、重量平均粒子径が15nm~160nmの範囲で、Asについて高い除去率を示すことが分かる。
(4) About the weight average particle diameter of the nucleating agent In the raw water whose As concentration was adjusted to 0.02 mg / L, the nucleating agent was added to the total iron concentration of 0.12 mg / L, 0.36 mg / L, 0.6 mg. / L was added, and the liquid to be treated was stirred for 1 minute to generate aggregates. The liquid to be treated was filtered through a filtration membrane (Advantec No. 2: pore size: 5 μm), and the removal rate was calculated. As the nucleating agent, those having a weight average particle size of 15 nm, 25 nm, 50 nm, and 160 nm were used. FIG. 15 is a graph showing the relationship between the As removal rate and the weight average particle size of the nucleating agent. It can be seen that the nucleating agent used in the present invention exhibits a high removal rate for As when the weight average particle diameter is in the range of 15 nm to 160 nm.
 本発明のセントラル浄水装置は、小型であり、重金属イオン、ヒ素などの不純物質を効率的に除去でき、また逆洗浄効率が高い。本発明のセントラル浄水装置は、マンション、ビルなどの建物全域に浄水を供給する浄水装置として好適である。 The central water purification apparatus of the present invention is small in size, can efficiently remove impurities such as heavy metal ions and arsenic, and has high backwashing efficiency. The central water purification apparatus of this invention is suitable as a water purification apparatus which supplies purified water to the whole building, such as a condominium and a building.
1:浄水装置、3:原水供給路、5A,5B:原水分岐路、7A,7B:排出路、9A,9B:膜モジュール、11A,11B:浄水分岐路、13:浄水路、P1:原水供給手段、18:圧力計 1: Water purification device, 3: Raw water supply path, 5A, 5B: Raw water branch path, 7A, 7B: Discharge path, 9A, 9B: Membrane module, 11A, 11B: Purified water branch path, 13: Clean water path, P1: Raw water supply Means 18: Pressure gauge

Claims (12)

  1.  原水に造核剤を添加し、膜手段で濾過する生活用浄水の製造方法であって、前記造核剤として、重量平均粒子径が5nm~160nmの水酸化第二鉄のコロイド粒子の水分散物を用いて、前記原水に添加される鉄分の総質量に対する水酸化第二鉄コロイド粒子の水分散物の鉄分の質量の比率を0.9以上にすることを特徴とする生活用浄水の製造方法。 A method for producing clean water for daily life, in which a nucleating agent is added to raw water and filtered by a membrane means, wherein water dispersion of colloidal particles of ferric hydroxide having a weight average particle diameter of 5 nm to 160 nm is used as the nucleating agent The ratio of the mass of iron in the aqueous dispersion of ferric hydroxide colloidal particles to the total mass of iron added to the raw water is made 0.9 or more using Method.
  2.  前記造核剤が、原水に含まれるイオン性不純物質を捕捉して凝集物を形成し、前記凝集物を膜手段で濾過する請求項1に記載の生活用浄水の製造方法。 The method for producing purified water for daily use according to claim 1, wherein the nucleating agent captures ionic impurities contained in raw water to form aggregates, and the aggregates are filtered by a membrane means.
  3.  造核剤を添加した原水を直接膜手段に供給して濾過する請求項1または2に記載の生活用浄水の製造方法。 The method for producing purified water for daily life according to claim 1 or 2, wherein raw water added with a nucleating agent is directly supplied to a membrane means and filtered.
  4.  前記原水は、自然水または水道水であり、前記生活用浄水は、飲料水である請求項1~3のいずれか一項に記載の生活用浄水の製造方法。 The method for producing domestic purified water according to any one of claims 1 to 3, wherein the raw water is natural water or tap water, and the domestic purified water is drinking water.
  5.  前記イオン性不純物質は、重金属イオンである請求項1~4のいずれか一項に記載の生活用浄水の製造方法。 The method for producing purified water for daily use according to any one of claims 1 to 4, wherein the ionic impurity is a heavy metal ion.
  6.  前記膜手段として、限外濾過膜(UF膜)または精密濾過膜(MF膜)を用いる請求項1~5のいずれか一項に記載の生活用浄水の製造方法。 The method for producing purified water for daily use according to any one of claims 1 to 5, wherein an ultrafiltration membrane (UF membrane) or a microfiltration membrane (MF membrane) is used as the membrane means.
  7.  原水に対する造核剤の添加量は、全鉄濃度で0.12mg/L以上、9mg/L以下である請求項1~6のいずれか一項に記載の生活用浄水の製造方法。 The method for producing clean water for daily use according to any one of claims 1 to 6, wherein the amount of the nucleating agent added to the raw water is 0.12 mg / L or more and 9 mg / L or less in terms of total iron concentration.
  8.  前記膜手段の膜間差圧を0.03MPa超、0.45MPa以下とする請求項1~7のいずれか一項に記載の生活用浄水の製造方法。 The method for producing clean water for daily use according to any one of claims 1 to 7, wherein the transmembrane pressure difference of the membrane means is more than 0.03 MPa and 0.45 MPa or less.
  9.  前記膜手段の一次側圧力を0.08MPa~0.50MPaとする請求項1~8のいずれか一項に記載の生活用浄水の製造方法。 The method for producing water for daily life according to any one of claims 1 to 8, wherein the primary pressure of the membrane means is 0.08 MPa to 0.50 MPa.
  10.  前記膜手段の二次側圧力を0.05MPa~0.30MPaとする請求項1~9のいずれか一項に記載の生活用浄水の製造方法。 The method for producing purified water for daily use according to any one of claims 1 to 9, wherein the secondary pressure of the membrane means is 0.05 MPa to 0.30 MPa.
  11.  濾過方式が、全量濾過方式である請求項1~10のいずれか一項に記載の生活用浄水の製造方法。 The method for producing clean water for daily use according to any one of claims 1 to 10, wherein the filtration method is a total amount filtration method.
  12.  請求項1~11のいずれか一項に記載の生活用浄水の製造方法に使用される装置であって、
     原水供給路と、
     原水供給路に配置され、原水を送液する原水供給手段と、
     前記原水供給路を少なくとも2以上に分岐する複数の原水分岐路と、
     前記複数の原水分岐路に配置され、原水を濾過する複数の膜手段を備える膜モジュールと、
     前記複数の膜モジュールの一次側に接続する排出路と、
     前記複数の膜モジュールの二次側に接続する複数の浄水分岐路と、
     前記複数の浄水分岐路が合流する浄水路とを有しており、
     前記膜モジュールの一次側で、原水に造核剤を供給する手段を備え、造核剤の添加によって発生する凝集物を沈殿させて分離する分離槽を備えないことを特徴とする生活用浄水の製造装置。
    An apparatus used in the method for producing water for daily life according to any one of claims 1 to 11,
    Raw water supply channel,
    Raw water supply means that is disposed in the raw water supply path and feeds raw water,
    A plurality of raw water branch paths that branch the raw water supply path into at least two or more;
    A membrane module that is disposed in the plurality of raw water branches and includes a plurality of membrane means for filtering raw water;
    A discharge path connected to a primary side of the plurality of membrane modules;
    A plurality of water purification branches connected to the secondary side of the plurality of membrane modules;
    A plurality of water purifying branches, and
    Purifying water for daily use comprising a means for supplying a nucleating agent to the raw water on the primary side of the membrane module, and no separation tank for precipitating and separating aggregates generated by the addition of the nucleating agent. Manufacturing equipment.
PCT/JP2014/077499 2014-10-16 2014-10-16 Production method for purified daily life water and production apparatus for purified daily life water WO2016059691A1 (en)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08206663A (en) * 1995-02-03 1996-08-13 Suido Kiko Kaisha Ltd Removal of arsenic by permeable membrane in water purifying treatment
JP2001286872A (en) * 2000-04-05 2001-10-16 Kurita Water Ind Ltd Operation method of flocculating treatment device and flocculating treatment device
JP2002172395A (en) * 2000-12-05 2002-06-18 Nec Environment Eng Ltd Method for iron hydroxide flocculation and sedimentation treatment of thick inorganic component- containing wastewater
JP2002320979A (en) * 2001-04-27 2002-11-05 Sharp Corp Method and system for treating metal-containing drainage
JP2010247057A (en) * 2009-04-15 2010-11-04 Kurosaki:Kk Water purification method combining fine particle-making method and membrane separation method
JP2012196657A (en) * 2011-03-22 2012-10-18 Kurosaki:Kk Treatment method of wastewater containing phenols
JP2014057926A (en) * 2012-09-19 2014-04-03 Takagi Co Ltd Water purifier and production method of purified water

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08206663A (en) * 1995-02-03 1996-08-13 Suido Kiko Kaisha Ltd Removal of arsenic by permeable membrane in water purifying treatment
JP2001286872A (en) * 2000-04-05 2001-10-16 Kurita Water Ind Ltd Operation method of flocculating treatment device and flocculating treatment device
JP2002172395A (en) * 2000-12-05 2002-06-18 Nec Environment Eng Ltd Method for iron hydroxide flocculation and sedimentation treatment of thick inorganic component- containing wastewater
JP2002320979A (en) * 2001-04-27 2002-11-05 Sharp Corp Method and system for treating metal-containing drainage
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