WO2019208532A1 - Water treatment method and water treatment apparatus - Google Patents

Water treatment method and water treatment apparatus Download PDF

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Publication number
WO2019208532A1
WO2019208532A1 PCT/JP2019/017115 JP2019017115W WO2019208532A1 WO 2019208532 A1 WO2019208532 A1 WO 2019208532A1 JP 2019017115 W JP2019017115 W JP 2019017115W WO 2019208532 A1 WO2019208532 A1 WO 2019208532A1
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water
cationic polymer
treated
membrane separation
inorganic flocculant
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PCT/JP2019/017115
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French (fr)
Japanese (ja)
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貴子 岩見
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栗田工業株式会社
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D21/00—Separation of suspended solid particles from liquids by sedimentation
    • B01D21/01—Separation of suspended solid particles from liquids by sedimentation using flocculating agents
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/58—Multistep processes
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
    • C02F1/56—Macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/10—Metal compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers

Definitions

  • the present invention relates to a reduced water treatment method and a water treatment apparatus.
  • Patent Document 1 describes a technique for aggregating high-pH or high-alkaliness water to be treated by adding a cationic polymer prior to the addition of an inorganic flocculant.
  • organic substances and SS in the raw water first react with the cationic polymer, the required amount of the cationic polymer is large, leading to an increase in cost.
  • Patent Document 2 discloses a technique in which an inorganic flocculant and a polymer flocculant are added and agglomeration treatment is performed, and then the inorganic flocculant is added again before solid-liquid separation. In this method, the flocculant is added many times, and the apparatus is complicated and the operation becomes complicated.
  • Patent Document 3 discloses a method of using an inorganic flocculant prior to the addition of particles made of a cationic polymer that is substantially insoluble in water.
  • the aggregated flocs containing water-insoluble particles become coarse, causing turbid contamination in the membrane separation apparatus used for solid-liquid separation.
  • dissolve in water settles in a stationary state, it is necessary to always stir the inside of a chemical
  • the present inventor first reacted an organic substance or SS in raw water with an inorganic flocculant, and then added a water-soluble cationic polymer having a specific molecular weight to disperse the inorganic flocculant colloid and fine floc that are dispersed.
  • Cationic polymer can be reacted efficiently, and even if the membrane is separated directly with a membrane separator after addition of the cationic polymer, the membrane separator is not contaminated, and the amount of coagulant used can be reduced. I found out.
  • the gist of the present invention is as follows.
  • a water treatment method in which an inorganic flocculant is added to water to be treated and then agglomerated, and then membrane separation is performed with a membrane separation apparatus, the inorganic flocculant is added to the water to be treated, and then the mass average molecular weight is 100,000 to 8 million.
  • a water treatment method comprising: adding a water-soluble cationic polymer to agglomerate, and subjecting the agglomerated water to membrane separation directly with a membrane separator.
  • the treated water is industrial water, city water, well water, industrial wastewater, or biologically treated water containing any of phosphorus, biological metabolites, organic acids having a chelating effect, and inorganic carbon.
  • the amount of the cationic polymer necessary for neutralizing the charge of the water to be treated is determined as the cation consumption A by titrating the water to be treated with the cationic polymer by the streaming potential method.
  • the cationic polymer addition amount and the inorganic flocculant addition amount are controlled such that the cation consumption amount A and the concentration of the inorganic flocculant and the cationic polymer satisfy the following relational expression (I): [1]
  • First coagulation treatment means for adding an inorganic coagulant to the water to be treated, and water-soluble cations having a mass average molecular weight of 100,000 to 8 million in the aggregation treatment water of the first coagulation treatment means
  • a water treatment apparatus comprising: a second agglomeration treatment unit for adding a functional polymer to agglomerate, and a membrane separation device for directly separating the agglomerated water of the second agglomeration treatment unit.
  • the treated water is industrial water, city water, well water, industrial wastewater, or biologically treated water containing wastewater containing any of phosphorus, biological metabolites, chelating organic acids, and inorganic carbon.
  • the amount of the cationic polymer necessary for neutralizing the charge of the water to be treated is determined as the cation consumption A by titrating the water to be treated with the cationic polymer by the streaming potential method.
  • the inorganic flocculant and the addition concentration of the cationic polymer further have means for controlling the addition amount of the cationic polymer and the addition amount of the inorganic flocculant so that the following relational expression (I) is satisfied: [6] The water treatment device according to any one of [9].
  • the amount of the flocculant used can be reduced while preventing contamination of the membrane separator.
  • the water treatment method of the present invention is a water treatment method in which an inorganic flocculant is added to the water to be treated, and then the membrane is separated by a membrane separation apparatus. It is characterized in that 100,000 to 8 million water-soluble cationic polymers are added and subjected to agglomeration treatment, and the agglomerated water is directly subjected to membrane separation with a membrane separator.
  • the water treatment apparatus of the present invention includes a first aggregating treatment means for adding an inorganic flocculant to the water to be treated and aggregating treatment water of the first aggregating treatment means, and a mass average molecular weight of 100,000 to 8 million. And a membrane separation device for directly performing membrane separation of the agglomerated water of the second agglomeration treatment means.
  • an inorganic flocculant is first added to the water to be treated to react the organic matter or SS in the water to be treated with the inorganic flocculant, and then the cationic polymer is added. Colloids and fine flocs can be reacted efficiently with cationic polymers. Even if the membrane is separated directly with a membrane separator after the addition of the cationic polymer, the membrane separator is not contaminated. Reduction is also possible.
  • a cationic polymer If a cationic polymer is added before the inorganic flocculant, the cationic polymer reacts with anion components such as SS and organic matter in the raw water and is consumed. This increases the amount of cationic polymer required to react with the dispersed inorganic flocculant colloid as compared to adding the cationic polymer after the inorganic flocculant.
  • the ratio of the addition amount of the cationic polymer / the addition amount of the inorganic flocculant becomes a certain value or more, the aggregated floc is easily adsorbed on the separation membrane and easily contaminates the membrane. Therefore, in the present invention, the cationic polymer is added after the inorganic flocculant is added.
  • the cationic polymer used in the present invention has a relatively large mass average molecular weight of 100,000 or more, the aggregated floc is unlikely to cause membrane clogging, as shown in Examples described later. Since the cationic polymer used in the present invention has a mass average molecular weight of 8 million or less and is water-soluble, aggregated flocs are difficult to deposit in the membrane module. For this reason, it is possible to prevent contamination in the membrane separation apparatus and continue the treatment stably over a long period of time.
  • the amount of the inorganic flocculant added can be reduced by the combined use of the inorganic flocculant and the cationic polymer. At that time, the cationic polymer is added after the inorganic flocculant. The amount added can be reduced, and as a result, the total amount of flocculant used can be reduced.
  • the water to be treated to be treated in the present invention is not particularly limited, but the present invention provides phosphorus, a biological metabolite, an organic acid having a chelating action, which is difficult to obtain a sufficient flocculating effect only with an inorganic flocculant, Alternatively, it is effective for the treatment of biological water such as industrial water, city water, well water, industrial wastewater, and wastewater containing inorganic carbon.
  • organic acids having a chelating action examples include citric acid, formic acid, succinic acid, acetic acid and butyric acid. These organic acids are used, for example, in a plating process in a semiconductor manufacturing process, and act as a complex ion forming agent or a dispersing agent for an inorganic flocculant when the waste water is treated. In such agglomeration of wastewater containing an organic acid, the higher the aggregation pH, the higher the complex ion forming ability of the organic acid, and the agglomerated state deteriorates.
  • the agglomeration pH becomes high is, for example, when the agglomeration is performed for the purpose of treating heavy metals such as Cu and Mn, or when the optimum agglomeration pH in the TOC removal in the raw water is 6 or more, the inorganic flocculant is polychlorinated. This is the case where aluminum is used.
  • the inorganic flocculant added to the water to be treated it is preferable to use an iron-based or aluminum-based inorganic flocculant capable of forming flocs in a wide pH range.
  • the iron-based inorganic flocculant include ferric chloride, ferric sulfate, polyferric chloride, and polyferric sulfate.
  • the aluminum-based inorganic flocculant include polyaluminum chloride and aluminum sulfate.
  • ferric chloride which is an iron-based inorganic flocculant, is preferable from the viewpoints of the aggregation effect and cost.
  • These inorganic flocculants may be used individually by 1 type, and 2 or more types may be mixed and used for them.
  • the amount of the inorganic flocculant added to the water to be treated varies depending on the quality of the water to be treated, the type of inorganic flocculant used, the quality of the water to be treated, etc., but the amount of active ingredient is in the range of 2 to 100 mg / L. It is preferable that
  • the inorganic flocculant has a suitable flocculation treatment pH range depending on the type thereof.
  • the pH is preferably about 5 to 6
  • the pH is preferably about 6 to 7. . Therefore, it is preferable to adjust the pH to a suitable pH range by adding an acid or an alkali as necessary.
  • rapid stirring is preferably performed for about 2 to 10 minutes in order to sufficiently react the organic matter or SS in the water to be treated with the inorganic flocculant.
  • rapid stirring refers to about 100 to 200 rpm as the rotational speed
  • slow stirring refers to about 20 to 100 rpm as the rotational speed
  • the cationic polymer used in the present invention is a water-soluble one having a mass average molecular weight of 100,000 to 8 million.
  • Water-soluble means that the solubility in water is 1 g or more / 100 g of water (20 ° C.).
  • the “cationic polymer” is one having a positive colloidal equivalent.
  • the colloidal equivalent is preferably 1.0 to 6.0 meq / g.
  • the colloidal equivalent is measured by the streaming potential method after titration with 1 / 400N PVSK (polyvinyl potassium sulfate).
  • the mass average molecular weight of the cationic polymer is a value of a mass average molecular weight measured by a chromatography method (GPC method).
  • the weight average molecular weight of the cationic polymer is less than 100,000, the aggregated flocs that are formed become fine, and membrane clogging is likely to occur.
  • the mass average molecular weight of the cationic polymer exceeds 8 million, the aggregated flocs become too coarse and are easily deposited in the membrane module. Therefore, the weight average molecular weight of the cationic polymer used in the present invention is in the range of 100,000 to 8 million, preferably 200,000 to 1 million.
  • the cationic polymer is not particularly limited as long as it is water-soluble having the above-described mass average molecular weight, but a copolymer of a cationic monomer and a nonionic monomer such as acrylamide can be suitably used. .
  • cationic monomer for example, dimethylaminoethyl acrylate or dimethylaminoethyl methacrylate acid salt or quaternary ammonium salt thereof, dimethylaminopropyl acryamide or dimethylaminopropyl methacrylate acid acid salt or quaternary ammonium salt is preferably used. However, it is not limited to these.
  • quaternary ammonium salt a quaternary ammonium salt such as methyl chloride or ethyl chloride can be used.
  • cationic polymer one kind may be used alone, or two or more kinds may be mixed and used.
  • the amount of the cationic polymer added to the agglomerated treated water with inorganic coagulant depends on the quality of the water to be treated or the inorganic agglomerated treated water and the type of the cationic polymer used.
  • the amount of active ingredient is preferably in the range of 0.1 to 5 mg / L, although it varies depending on the type of active ingredient.
  • agglomerated water obtained by adding a cationic polymer to the inorganic agglomerated water (hereinafter sometimes referred to as “cation agglomerated water”) is directly subjected to membrane separation by a membrane separation device.
  • Direct membrane separation means that water is directly supplied to the membrane separation apparatus without adding a flocculant to the cation flocculation treated water or performing solid-liquid separation using a precipitation tank or the like.
  • the membrane separator used in the present invention is not particularly limited in its membrane material, membrane type and structure.
  • As the membrane separator an MF membrane separator or a UF membrane separator is preferably used.
  • the pore size of the UF membrane and MF membrane is preferably 0.2 ⁇ m or less, for example, about 0.1 to 0.01 ⁇ m.
  • the membrane separation method using the membrane separator there is no particular limitation on the membrane separation method using the membrane separator.
  • the dead end water flow method is used, but a cross flow water flow method may be used.
  • the treated water obtained by membrane separation by the above membrane separator is of high quality from which organic substances, SS, etc. are sufficiently removed, and can be used as industrial water or discharged as it is, but if necessary
  • RO membrane treatment may be performed by a reverse osmosis (RO) membrane separation apparatus.
  • RO reverse osmosis
  • the cation consumption A of the water to be treated is obtained in this way, and the inorganic flocculant and the cationic polymer are added so that the added concentration of the inorganic flocculant and the cationic polymer satisfies the following relational expression (I). It is preferable to control the addition amount.
  • Cation consumption A ⁇ ⁇ Cationic polymer addition concentration (mg / L) + Inorganic flocculant addition concentration (mg / L) ⁇ ⁇ (I)
  • ⁇ is a safety factor taking into account fluctuations in water quality, and is usually about 0.6 to 0.9.
  • ⁇ is a coefficient for converting the cation amount of the inorganic flocculant used to the cation amount of the cationic polymer, and is obtained by titration using a flow ammeter.
  • Control of the addition amount of the cationic polymer and the inorganic flocculant is performed by inputting the cation consumption A of the water to be treated obtained in advance, the conversion coefficient ⁇ of the inorganic flocculant to be used, and the preset safety coefficient ⁇ . It can be performed automatically by means.
  • inorganic flocculants and cationic polymers used in the following examples and comparative examples are as follows.
  • Inorganic flocculant ferric chloride
  • Cationic polymer dimethylaminoethyl acrylate / methyl chloride quaternary salt / acrylamide copolymer having a mass average molecular weight of 50,000, 100,000, 200,000, 700,000, 1 million, 8 million or 10 million Combined (colloid equivalent 2.5-3.0 meq / g)
  • an external pressure type mini-module test apparatus shown in FIGS. 1A and 1B (external pressure type hollow fiber UF membrane, pore diameter: 0.02 ⁇ m, membrane length: 7.5 cm, membrane area: 10.6 cm) 2 , film material polyvinylidene fluoride) was used.
  • 1 is a hollow fiber membrane
  • 2 is a potting agent
  • 3 is a raw water inlet
  • 4 is a drain.
  • Reference numeral 5 denotes a module housing in which the hollow fiber membrane 1 is loaded. The raw water is introduced into the housing 5 from the inlet 3, and the permeated water that has permeated through the hollow fiber membrane 1 is taken out from the inside of the hollow fiber membrane 1 to the outside of the housing 5.
  • V 2 During wastewater, while stopping the pump P, and valve V 1, V 2 opens, the valve V 3 is closed, the air air into the pipe 11 from the pipe 11A, the discharge of water of the pipe 12 from the module 10 Let Air from the pipes 11A and 13A was supplied at 0.15 MPa.
  • the valve V 2 At the time of water filling, the valve V 2 is opened, the valves V 1 and V 3 are closed, the pump P is operated, and the water in the water supply tank 6 is introduced into the module 10.
  • PI is a pressure gauge.
  • the obtained agglomerated water was passed through an external pressure mini-module test apparatus shown in FIGS. 1 (a) and 1 (b) for 48 hours. Measured with a pressure gauge Pl provided on the pipe 11 after passing through water and backwashing every 30 minutes with a flux of 4 m 3 / m 2 / d (30 seconds), then draining (30 seconds), and then watering (30 seconds). The rate of increase in transmembrane pressure was investigated.
  • the SS concentration of the feed water (flocculated treated water subjected to membrane separation treatment) and the amount of SS in the wastewater obtained by passing water for 48 hours were measured, and the SS residual ratio in the module was calculated by the following formula. .
  • the feed water SS concentration and the amount of SS in the wastewater were measured as the dry weight of the filtered material obtained when these waters were filtered through glass filter paper having a diameter of 47 mm and a pore diameter of 1 ⁇ m. The results are shown in Table 1.
  • Table 1 shows the following.
  • the flocs became fine, so that the membrane was likely to be clogged and the rate of increase in the differential pressure tended to increase (Comparative Example 1).
  • the molecular weight of the cationic polymer is increased, flocs are coarsened, so that they are easily deposited in the module, and the SS residual ratio is increased (Comparative Example 2). From these results, it is understood that the proper mass average molecular weight of the cationic polymer is 100,000 to 8 million, and desirably 200,000 to 1 million from the viewpoint of membrane contamination.
  • Example I Using the following inorganic flocculant and cationic polymer, an experiment was conducted to examine the effect of the addition order of the inorganic flocculant and the cationic polymer.
  • Inorganic flocculant Ferric chloride
  • Cationic polymer Polydiallyldimethylammonium chloride having a mass average molecular weight of 200,000 (colloid equivalent 5.9 meq / g, intrinsic viscosity 0.75 dg / L)
  • Test water Model water to which phosphoric acid (phosphoric acid was added for the purpose of dispersing the inorganic flocculant) was added to domestic industrial water so as to be 6 mg / L asP was used.
  • the test method is as follows.
  • inorganic flocculant (ferric chloride) as a 38% aqueous solution and 0.6 mg / L of cationic polymer (as pure component) are added to the test water, and the pH is adjusted to 5 using a pH adjuster (sodium hydroxide).
  • No. 5 was subjected to flocculation treatment, and the obtained flocculation water was designated After filtration through 5A filter paper, the filtrate was filtered under reduced pressure at ⁇ 500 mmHg using a cellulose acetate membrane filter having a diameter of 25 mm and a pore diameter of 0.45 ⁇ m.
  • the time required to filter the first 150 mL is T1 (seconds)
  • the time required to filter the next 150 mL is T2 (seconds)
  • the aggregation treatment procedure using the inorganic flocculant and the cationic polymer was as follows for each example.
  • Experimental Example I-1 Additional cationic flocculant after addition of inorganic flocculant: Inorganic flocculant was added while rapidly stirring the test water at 150 rpm, then adjusted to pH 5.5 using a pH adjuster, and further for 5 minutes While stirring rapidly, the cationic polymer was added with rapid stirring and reacted for 5 minutes, and then the mixture was gently stirred at 50 rpm for another 5 minutes for aggregation treatment.
  • Example II Using the same inorganic flocculant and cationic polymer as those used in Experimental Example I, an experiment was conducted to examine the effect of the cationic polymer on wastewater containing an organic acid having a chelating effect.
  • the wastewater from the plating process of a domestic semiconductor factory dissolved organic matter concentration including organic acid 10 to 20 mg / L, copper concentration 6 mg / L was used.
  • the test method is as follows.
  • Aggregation treatment was performed for the purpose of removing copper in the test water.
  • 500 mg / L of an inorganic flocculant (ferric chloride) as a 38% aqueous solution was added while rapidly stirring the test water at 150 rpm, and then adjusted to pH 9 using a pH adjuster (sodium hydroxide).
  • 0-5 mg / L of a cationic polymer (addition amount shown in Table 2 as a pure content) was added with rapid stirring and reacted for 5 minutes. Thereafter, the flocs were grown by gently stirring at 50 rpm for another 5 minutes.
  • the obtained agglomerated treated water was No.
  • the copper ion concentration in the filtrate was measured. It means that the lower the copper ion concentration, the more effectively the aggregation treatment is performed and the better the aggregation state.
  • the results are shown in Table 2.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Water Supply & Treatment (AREA)
  • Environmental & Geological Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
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Abstract

A water treatment method in which an inorganic flocculant is added to water of interest to perform a flocculation treatment of the water and then the water is subjected to membrane separation using a membrane separation apparatus, wherein the inorganic flocculant is added to the water, then the flocculation treatment is performed by adding a water-soluble cationic polymer having a mass average molecular weight of 100,000 to 8,000,000 to the water, and then the water that has undergone the flocculation treatment is directly subjected to membrane separation using a membrane separation apparatus.

Description

水処理方法及び水処理装置Water treatment method and water treatment apparatus
　本発明は、被処理水に無機凝集剤を添加して凝集処理した後、凝集処理水を膜分離装置で膜分離する水処理において、膜分離装置の汚染を防止すると共に、凝集剤使用量を低減する水処理方法及び水処理装置に関する。 In the water treatment in which an inorganic flocculant is added to the water to be treated and then agglomeration is performed, and then the agglomerated water is subjected to membrane separation with a membrane separator, the membrane separator is prevented from being contaminated and the amount of the flocculant used is reduced. The present invention relates to a reduced water treatment method and a water treatment apparatus.
　工業用水、市水、井水、工業排水などの被処理水を処理する方法として、原水中の有機物並びに濁質（ＳＳ）を除去する目的で無機凝集剤で凝集処理した後に、凝集処理水を沈殿分離装置や浮上分離装置、或いは精密濾過膜（ＭＦ膜）モジュール又は限外濾過膜（ＵＦ膜）モジュールによる膜分離装置によって固液分離して清澄水を得る方法がある。しかし、この方法では、例えば被処理水が高ｐＨないしは高アルカリ度である場合や、高濃度のリンや生物代謝物を含む場合、これらの物質が無機凝集剤を分散させるため、無機凝集剤のみの凝集処理では大量の無機凝集剤が必要となり、汚泥発生量の増加につながる。さらには、無機凝集剤濃度が増加することによって、固液分離に用いた膜分離装置の洗浄頻度の増加につながる。 As a method of treating treated water such as industrial water, city water, well water, industrial wastewater, etc., after coagulating with an inorganic flocculant for the purpose of removing organic matter and suspended matter (SS) in raw water, There is a method of obtaining clear water by solid-liquid separation using a sedimentation separator, a flotation separator, a membrane separator using a microfiltration membrane (MF membrane) module or an ultrafiltration membrane (UF membrane) module. However, in this method, for example, when the water to be treated has a high pH or high alkalinity or contains a high concentration of phosphorus or a biological metabolite, these substances disperse the inorganic flocculant. In the coagulation treatment, a large amount of inorganic coagulant is required, leading to an increase in the amount of sludge generated. Furthermore, an increase in the concentration of the inorganic flocculant leads to an increase in the cleaning frequency of the membrane separation apparatus used for solid-liquid separation.
　無機凝集剤のみでは凝集処理が困難な被処理水に対して、無機凝集剤とともにカチオン性ポリマーを用いる方法がある。例えば、特許文献１には、無機凝集剤の添加に先立ちカチオン性ポリマーを添加することで、高ｐＨあるいは高アルカリ度の被処理水を凝集処理する技術が記載されている。本方法では原水中の有機物やＳＳが最初にカチオン性ポリマーと反応するため、カチオン性ポリマーの必要添加量が多く、コスト増加につながる。 There is a method of using a cationic polymer together with an inorganic flocculant for water to be treated, which is difficult to flocculate only with an inorganic flocculant. For example, Patent Document 1 describes a technique for aggregating high-pH or high-alkaliness water to be treated by adding a cationic polymer prior to the addition of an inorganic flocculant. In this method, since organic substances and SS in the raw water first react with the cationic polymer, the required amount of the cationic polymer is large, leading to an increase in cost.
　特許文献２には、無機凝集剤と高分子凝集剤とを添加して凝集処理した後、固液分離する前に再び無機凝集剤を添加する技術が示されている。この方法では凝集剤の添加回数が多く、装置が複雑で操作が煩雑になる。 Patent Document 2 discloses a technique in which an inorganic flocculant and a polymer flocculant are added and agglomeration treatment is performed, and then the inorganic flocculant is added again before solid-liquid separation. In this method, the flocculant is added many times, and the apparatus is complicated and the operation becomes complicated.
　特許文献３には、実質的に水に溶解しないカチオン性ポリマーからなる粒子を用い、その添加に先立ち無機凝集剤を添加する方法が示されている。この方法では、非水溶性の粒子を含む凝集フロックが粗大になるため、固液分離に用いる膜分離装置内に濁質汚染を引き起こす。また、水に溶解しないポリマーは静置状態で沈降するため、薬品タンク内を常に攪拌する必要があり、薬注設備が複雑になる上に設備維持コストも増大する。 Patent Document 3 discloses a method of using an inorganic flocculant prior to the addition of particles made of a cationic polymer that is substantially insoluble in water. In this method, the aggregated flocs containing water-insoluble particles become coarse, causing turbid contamination in the membrane separation apparatus used for solid-liquid separation. Moreover, since the polymer which does not melt | dissolve in water settles in a stationary state, it is necessary to always stir the inside of a chemical | medical agent tank, a chemical injection equipment becomes complicated, and equipment maintenance cost also increases.
特開２０１７－１４０５７７号公報JP 2017-140577 A 特開平１１－７７０６２号公報JP 11-77062 A 特開２００９－２４０９７４号公報JP 2009-240974 A
　本発明は、被処理水に無機凝集剤を添加して凝集処理した後、凝集処理水を膜分離装置で膜分離する水処理において、膜分離装置の汚染を防止すると共に、凝集剤使用量を低減する水処理方法及び水処理装置を提供することを目的とする。 In the water treatment in which an inorganic flocculant is added to the water to be treated and then agglomeration is performed, and then the agglomerated water is subjected to membrane separation with a membrane separator, the membrane separator is prevented from being contaminated and the amount of the flocculant used is reduced. It aims at providing the water treatment method and water treatment apparatus which reduce.
　本発明者は、最初に原水中の有機物やＳＳと無機凝集剤とを反応させた後に、特定の分子量の水溶性のカチオン性ポリマーを添加することで、分散する無機凝集剤コロイドや微細フロックとカチオン性ポリマーとを効率的に反応させることができ、カチオン性ポリマー添加後直接膜分離装置で膜分離しても膜分離装置を汚染することなく、また、凝集剤使用量の低減も可能であることを見出した。
　本発明は以下を要旨とする。 The present inventor first reacted an organic substance or SS in raw water with an inorganic flocculant, and then added a water-soluble cationic polymer having a specific molecular weight to disperse the inorganic flocculant colloid and fine floc that are dispersed. Cationic polymer can be reacted efficiently, and even if the membrane is separated directly with a membrane separator after addition of the cationic polymer, the membrane separator is not contaminated, and the amount of coagulant used can be reduced. I found out.
The gist of the present invention is as follows.
［１］　被処理水に無機凝集剤を添加して凝集処理した後に膜分離装置で膜分離する水処理方法において、被処理水に無機凝集剤を添加した後、質量平均分子量１０万～８００万の水溶性のカチオン性ポリマーを添加して凝集処理し、凝集処理水を直接膜分離装置で膜分離することを特徴とする水処理方法。 [1] In a water treatment method in which an inorganic flocculant is added to water to be treated and then agglomerated, and then membrane separation is performed with a membrane separation apparatus, the inorganic flocculant is added to the water to be treated, and then the mass average molecular weight is 100,000 to 8 million. A water treatment method comprising: adding a water-soluble cationic polymer to agglomerate, and subjecting the agglomerated water to membrane separation directly with a membrane separator.
［２］　前記被処理水がリン、生物代謝物、キレート効果を有する有機酸、及び無機炭素のいずれかを含む、工業用水、市水、井水、工業排水、或いは排水の生物処理水である［１］に記載の水処理方法。 [2] The treated water is industrial water, city water, well water, industrial wastewater, or biologically treated water containing any of phosphorus, biological metabolites, organic acids having a chelating effect, and inorganic carbon. The water treatment method according to [1].
［３］　前記膜分離装置が、精密濾過膜分離装置又は限外濾過膜分離装置である［１］又は［２］に記載の水処理方法。 [3] The water treatment method according to [1] or [2], wherein the membrane separation device is a microfiltration membrane separation device or an ultrafiltration membrane separation device.
［４］　前記膜分離装置で得られた処理水を、さらに逆浸透膜処理する［１］～［３］のいずれかに記載の水処理方法。 [4] The water treatment method according to any one of [1] to [3], wherein the treated water obtained by the membrane separation device is further subjected to a reverse osmosis membrane treatment.
［５］　流動電位法により前記被処理水を前記カチオン性ポリマーで滴定することで、該被処理水の電荷を中和するのに必要な該カチオン性ポリマーの必要量をカチオン消費量Ａとして求め、該カチオン消費量Ａと前記無機凝集剤及び該カチオン性ポリマーの添加濃度とが下記関係式（Ｉ）を満たすように、該カチオン性ポリマーの添加量と該無機凝集剤の添加量を制御する［１］～［４］のいずれかに記載の水処理方法。
　カチオン消費量Ａ×α＝
　　カチオン性ポリマー添加濃度（ｍｇ／Ｌ）＋無機凝集剤添加濃度（ｍｇ／Ｌ）×β　　…（Ｉ）
　　α：水質変動を加味した安全係数
　　β：無機凝集剤のカチオン量をカチオン性ポリマーのカチオン量に換算する係数 [5] The amount of the cationic polymer necessary for neutralizing the charge of the water to be treated is determined as the cation consumption A by titrating the water to be treated with the cationic polymer by the streaming potential method. The cationic polymer addition amount and the inorganic flocculant addition amount are controlled such that the cation consumption amount A and the concentration of the inorganic flocculant and the cationic polymer satisfy the following relational expression (I): [1] The water treatment method according to any one of [4].
Cation consumption A × α =
Cationic polymer addition concentration (mg / L) + Inorganic flocculant addition concentration (mg / L) × β (I)
α: Safety factor taking into account fluctuations in water quality β: Factor for converting the cation amount of the inorganic flocculant into the cation amount of the cationic polymer
［６］　被処理水に無機凝集剤を添加して凝集処理する第１の凝集処理手段と、該第１の凝集処理手段の凝集処理水に質量平均分子量１０万～８００万の水溶性のカチオン性ポリマーを添加して凝集処理する第２の凝集処理手段と、該第２の凝集処理手段の凝集処理水を直接膜分離する膜分離装置とを有することを特徴とする水処理装置。 [6] First coagulation treatment means for adding an inorganic coagulant to the water to be treated, and water-soluble cations having a mass average molecular weight of 100,000 to 8 million in the aggregation treatment water of the first coagulation treatment means A water treatment apparatus comprising: a second agglomeration treatment unit for adding a functional polymer to agglomerate, and a membrane separation device for directly separating the agglomerated water of the second agglomeration treatment unit.
［７］　前記被処理水がリン、生物代謝物、キレート作用を有する有機酸、及び無機炭素のいずれかを含む、工業用水、市水、井水、工業排水、或いは排水の生物処理水である［６］に記載の水処理装置。 [7] The treated water is industrial water, city water, well water, industrial wastewater, or biologically treated water containing wastewater containing any of phosphorus, biological metabolites, chelating organic acids, and inorganic carbon. The water treatment device according to [6].
［８］　前記膜分離装置が、精密濾過膜分離装置又は限外濾過膜分離装置である［６］又は［７］に記載の水処理装置。 [8] The water treatment device according to [6] or [7], wherein the membrane separation device is a microfiltration membrane separation device or an ultrafiltration membrane separation device.
［９］　前記膜分離装置で得られた処理水を処理する逆浸透膜分離装置を更に有する［６］～［８］のいずれかに記載の水処理装置。 [9] The water treatment device according to any one of [6] to [8], further comprising a reverse osmosis membrane separation device for treating treated water obtained by the membrane separation device.
［１０］　流動電位法により前記被処理水を前記カチオン性ポリマーで滴定することで、該被処理水の電荷を中和するのに必要な該カチオン性ポリマーの必要量をカチオン消費量Ａとして求め、前記無機凝集剤及び該カチオン性ポリマーの添加濃度とが、下記関係式（Ｉ）を満たすように、該カチオン性ポリマーの添加量と該無機凝集剤の添加量を制御する手段を更に有する［６］～［９］のいずれかに記載の水処理装置。
　カチオン消費量Ａ×α＝
　　カチオン性ポリマー添加濃度（ｍｇ／Ｌ）＋無機凝集剤添加濃度（ｍｇ／Ｌ）×β　　…（Ｉ）
　　α：水質変動を加味した安全係数
　　β：無機凝集剤のカチオン量をカチオン性ポリマーのカチオン量に換算する係数 [10] The amount of the cationic polymer necessary for neutralizing the charge of the water to be treated is determined as the cation consumption A by titrating the water to be treated with the cationic polymer by the streaming potential method. The inorganic flocculant and the addition concentration of the cationic polymer further have means for controlling the addition amount of the cationic polymer and the addition amount of the inorganic flocculant so that the following relational expression (I) is satisfied: [6] The water treatment device according to any one of [9].
Cation consumption A × α =
Cationic polymer addition concentration (mg / L) + Inorganic flocculant addition concentration (mg / L) × β (I)
α: Safety factor taking into account fluctuations in water quality β: Factor for converting the cation amount of the inorganic flocculant into the cation amount of the cationic polymer
　本発明によれば、被処理水を凝集処理して膜分離装置で膜分離する水処理において、膜分離装置の汚染を防止した上で、凝集剤使用量を低減することができる。 According to the present invention, in the water treatment in which the water to be treated is agglomerated and membrane-separated by the membrane separator, the amount of the flocculant used can be reduced while preventing contamination of the membrane separator.
実施例で用いた外圧式ミニモジュール試験装置を示す構成図である。It is a block diagram which shows the external pressure type | mold mini-module test apparatus used in the Example. 実験例Ｉにおけるカチオン性ポリマーと無機凝集剤の添加順の凝集処理水質（ＭＦＦ）に及ぼす影響を示すグラフである。It is a graph which shows the influence which it has on the aggregation process water quality (MFF) of the addition order of the cationic polymer and the inorganic flocculant in Experimental example I.
　以下に本発明の水処理方法及び水処理装置の実施の形態を詳細に説明する。 Hereinafter, embodiments of a water treatment method and a water treatment apparatus of the present invention will be described in detail.
　本発明の水処理方法は、被処理水に無機凝集剤を添加して凝集処理した後に膜分離装置で膜分離する水処理方法において、被処理水に無機凝集剤を添加した後、質量平均分子量１０万～８００万の水溶性のカチオン性ポリマーを添加して凝集処理し、凝集処理水を直接膜分離装置で膜分離することを特徴とする。 The water treatment method of the present invention is a water treatment method in which an inorganic flocculant is added to the water to be treated, and then the membrane is separated by a membrane separation apparatus. It is characterized in that 100,000 to 8 million water-soluble cationic polymers are added and subjected to agglomeration treatment, and the agglomerated water is directly subjected to membrane separation with a membrane separator.
　本発明の水処理装置は、被処理水に無機凝集剤を添加して凝集処理する第１の凝集処理手段と、該第１の凝集処理手段の凝集処理水に質量平均分子量１０万～８００万の水溶性のカチオン性ポリマーを添加して凝集処理する第２の凝集処理手段と、該第２の凝集処理手段の凝集処理水を直接膜分離する膜分離装置とを有することを特徴とする。 The water treatment apparatus of the present invention includes a first aggregating treatment means for adding an inorganic flocculant to the water to be treated and aggregating treatment water of the first aggregating treatment means, and a mass average molecular weight of 100,000 to 8 million. And a membrane separation device for directly performing membrane separation of the agglomerated water of the second agglomeration treatment means.
［メカニズム］
　本発明によれば、被処理水に最初に無機凝集剤を添加して被処理水中の有機物やＳＳと無機凝集剤とを反応させた後に、カチオン性ポリマーを添加するため、分散する無機凝集剤コロイドや微細フロックとカチオン性ポリマーとを効率的に反応させることができ、カチオン性ポリマー添加後直接膜分離装置で膜分離しても膜分離装置を汚染することなく、また、凝集剤使用量の低減も可能となる。 [mechanism]
According to the present invention, an inorganic flocculant is first added to the water to be treated to react the organic matter or SS in the water to be treated with the inorganic flocculant, and then the cationic polymer is added. Colloids and fine flocs can be reacted efficiently with cationic polymers. Even if the membrane is separated directly with a membrane separator after the addition of the cationic polymer, the membrane separator is not contaminated. Reduction is also possible.
　仮にカチオン性ポリマーを無機凝集剤の前に添加した場合、カチオン性ポリマーが原水中のＳＳや有機物などのアニオン成分と反応して消費される。そのため、無機凝集剤の後にカチオン性ポリマーを添加する場合と比べて、分散した無機凝集剤コロイドと反応するために必要なカチオン性ポリマーの量が増加する。カチオン性ポリマー添加量／無機凝集剤添加量の割合が一定以上になった場合、凝集フロックが分離膜に吸着しやすく膜を汚染しやすくなる。よって、本発明においては、無機凝集剤の添加後にカチオン性ポリマーを添加する。 If a cationic polymer is added before the inorganic flocculant, the cationic polymer reacts with anion components such as SS and organic matter in the raw water and is consumed. This increases the amount of cationic polymer required to react with the dispersed inorganic flocculant colloid as compared to adding the cationic polymer after the inorganic flocculant. When the ratio of the addition amount of the cationic polymer / the addition amount of the inorganic flocculant becomes a certain value or more, the aggregated floc is easily adsorbed on the separation membrane and easily contaminates the membrane. Therefore, in the present invention, the cationic polymer is added after the inorganic flocculant is added.
　本発明で用いるカチオン性ポリマーは、その質量平均分子量が１０万以上と比較的大きいため、後述の実施例に示されるように、凝集フロックが膜閉塞を引き起こし難い。本発明で用いるカチオン性ポリマーは、質量平均分子量８００万以下でかつ水溶性であるため凝集フロックが膜モジュール内に堆積し難い。このため膜分離装置内の汚染を防止して、長期に亘り安定に処理を継続することができる。 Since the cationic polymer used in the present invention has a relatively large mass average molecular weight of 100,000 or more, the aggregated floc is unlikely to cause membrane clogging, as shown in Examples described later. Since the cationic polymer used in the present invention has a mass average molecular weight of 8 million or less and is water-soluble, aggregated flocs are difficult to deposit in the membrane module. For this reason, it is possible to prevent contamination in the membrane separation apparatus and continue the treatment stably over a long period of time.
　本発明では、無機凝集剤とカチオン性ポリマーとの併用で無機凝集剤の添加量を低減することができ、その際にカチオン性ポリマーを無機凝集剤よりも後に添加するため、カチオン性ポリマーの必要添加量を低減することができ、結果として全体の凝集剤使用量を低減することができる。 In the present invention, the amount of the inorganic flocculant added can be reduced by the combined use of the inorganic flocculant and the cationic polymer. At that time, the cationic polymer is added after the inorganic flocculant. The amount added can be reduced, and as a result, the total amount of flocculant used can be reduced.
［被処理水］
　本発明で処理する被処理水としては特に制限はないが、本発明は、無機凝集剤のみでは十分な凝集処理効果を得ることが困難な、リン、生物代謝物、キレート作用を有する有機酸、或いは無機炭素を含む、工業用水、市水、井水、工業排水、排水の生物処理水の処理に有効である。 [Treatment water]
The water to be treated to be treated in the present invention is not particularly limited, but the present invention provides phosphorus, a biological metabolite, an organic acid having a chelating action, which is difficult to obtain a sufficient flocculating effect only with an inorganic flocculant, Alternatively, it is effective for the treatment of biological water such as industrial water, city water, well water, industrial wastewater, and wastewater containing inorganic carbon.
　キレート作用を有する有機酸としては、クエン酸、蟻酸、コハク酸、酢酸及び酪酸などが例示できる。これらの有機酸は例えば半導体製造工程中のメッキ工程などに用いられ、該排水を処理する際に無機凝集剤の錯イオン形成剤あるいは分散剤として作用する。このような有機酸を含む排水の凝集は、凝集ｐＨが高いほど有機酸の錯イオン形成能が高まるため、凝集状態が悪化する。凝集ｐＨが高くなる場合とは、例えば、ＣｕやＭｎ等の重金属処理を目的に凝集を行う場合、或いは、原水中のＴＯＣ除去における最適凝集ｐＨが６以上である場合、無機凝集剤にポリ塩化アルミニウムを用いる場合である。 Examples of organic acids having a chelating action include citric acid, formic acid, succinic acid, acetic acid and butyric acid. These organic acids are used, for example, in a plating process in a semiconductor manufacturing process, and act as a complex ion forming agent or a dispersing agent for an inorganic flocculant when the waste water is treated. In such agglomeration of wastewater containing an organic acid, the higher the aggregation pH, the higher the complex ion forming ability of the organic acid, and the agglomerated state deteriorates. The case where the agglomeration pH becomes high is, for example, when the agglomeration is performed for the purpose of treating heavy metals such as Cu and Mn, or when the optimum agglomeration pH in the TOC removal in the raw water is 6 or more, the inorganic flocculant is polychlorinated. This is the case where aluminum is used.
［無機凝集剤による凝集処理］
　被処理水に添加する無機凝集剤としては、幅広いｐＨ範囲でフロックを形成することができる鉄系又はアルミニウム系の無機凝集剤を使用することが好ましい。鉄系無機凝集剤としては、塩化第二鉄、硫酸第二鉄、ポリ塩化第二鉄、ポリ硫酸第二鉄などが挙げられる。アルミニウム系無機凝集剤としては、ポリ塩化アルミニウムや硫酸アルミニウムが挙げられる。特に凝集効果とコストの面で鉄系無機凝集剤である塩化第二鉄が好ましい。これらの無機凝集剤は、１種を単独で用いてもよく、２種以上を混合して用いてもよい。 [Aggregation treatment with inorganic flocculant]
As the inorganic flocculant added to the water to be treated, it is preferable to use an iron-based or aluminum-based inorganic flocculant capable of forming flocs in a wide pH range. Examples of the iron-based inorganic flocculant include ferric chloride, ferric sulfate, polyferric chloride, and polyferric sulfate. Examples of the aluminum-based inorganic flocculant include polyaluminum chloride and aluminum sulfate. In particular, ferric chloride, which is an iron-based inorganic flocculant, is preferable from the viewpoints of the aggregation effect and cost. These inorganic flocculants may be used individually by 1 type, and 2 or more types may be mixed and used for them.
　被処理水への無機凝集剤の添加量は、被処理水の水質や、用いる無機凝集剤の種類、要求される処理水水質等によっても異なるが、有効成分量として２～１００ｍｇ／Ｌの範囲とすることが好ましい。 The amount of the inorganic flocculant added to the water to be treated varies depending on the quality of the water to be treated, the type of inorganic flocculant used, the quality of the water to be treated, etc., but the amount of active ingredient is in the range of 2 to 100 mg / L. It is preferable that
　無機凝集剤はその種類に応じて、好適凝集処理ｐＨ範囲が存在し、塩化第二鉄等の鉄系無機凝集剤ではｐＨ５～６程度が好ましく、アルミニウム系無機凝集剤ではｐＨ６～７程度が好ましい。従って、必要に応じて酸又はアルカリを添加して好適ｐＨ範囲にｐＨ調整することが好ましい。 The inorganic flocculant has a suitable flocculation treatment pH range depending on the type thereof. For iron-based inorganic flocculants such as ferric chloride, the pH is preferably about 5 to 6, and for aluminum-based inorganic flocculants, the pH is preferably about 6 to 7. . Therefore, it is preferable to adjust the pH to a suitable pH range by adding an acid or an alkali as necessary.
　被処理水に無機凝集剤を添加した後は被処理水中の有機物やＳＳと無機凝集剤とを十分に反応させるために２～１０分程度急速攪拌することが好ましい。 After adding the inorganic flocculant to the water to be treated, rapid stirring is preferably performed for about 2 to 10 minutes in order to sufficiently react the organic matter or SS in the water to be treated with the inorganic flocculant.
　本発明において、急速攪拌とは回転数として１００～２００ｒｐｍ程度をさし、緩速攪拌とは回転数として２０～１００ｒｐｍ程度をさす。 In the present invention, rapid stirring refers to about 100 to 200 rpm as the rotational speed, and slow stirring refers to about 20 to 100 rpm as the rotational speed.
［カチオン性ポリマーによる凝集処理］
　本発明で用いるカチオン性ポリマーは、質量平均分子量１０万～８００万の水溶性のものである。 [Agglomeration treatment with cationic polymer]
The cationic polymer used in the present invention is a water-soluble one having a mass average molecular weight of 100,000 to 8 million.
　「水溶性」とは、水に対する溶解度が１ｇ以上／水１００ｇ（２０℃）であることをさす。
　「カチオン性ポリマー」とは、コロイド当量が正の値を示すものであり、例えばコロイド当量は、１．０～６．０ｍｅｑ／ｇであることが好ましい。コロイド当量は１／４００ＮのＰＶＳＫ（ポリビニル硫酸カリウム）で滴定を行い、流動電位法により測定される。 “Water-soluble” means that the solubility in water is 1 g or more / 100 g of water (20 ° C.).
The “cationic polymer” is one having a positive colloidal equivalent. For example, the colloidal equivalent is preferably 1.0 to 6.0 meq / g. The colloidal equivalent is measured by the streaming potential method after titration with 1 / 400N PVSK (polyvinyl potassium sulfate).
　カチオン性ポリマーの質量平均分子量とは、クロマトグラフィー法（ＧＰＣ法）により測定された質量平均分子量の値である。 The mass average molecular weight of the cationic polymer is a value of a mass average molecular weight measured by a chromatography method (GPC method).
　カチオン性ポリマーの質量平均分子量が１０万未満では、形成される凝集フロックが微細になるため膜閉塞を引き起こし易い。カチオン性ポリマーの質量平均分子量が８００万を超えると凝集フロックが粗大になりすぎ、膜モジュール内に堆積しやすくなる。このため、本発明で用いるカチオン性ポリマーの質量平均分子量は１０万～８００万、好ましくは２０万～１００万の範囲とする。 If the weight average molecular weight of the cationic polymer is less than 100,000, the aggregated flocs that are formed become fine, and membrane clogging is likely to occur. When the mass average molecular weight of the cationic polymer exceeds 8 million, the aggregated flocs become too coarse and are easily deposited in the membrane module. Therefore, the weight average molecular weight of the cationic polymer used in the present invention is in the range of 100,000 to 8 million, preferably 200,000 to 1 million.
　カチオン性ポリマーとしては、上記の質量平均分子量を有する水溶性のものであればよく、特に制限はないが、カチオン性モノマーとアクリルアミド等のノニオン性モノマーとの共重合物を好適に用いることができる。 The cationic polymer is not particularly limited as long as it is water-soluble having the above-described mass average molecular weight, but a copolymer of a cationic monomer and a nonionic monomer such as acrylamide can be suitably used. .
　カチオン性モノマーとしては、例えばジメチルアミノエチルアクリレートやジメチルアミノエチルメタクリレートの酸塩もしくはその４級アンモニウム塩、ジメチルアミノプロピルアクリアミドやジメチルアミノプロピルメタクリアミドの酸塩もしくはその４級アンモニウム塩を好適に用いることができるが、これらに限定されるものではない。４級アンモニウム塩としては、メチルクロライドやエチルクロライドなどの４級アンモニウム塩を用いることができる。 As the cationic monomer, for example, dimethylaminoethyl acrylate or dimethylaminoethyl methacrylate acid salt or quaternary ammonium salt thereof, dimethylaminopropyl acryamide or dimethylaminopropyl methacrylate acid acid salt or quaternary ammonium salt is preferably used. However, it is not limited to these. As the quaternary ammonium salt, a quaternary ammonium salt such as methyl chloride or ethyl chloride can be used.
　カチオン性ポリマーは１種を単独で用いてもよく、２種以上を混合して用いてもよい。 As the cationic polymer, one kind may be used alone, or two or more kinds may be mixed and used.
　無機凝集剤による凝集処理水（以下、「無機凝集処理水」と称す場合がある。）へのカチオン性ポリマーの添加量は、被処理水或いは無機凝集処理水の水質や用いるカチオン性ポリマーの種類によっても異なるが、有効成分量として０．１～５ｍｇ／Ｌの範囲とすることが好ましい。 The amount of the cationic polymer added to the agglomerated treated water with inorganic coagulant (hereinafter sometimes referred to as “inorganic agglomerated treated water”) depends on the quality of the water to be treated or the inorganic agglomerated treated water and the type of the cationic polymer used. The amount of active ingredient is preferably in the range of 0.1 to 5 mg / L, although it varies depending on the type of active ingredient.
　無機凝集処理水にカチオン性ポリマーを添加した後は、カチオン性ポリマーとの反応時間を確保するために２～１０分程度の急速攪拌と、その後２～１０分程度の緩速攪拌を行うことが好ましい。 After the cationic polymer is added to the inorganic agglomerated water, rapid stirring for about 2 to 10 minutes and then slow stirring for about 2 to 10 minutes may be performed in order to ensure the reaction time with the cationic polymer. preferable.
［膜分離装置による膜分離］
　無機凝集処理水にカチオン性ポリマーを添加して凝集処理して得られた凝集処理水（以下、「カチオン凝集処理水」と称す場合がある。）は、直接膜分離装置で膜分離する。 [Membrane separation by membrane separator]
The agglomerated water obtained by adding a cationic polymer to the inorganic agglomerated water (hereinafter sometimes referred to as “cation agglomerated water”) is directly subjected to membrane separation by a membrane separation device.
　「直接膜分離する」とは、カチオン凝集処理水に更なる凝集剤の添加や、沈殿槽等による固液分離等を行わずに、そのまま膜分離装置に給水することをさす。 “Direct membrane separation” means that water is directly supplied to the membrane separation apparatus without adding a flocculant to the cation flocculation treated water or performing solid-liquid separation using a precipitation tank or the like.
　本発明で用いる膜分離装置については、その膜素材、膜形式や構造には特に制限はない。膜分離装置としてはＭＦ膜分離装置又はＵＦ膜分離装置を用いることが好ましい。 The membrane separator used in the present invention is not particularly limited in its membrane material, membrane type and structure. As the membrane separator, an MF membrane separator or a UF membrane separator is preferably used.
　ＵＦ膜、ＭＦ膜の孔径は、０．２μｍ以下、例えば０．１～０．０１μｍ程度が好ましい。 The pore size of the UF membrane and MF membrane is preferably 0.2 μm or less, for example, about 0.1 to 0.01 μm.
　膜分離装置による膜分離方式にも特に制限はない。後述の実施例ではデッドエンド通水方式で行っているが、クロスフロー通水方式であってもよい。 There is no particular limitation on the membrane separation method using the membrane separator. In the embodiment described later, the dead end water flow method is used, but a cross flow water flow method may be used.
［高度処理］
　上記の膜分離装置による膜分離で得られる処理水は有機物、ＳＳ等が十分に除去された高水質のものであり、これをそのまま工業用水として使用したり放流することができるが、必要に応じて逆浸透（ＲＯ）膜分離装置でＲＯ膜処理してもよい。この場合において、ＲＯ膜処理に供する水が十分に高水質であるため、ＲＯ膜分離装置の差圧上昇等の問題を引き起こすことなく、安定かつ効率的な処理を行って、高水質の純水を得ることができる。 [Advanced processing]
The treated water obtained by membrane separation by the above membrane separator is of high quality from which organic substances, SS, etc. are sufficiently removed, and can be used as industrial water or discharged as it is, but if necessary Alternatively, RO membrane treatment may be performed by a reverse osmosis (RO) membrane separation apparatus. In this case, since the water used for the RO membrane treatment is sufficiently high in quality, stable and efficient treatment is performed without causing problems such as an increase in the differential pressure of the RO membrane separator, and high-quality pure water is used. Can be obtained.
［凝集剤添加量の制御］
　無機凝集処理水に対してカチオン性ポリマーを過剰添加した場合、カチオン凝集処理水中の荷電がプラス雰囲気になるため、カチオン性ポリマーの吸着対象物質（原水中ＳＳ、有機物、無機凝集剤コロイド）の除去率を低下させる結果となる。そのため、被処理水の電荷を中和するために必要なカチオン消費量Ａを測定し、添加する凝集剤の総カチオン量を被処理水のカチオン消費量Ａ以下に調整することが好ましい。被処理水のカチオン消費量Ａは流動電位法により、被処理水を用いるカチオン性ポリマーで滴定することにより求めることができる。 [Control of amount of flocculant added]
When the cationic polymer is added excessively to the inorganic agglomerated treated water, the charge in the cationic agglomerated treated water becomes a positive atmosphere. As a result, the rate decreases. Therefore, it is preferable to measure the cation consumption A necessary for neutralizing the charge of the water to be treated and adjust the total cation amount of the flocculant to be added to the cation consumption A or less of the water to be treated. The cation consumption A of the water to be treated can be determined by titration with a cationic polymer using the water to be treated by the streaming potential method.
　本発明では、このようにして被処理水のカチオン消費量Ａを求め、無機凝集剤とカチオン性ポリマーの添加濃度とが下記関係式（Ｉ）を満たすように、無機凝集剤とカチオン性ポリマーの添加量を制御することが好ましい。
　カチオン消費量Ａ×α＝
　　カチオン性ポリマー添加濃度（ｍｇ／Ｌ）＋無機凝集剤添加濃度（ｍｇ／Ｌ）×β　　…（Ｉ） In the present invention, the cation consumption A of the water to be treated is obtained in this way, and the inorganic flocculant and the cationic polymer are added so that the added concentration of the inorganic flocculant and the cationic polymer satisfies the following relational expression (I). It is preferable to control the addition amount.
Cation consumption A × α =
Cationic polymer addition concentration (mg / L) + Inorganic flocculant addition concentration (mg / L) × β (I)
　αは水質変動を加味した安全係数であり、通常、０．６～０．９程度である。
　βは、用いる無機凝集剤のカチオン量をカチオン性ポリマーのカチオン量に換算する係数であり、流動電流計を用いた滴定により求められる。 α is a safety factor taking into account fluctuations in water quality, and is usually about 0.6 to 0.9.
β is a coefficient for converting the cation amount of the inorganic flocculant used to the cation amount of the cationic polymer, and is obtained by titration using a flow ammeter.
　上記のカチオン性ポリマーと無機凝集剤の添加量の制御は、予め求めた被処理水のカチオン消費量Ａと用いる無機凝集剤の換算係数βと、予め設定された安全係数αが入力される制御手段により自動制御で行うことができる。 Control of the addition amount of the cationic polymer and the inorganic flocculant is performed by inputting the cation consumption A of the water to be treated obtained in advance, the conversion coefficient β of the inorganic flocculant to be used, and the preset safety coefficient α. It can be performed automatically by means.
　以下に実施例を挙げて本発明をより具体的に説明する。 Hereinafter, the present invention will be described more specifically with reference to examples.
　以下の実施例及び比較例で用いた無機凝集剤及びカチオン性ポリマーは以下の通りである。
　　無機凝集剤：塩化第二鉄
　　カチオン性ポリマー：質量平均分子量５万、１０万、２０万、７０万、１００万、８００万又は１０００万のジメチルアミノエチルアクリレート・メチルクロライド四級塩／アクリルアミド共重合体（コロイド当量２．５～３．０ｍｅｑ／ｇ） The inorganic flocculants and cationic polymers used in the following examples and comparative examples are as follows.
Inorganic flocculant: ferric chloride Cationic polymer: dimethylaminoethyl acrylate / methyl chloride quaternary salt / acrylamide copolymer having a mass average molecular weight of 50,000, 100,000, 200,000, 700,000, 1 million, 8 million or 10 million Combined (colloid equivalent 2.5-3.0 meq / g)
　試験装置としては、図１（ａ），（ｂ）に示す外圧式ミニモジュール試験装置（外圧式中空糸ＵＦ膜、孔径：０．０２μｍ、膜長さ：７．５ｃｍ、膜面積：１０．６ｃｍ２、膜素材ポリフッ化ビニリデン）を用いた。 As the test apparatus, an external pressure type mini-module test apparatus shown in FIGS. 1A and 1B (external pressure type hollow fiber UF membrane, pore diameter: 0.02 μm, membrane length: 7.5 cm, membrane area: 10.6 cm) 2 , film material polyvinylidene fluoride) was used.
　図１（ａ）中、１は中空糸膜、２はポッティング剤、３は原水導入口、４は排水口である。５はモジュールハウジングであり、内部に中空糸膜１が装填されている。原水は導入口３からハウジング５内に導入され、中空糸膜１を透過した透過水が中空糸膜１の膜内からハウジング５外へ取り出される。 In FIG. 1 (a), 1 is a hollow fiber membrane, 2 is a potting agent, 3 is a raw water inlet, and 4 is a drain. Reference numeral 5 denotes a module housing in which the hollow fiber membrane 1 is loaded. The raw water is introduced into the housing 5 from the inlet 3, and the permeated water that has permeated through the hollow fiber membrane 1 is taken out from the inside of the hollow fiber membrane 1 to the outside of the housing 5.
　外圧式中空糸ミニモジュール１０に図１（ｂ）の通り配管を接続して外圧式ミニモジュール試験装置とした。この試験装置では、原水の処理時は、バルブＶ１，Ｖ２，Ｖ３を閉として、ポンプＰを作動させて、給水タンク６から配管１１を経て原水を外圧式ミニモジュール１０に導入し、透過水を配管１３を経て処理水タンク７に送給するデッドエンド通水方式で膜分離を行う。膜の逆洗浄を行う際は、ポンプＰを停止し、バルブＶ１を閉、Ｖ２，Ｖ３を開として、配管１３Ａより空気を配管１３に送気し、配管１３内の水を中空糸膜１の内側（２次側）から外側（１次側）へ透過させる。排水時は、ポンプＰを停止した状態で、バルブＶ１，Ｖ２を開、バルブＶ３を閉として、配管１１Ａから空気を配管１１に送気し、配管１２よりモジュール１０内の水を排出させる。配管１１Ａ，１３Ａからの空気は０．１５ＭＰａで送気した。水張り時は、バルブＶ２を開、バルブＶ１，Ｖ３を閉として、ポンプＰを作動させて給水タンク６内の水をモジュール１０内に導入する。ＰＩは圧力計である。 Pipes were connected to the external pressure hollow fiber mini-module 10 as shown in FIG. In this test apparatus, when the raw water is treated, the valves V 1 , V 2 and V 3 are closed, the pump P is operated, and the raw water is introduced from the water supply tank 6 through the pipe 11 into the external pressure mini-module 10. Membrane separation is performed by a dead-end water passing method in which permeated water is supplied to the treated water tank 7 through the pipe 13. When performing backwashing of the membrane, the pump P is stopped, the valve V 1 is closed, the V 2, V 3 is opened and air was supplied to the pipe 13 from the pipe 13A, the hollow fiber water in the pipe 13 Permeation from the inner side (secondary side) of the membrane 1 to the outer side (primary side). During wastewater, while stopping the pump P, and valve V 1, V 2 opens, the valve V 3 is closed, the air air into the pipe 11 from the pipe 11A, the discharge of water of the pipe 12 from the module 10 Let Air from the pipes 11A and 13A was supplied at 0.15 MPa. At the time of water filling, the valve V 2 is opened, the valves V 1 and V 3 are closed, the pump P is operated, and the water in the water supply tank 6 is introduced into the module 10. PI is a pressure gauge.
［実施例１～５、比較例１～２］
　液晶工場排水の生物処理水（ＳＳ濃度：４０ｍｇ／Ｌ、ＴＯＣ：２～２．５ｍｇ／Ｌ）を１５０ｒｐｍで急速攪拌しながら無機凝集剤（塩化第二鉄）を３８％水溶液として１００ｍｇ／Ｌを添加し、次いでｐＨ調整剤（水酸化ナトリウム）を用いてｐＨ５．５に調整した。更に５分間急速攪拌した後、引き続き１５０ｒｐｍで急速攪拌しながら、表１に示す通り、質量平均分子量の異なるカチオン性ポリマー０．６ｍｇ／Ｌをそれぞれ添加して５分間反応させた後に、５０ｒｐｍでさらに５分間緩速攪拌して凝集処理を行った。 [Examples 1 to 5, Comparative Examples 1 and 2]
Biologically treated water (SS concentration: 40 mg / L, TOC: 2 to 2.5 mg / L) of liquid crystal factory wastewater is rapidly stirred at 150 rpm while inorganic flocculant (ferric chloride) is used as a 38% aqueous solution to give 100 mg / L. Then, the pH was adjusted to 5.5 using a pH adjuster (sodium hydroxide). After further rapidly stirring for 5 minutes and then continuously stirring at 150 rpm, as shown in Table 1, 0.6 mg / L of a cationic polymer having a different mass average molecular weight was added and reacted for 5 minutes. Aggregation was carried out with gentle stirring for 5 minutes.
　得られた凝集処理水を、図１（ａ），（ｂ）に示す外圧式ミニモジュール試験装置に４８時間通水した。通水中、フラックス４ｍ３／ｍ２／ｄの濾過２８分おきに逆洗浄（３０秒）、次いで排水（３０秒）、その後水張り（３０秒）を行い、配管１１に設けた圧力計Ｐｌで測定される膜間差圧の上昇速度を調べた。 The obtained agglomerated water was passed through an external pressure mini-module test apparatus shown in FIGS. 1 (a) and 1 (b) for 48 hours. Measured with a pressure gauge Pl provided on the pipe 11 after passing through water and backwashing every 30 minutes with a flux of 4 m 3 / m 2 / d (30 seconds), then draining (30 seconds), and then watering (30 seconds). The rate of increase in transmembrane pressure was investigated.
　また、給水（膜分離処理に供した凝集処理水）のＳＳ濃度と、４８時間の通水で得られた排水中のＳＳ量を測定し、モジュール内のＳＳ残留率を以下の式で算出した。 In addition, the SS concentration of the feed water (flocculated treated water subjected to membrane separation treatment) and the amount of SS in the wastewater obtained by passing water for 48 hours were measured, and the SS residual ratio in the module was calculated by the following formula. .
Figure JPOXMLDOC01-appb-M000001
Figure JPOXMLDOC01-appb-M000001
　給水ＳＳ濃度および排水中ＳＳ量は、これらの水を、直径４７ｍｍ、孔径１μｍのガラス濾紙で濾過した際に得られる濾取物の乾燥重量として測定した。結果を表１に示す。 The feed water SS concentration and the amount of SS in the wastewater were measured as the dry weight of the filtered material obtained when these waters were filtered through glass filter paper having a diameter of 47 mm and a pore diameter of 1 μm. The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表１より次のことが分かる。
　低分子量の質量平均分子量を用いると、フロックが微細になるため膜閉塞を生じやすく、差圧上昇速度が大きくなる傾向を示した（比較例１）。カチオン性ポリマーの分子量が大きくなると、フロックが粗大になるためモジュール内に堆積しやすく、ＳＳ残留率が増加した（比較例２）。これらの結果から、膜汚染性の観点から、カチオン性ポリマーの適正質量平均分子量は１０万～８００万であり、望ましくは２０万～１００万であることが分かる。 Table 1 shows the following.
When the mass average molecular weight having a low molecular weight was used, the flocs became fine, so that the membrane was likely to be clogged and the rate of increase in the differential pressure tended to increase (Comparative Example 1). When the molecular weight of the cationic polymer is increased, flocs are coarsened, so that they are easily deposited in the module, and the SS residual ratio is increased (Comparative Example 2). From these results, it is understood that the proper mass average molecular weight of the cationic polymer is 100,000 to 8 million, and desirably 200,000 to 1 million from the viewpoint of membrane contamination.
［実験例Ｉ］
　以下の無機凝集剤とカチオン性ポリマーを用いて、無機凝集剤とカチオン性ポリマーの添加順序による効果を調べる実験を行った。
　　無機凝集剤：塩化第二鉄
　　カチオン性ポリマー：質量平均分子量２０万のポリジアリルジメチルアンモニウムクロライド（コロイド当量５．９ｍｅｑ／ｇ、固有粘度０．７５ｄｇ／Ｌ）
　　試験水：国内工業用水にリン酸（リン酸は無機凝集剤を分散させる目的で添加した。）を６ｍｇ／Ｌ　ａｓＰになるように添加したモデル水を用いた。 [Experimental Example I]
Using the following inorganic flocculant and cationic polymer, an experiment was conducted to examine the effect of the addition order of the inorganic flocculant and the cationic polymer.
Inorganic flocculant: Ferric chloride Cationic polymer: Polydiallyldimethylammonium chloride having a mass average molecular weight of 200,000 (colloid equivalent 5.9 meq / g, intrinsic viscosity 0.75 dg / L)
Test water: Model water to which phosphoric acid (phosphoric acid was added for the purpose of dispersing the inorganic flocculant) was added to domestic industrial water so as to be 6 mg / L asP was used.
　試験方法は以下の通りである。 The test method is as follows.
　試験水に無機凝集剤（塩化第二鉄）を３８％水溶液として７５ｍｇ／Ｌおよびカチオン性ポリマー０．６ｍｇ／Ｌ（純分として）を添加し、ｐＨ調整剤（水酸化ナトリウム）を用いてｐＨ５．５に調整して凝集処理し、得られた凝集処理水を、Ｎｏ．５Ａろ紙でろ過した後、ろ液をφ２５ｍｍ、孔径０．４５μｍの酢酸セルロースメンブレンフィルターを用いて－５００ｍｍＨｇで減圧濾過した。このとき、初めの１５０ｍＬをろ過するのに要した時間をＴ１（秒）、次の１５０ｍＬをろ過するのに要した時間をＴ２（秒）とし、ＭＦＦ＝Ｔ２／Ｔ１で処理水の評価を行った。
　ＭＦＦは小さい値であるほど、良好な水質であることを意味する。 75 mg / L of inorganic flocculant (ferric chloride) as a 38% aqueous solution and 0.6 mg / L of cationic polymer (as pure component) are added to the test water, and the pH is adjusted to 5 using a pH adjuster (sodium hydroxide). No. 5 was subjected to flocculation treatment, and the obtained flocculation water was designated After filtration through 5A filter paper, the filtrate was filtered under reduced pressure at −500 mmHg using a cellulose acetate membrane filter having a diameter of 25 mm and a pore diameter of 0.45 μm. At this time, the time required to filter the first 150 mL is T1 (seconds), the time required to filter the next 150 mL is T2 (seconds), and the treated water is evaluated at MFF = T2 / T1. It was.
A smaller value of MFF means better water quality.
　無機凝集剤及びカチオン性ポリマーによる凝集処理手順は、各例毎に以下の通りとした。
　実験例Ｉ－１（無機凝集剤添加後カチオン性ポリマー添加）：試験水を１５０ｒｐｍで急速撹拌しながら無機凝集剤を添加し、次いでｐＨ調整剤を用いてｐＨ５．５に調整し、更に５分間急速撹拌し、急速撹拌しながらカチオン性ポリマーを添加して５分間反応させ、その後、５０ｒｐｍで更に５分間緩速撹拌して凝集処理した。
　実験例Ｉ－２（カチオン性ポリマー添加後無機凝集剤添加）：試験水を１５０ｒｐｍで急速撹拌しながらカチオン性ポリマーを添加し、次いで無機凝集剤を添加した後にｐＨ調整剤を用いてｐＨ５．５に調整し、更に５分間急速撹拌した。その後、５０ｒｐｍで更に５分間緩速撹拌して凝集処理した。
　実験例Ｉ－３（カチオン性ポリマー及び無機凝集剤同時添加）：試験水を１５０ｒｐｍで急速撹拌しながら無機凝集剤とカチオン性ポリマーを同時に添加し、次いでｐＨ調整剤を用いてｐＨ５．５に調整し、５０ｒｐｍで更に５分間緩速撹拌して凝集処理した。 The aggregation treatment procedure using the inorganic flocculant and the cationic polymer was as follows for each example.
Experimental Example I-1 (Addition of cationic flocculant after addition of inorganic flocculant): Inorganic flocculant was added while rapidly stirring the test water at 150 rpm, then adjusted to pH 5.5 using a pH adjuster, and further for 5 minutes While stirring rapidly, the cationic polymer was added with rapid stirring and reacted for 5 minutes, and then the mixture was gently stirred at 50 rpm for another 5 minutes for aggregation treatment.
Experimental Example I-2 (Addition of inorganic flocculant after addition of cationic polymer): The cationic polymer was added while rapidly stirring the test water at 150 rpm, and then the inorganic flocculant was added and then pH 5.5 using a pH adjuster. And stirred rapidly for another 5 minutes. Thereafter, the mixture was agitated at 50 rpm for a further 5 minutes to agglomerate.
Experimental Example I-3 (simultaneous addition of cationic polymer and inorganic flocculant): Inorganic flocculant and cationic polymer were simultaneously added while rapidly stirring the test water at 150 rpm, and then adjusted to pH 5.5 using a pH adjuster Then, the mixture was agitated at 50 rpm for a further 5 minutes to agglomerate.
　結果を図２に示す。
　図２より次のことが明らかである。
　実験例Ｉ－２，３は、いずれも無機凝集剤添加後カチオン性ポリマーを添加した実験例Ｉ－１よりもＭＦＦが大きく、凝集不良であった。これは、原水中のアニオン成分とカチオン性ポリマーが反応し、分散する無機凝集剤コロイドと反応しきれなかったためである。本結果より、分散する無機凝集剤を捕捉する目的でカチオン性ポリマーを用いる場合、無機凝集剤の後にカチオン性ポリマーを添加する方が、カチオン性ポリマーを効率よく使用できるため、少量の添加量で充分な凝集効果が得られることが分かる。 The results are shown in FIG.
The following is clear from FIG.
In Experimental Examples I-2 and 3, both had MFF larger than Experimental Example I-1 in which the cationic polymer was added after the addition of the inorganic flocculant, and the aggregation was poor. This is because the anionic component in the raw water and the cationic polymer reacted and could not react with the dispersed inorganic flocculant colloid. From this result, when a cationic polymer is used for the purpose of capturing the dispersed inorganic flocculant, the cationic polymer can be used more efficiently after adding the cationic polymer after the inorganic flocculant. It can be seen that a sufficient aggregation effect is obtained.
［実験例II］
　実験例Ｉで用いた無機凝集剤とカチオン性ポリマーと同一の無機凝集剤とカチオン性ポリマーを用い、キレート効果を有する有機酸を含む排水に対するカチオン性ポリマーの効果を調べる実験を行った。
　試験水としては、国内半導体工場のメッキ工程排水（有機酸を含む溶存有機物濃度１０～２０ｍｇ／Ｌ，銅濃度６ｍｇ／Ｌ）を用いた。 [Experimental example II]
Using the same inorganic flocculant and cationic polymer as those used in Experimental Example I, an experiment was conducted to examine the effect of the cationic polymer on wastewater containing an organic acid having a chelating effect.
As test water, the wastewater from the plating process of a domestic semiconductor factory (dissolved organic matter concentration including organic acid 10 to 20 mg / L, copper concentration 6 mg / L) was used.
　試験方法は、以下の通りである。 The test method is as follows.
　試験水中の銅を除去する目的で凝集処理を実施した。試験水を１５０ｒｐｍで急速攪拌しながら無機凝集剤（塩化第二鉄）を３８％水溶液として５００ｍｇ／Ｌを添加し、次いでｐＨ調整剤（水酸化ナトリウム）を用いてｐＨ９に調整した。更に５分間急速攪拌した後、急速撹拌しながらカチオン性ポリマー０～５ｍｇ／Ｌ（純分として表２に示す添加量）を添加して５分間反応させた。その後、５０ｒｐｍでさらに５分間緩速攪拌してフロックを成長させた。得られた凝集処理水を、Ｎｏ．５Ａろ紙でろ過した後、ろ液中の銅イオン濃度を測定した。
　銅イオン濃度が低いほど、凝集処理が効果的に実施され、凝集状態が良好であることを意味する。
　結果を表２に示す。 Aggregation treatment was performed for the purpose of removing copper in the test water. 500 mg / L of an inorganic flocculant (ferric chloride) as a 38% aqueous solution was added while rapidly stirring the test water at 150 rpm, and then adjusted to pH 9 using a pH adjuster (sodium hydroxide). After further rapid stirring for 5 minutes, 0-5 mg / L of a cationic polymer (addition amount shown in Table 2 as a pure content) was added with rapid stirring and reacted for 5 minutes. Thereafter, the flocs were grown by gently stirring at 50 rpm for another 5 minutes. The obtained agglomerated treated water was No. After filtering with 5A filter paper, the copper ion concentration in the filtrate was measured.
It means that the lower the copper ion concentration, the more effectively the aggregation treatment is performed and the better the aggregation state.
The results are shown in Table 2.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表２より、カチオン性ポリマーの添加量の増加に伴い、ろ液の銅イオン濃度が低下しており、凝集状態が改善されたことが分かる。 From Table 2, it can be seen that the copper ion concentration in the filtrate decreased with the increase in the amount of the cationic polymer added, and the aggregation state was improved.
　本発明を特定の態様を用いて詳細に説明したが、本発明の意図と範囲を離れることなく様々な変更が可能であることは当業者に明らかである。
　本出願は、２０１８年４月２５日付で出願された日本特許出願２０１８－０８４２６４に基づいており、その全体が引用により援用される。 Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.
This application is based on Japanese Patent Application No. 2018-084264 filed on Apr. 25, 2018, which is incorporated by reference in its entirety.
　１　中空糸膜
　２　ポッティング剤
　３　原水導入口
　４　排水口
　５　モジュールハウジング
　６　給水タンク
　７　処理水タンク
　１０　外圧式中空糸ミニモジュール DESCRIPTION OF SYMBOLS 1 Hollow fiber membrane 2 Potting agent 3 Raw water inlet 4 Drain outlet 5 Module housing 6 Water supply tank 7 Treated water tank 10 External pressure type hollow fiber mini module

Claims (10)

  1. 　被処理水に無機凝集剤を添加して凝集処理した後に膜分離装置で膜分離する水処理方法において、被処理水に無機凝集剤を添加した後、質量平均分子量１０万～８００万の水溶性のカチオン性ポリマーを添加して凝集処理し、凝集処理水を直接膜分離装置で膜分離することを特徴とする水処理方法。 In a water treatment method in which an inorganic flocculant is added to water to be treated and then subjected to a membrane separation with a membrane separation apparatus, an inorganic flocculant is added to the water to be treated, and then water-soluble having a mass average molecular weight of 100,000 to 8 million. A water treatment method, comprising adding a cationic polymer to agglomerate, and subjecting the agglomerated water to membrane separation directly with a membrane separator.
  2. 　前記被処理水がリン、生物代謝物、キレート作用を有する有機酸、及び無機炭素のいずれかを含む、工業用水、市水、井水、工業排水、或いは排水の生物処理水である請求項１に記載の水処理方法。 2. The treated water is industrial water, city water, well water, industrial wastewater, or biologically treated water containing any one of phosphorus, biological metabolites, chelating organic acids, and inorganic carbon. The water treatment method as described in any one of.
  3. 　前記膜分離装置が、精密濾過膜分離装置又は限外濾過膜分離装置である請求項１又は２に記載の水処理方法。 The water treatment method according to claim 1 or 2, wherein the membrane separation device is a microfiltration membrane separation device or an ultrafiltration membrane separation device.
  4. 　前記膜分離装置で得られた処理水を、さらに逆浸透膜処理する請求項１～３のいずれかに記載の水処理方法。 The water treatment method according to any one of claims 1 to 3, wherein the treated water obtained by the membrane separation device is further subjected to a reverse osmosis membrane treatment.
  5. 　流動電位法により前記被処理水を前記カチオン性ポリマーで滴定することで、該被処理水の電荷を中和するのに必要な該カチオン性ポリマーの必要量をカチオン消費量Ａとして求め、該カチオン消費量Ａと前記無機凝集剤及び該カチオン性ポリマーの添加濃度とが下記関係式（Ｉ）を満たすように、該カチオン性ポリマーの添加量と該無機凝集剤の添加量を制御する請求項１～４のいずれかに記載の水処理方法。
    　カチオン消費量Ａ×α＝
    　　カチオン性ポリマー添加濃度（ｍｇ／Ｌ）＋無機凝集剤添加濃度（ｍｇ／Ｌ）×β　　…（Ｉ）
    　　α：水質変動を加味した安全係数
    　　β：無機凝集剤のカチオン量をカチオン性ポリマーのカチオン量に換算する係数     By titrating the water to be treated with the cationic polymer by the streaming potential method, the necessary amount of the cationic polymer necessary for neutralizing the charge of the water to be treated is obtained as the cation consumption A, and the cation 2. The addition amount of the cationic polymer and the addition amount of the inorganic flocculant are controlled so that the consumption A and the addition concentration of the inorganic flocculant and the cationic polymer satisfy the following relational expression (I). 5. The water treatment method according to any one of 4 to 4.
    Cation consumption A × α =
    Cationic polymer addition concentration (mg / L) + Inorganic flocculant addition concentration (mg / L) × β (I)
    α: Safety factor taking into account fluctuations in water quality β: Factor for converting the cation amount of the inorganic flocculant into the cation amount of the cationic polymer
  6. 　被処理水に無機凝集剤を添加して凝集処理する第１の凝集処理手段と、該第１の凝集処理手段の凝集処理水に質量平均分子量１０万～８００万の水溶性のカチオン性ポリマーを添加して凝集処理する第２の凝集処理手段と、該第２の凝集処理手段の凝集処理水を直接膜分離する膜分離装置とを有することを特徴とする水処理装置。 A first flocculation treatment means for adding an inorganic flocculant to the water to be treated, and a water-soluble cationic polymer having a mass average molecular weight of 100,000 to 8 million in the flocculation treatment water of the first flocculation treatment means; A water treatment apparatus comprising: a second agglomeration treatment means for adding and agglomerating treatment; and a membrane separation device for directly performing membrane separation on the agglomeration treated water of the second agglomeration treatment means.
  7. 　前記被処理水がリン、生物代謝物、キレート作用を有する有機酸、及び無機炭素のいずれかを含む、工業用水、市水、井水、工業排水、或いは排水の生物及び無機炭素のいずれかを含む、工業用水、市水、井水、工業排水、或いは排水の生物処理水である請求項６に記載の水処理装置。 The treated water contains any one of industrial water, city water, well water, industrial wastewater, or wastewater organisms and inorganic carbon, including any of phosphorus, biological metabolites, chelating organic acids, and inorganic carbon The water treatment apparatus according to claim 6, wherein the water treatment apparatus comprises industrial water, city water, well water, industrial wastewater, or biological wastewater.
  8. 　前記膜分離装置が、精密濾過膜分離装置又は限外濾過膜分離装置である請求項６又は７に記載の水処理装置。 The water treatment device according to claim 6 or 7, wherein the membrane separation device is a microfiltration membrane separation device or an ultrafiltration membrane separation device.
  9. 　前記膜分離装置で得られた処理水を処理する逆浸透膜分離装置を更に有する請求項６～８のいずれかに記載の水処理装置。 The water treatment device according to any one of claims 6 to 8, further comprising a reverse osmosis membrane separation device for treating treated water obtained by the membrane separation device.
  10. 　流動電位法により前記被処理水を前記カチオン性ポリマーで滴定することで、該被処理水の電荷を中和するのに必要な該カチオン性ポリマーの必要量をカチオン消費量Ａとして求め、前記無機凝集剤及び該カチオン性ポリマーの添加濃度とが、下記関係式（Ｉ）を満たすように、該カチオン性ポリマーの添加量と該無機凝集剤の添加量を制御する手段を更に有する請求項６～９のいずれかに記載の水処理装置。
    　カチオン消費量Ａ×α＝
    　　カチオン性ポリマー添加濃度（ｍｇ／Ｌ）＋無機凝集剤添加濃度（ｍｇ／Ｌ）×β　　…（Ｉ）
    　　α：水質変動を加味した安全係数
    　　β：無機凝集剤のカチオン量をカチオン性ポリマーのカチオン量に換算する係数     By titrating the water to be treated with the cationic polymer by the streaming potential method, the required amount of the cationic polymer necessary for neutralizing the charge of the water to be treated is obtained as the cation consumption A, and the inorganic The method further comprises means for controlling the addition amount of the cationic polymer and the addition amount of the inorganic flocculant so that the addition concentration of the flocculant and the cationic polymer satisfies the following relational expression (I): The water treatment apparatus according to any one of 9.
    Cation consumption A × α =
    Cationic polymer addition concentration (mg / L) + Inorganic flocculant addition concentration (mg / L) × β (I)
    α: Safety factor taking into account fluctuations in water quality β: Factor for converting the cation amount of the inorganic flocculant into the cation amount of the cationic polymer
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