JP2014158996A - Water treatment method utilizing filter aid concentration management device, water treatment device, and filter aid concentration management device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To utilize adsorbing performance of a filter aid inexpensively at a maximum when removing suspended substance etc., from water to be treated such as waste water using a filter aid.SOLUTION: A water treatment method comprises a first step of forming a precoat layer of a filter aid by supplying the filter aid onto a filter having a horizontal plane over an installation plane, in a solid-liquid separation device which includes the filter and has its internal space divided by the filter into an upper and a lower part from a filter aid storage tank through a filter aid supply line. Further, the water treatment method comprises: a second step of capturing and removing suspended substance in water to be treated through the precoat layer by supplying the water to be treated to the precoat layer in the solid-liquid separation device through a water-to-be-treated supply line; and a third step of measuring a concentration of the filter aid by a filter aid concentration management device arranged in the filter aid storage tank.

Description

  Embodiments described herein relate generally to a water treatment method, a water treatment device, and a filter aid concentration management device that use a filter aid concentration management device.

  In recent years, effective use of water resources is required due to industrial development and population growth. For that purpose, reuse of wastewater such as industrial wastewater is very important. In order to achieve these, it is necessary to purify the water, ie to separate other substances from the water.

  Various methods are known as methods for separating other substances from the liquid, such as membrane separation, centrifugation, activated carbon adsorption, ozone treatment, aggregation, and removal of suspended solids by a predetermined filter aid. Can be mentioned. By such a method, chemical substances having a great influence on the environment such as phosphorus and nitrogen contained in water can be removed, and oils and clays dispersed in water can be removed.

  Of these, membrane separation is one of the most commonly used methods. However, when oils dispersed in water are removed, the pores of the membrane are likely to be clogged with oil, which shortens the life of the membrane. There is a problem that it is easy. For this reason, membrane separation is often not appropriate for removing oils in water.

  Therefore, as a method of removing them from water containing oils such as heavy oil, for example, the floating property of heavy oil based on the difference in specific gravity between water and heavy oil is used, and water is removed by an oil fence installed on the water. A method of collecting heavy oil floating on the surface of the water, sucking and collecting from the surface, or a method of laying a hydrophobic material having an adsorptivity to heavy oil on the water and adsorbing the heavy oil for recovery .

  On the other hand, in recent years, attempts have been made to remove suspended solids in wastewater by a pressure levitation method or a coagulation sedimentation method. However, in the pressurized flotation method, agglomerated polymer is added to the wastewater to coarsen the suspended matter in the wastewater, and the suspended matter is floated as a floc on the surface of the wastewater by blowing in compressed air. More separated and removed. In this case, since a large amount of agglomerated polymer is required, there is a problem that the cost of chemicals increases and as a result, the cost of wastewater treatment increases (Patent Document 1).

  In addition, the coagulation sedimentation method has a problem in that the cost of chemical treatment increases due to the use of a large amount of various metal salts, and the treatment of sludge generated in large amounts is also necessary, which increases the cost of wastewater treatment. .

  Furthermore, an attempt is made to adsorb oil to the filter aid and remove it from the water by immersing it in water in which suspended substances such as oil are dispersed using a filter aid. For example, Patent Document 2 discloses a method of removing suspended substances using porous powder. However, in this method, when the filter aid is used repeatedly, there is a problem that the filter aid is mixed with sludge and discharged from the system, and the concentration of the filter aid cannot be grasped. In addition, when used repeatedly, impurities in the water are mixed in the filter aid tank, which makes it difficult to control the concentration.

JP 2006-218381 A JP 2012-55784 A

  The problem to be solved by the present invention is that when removing suspended substances such as suspended substances by repeatedly using a filtration aid containing magnetic substances from the water to be treated such as wastewater, appropriate concentration management of the filter aid is performed. It is to provide a water treatment method and a concentration management device.

  The water treatment method of the embodiment includes a filter having a plane parallel to the installation surface through a filter aid supply line from a filter aid storage tank that stores a filter aid containing a magnetic substance. A first step of forming the precoat layer made of the filter aid by supplying the filter aid onto the filter in the solid-liquid separator whose internal space is divided vertically. A second step of supplying water to be treated to the precoat layer in the solid-liquid separator via the water to be treated supply line, and trapping and removing suspended substances in the water to be treated by the precoat layer; And a third step of measuring the concentration of the filter aid in a filter aid concentration management device disposed on the filter medium storage tank.

It is a schematic block diagram of the water treatment apparatus in 1st Embodiment. It is a figure which expands and shows the filter aid density | concentration management apparatus of the water treatment apparatus shown in FIG. It is a figure which shows schematic structure of the filter aid concentration sensor in the filter aid concentration management apparatus shown in FIG. It is a figure which shows schematic structure of the filter aid concentration sensor in the filter aid concentration management apparatus shown in FIG. It is explanatory drawing for measuring the density | concentration of a filter aid using the filter aid density | concentration management apparatus shown in FIG.

  First, the filter aid used in the water treatment method, the water treatment device, and the filter aid concentration management device in the embodiment will be described.

  The filter aid in this embodiment is, for example, iron and an alloy containing iron, magnetite, titanite, pyrrhotite, magnesia ferrite, manganese magnesium ferrite, manganese zinc ferrite, cobalt ferrite, nickel ferrite, nickel zinc ferrite, barium ferrite, It contains a magnetic material such as copper zinc ferrite, and can be constituted directly from these magnetic particles.

Among the above-described particles, magnetic particles made of a ferrite compound having excellent stability in water are more preferable. For example, magnetite (Fe ₃ O ₄ ), which is a magnetite, is preferable because it is not only inexpensive, but also stable as a magnetic substance in water and safe as an element, so that it can be easily used for water treatment.

  In this case, the above-described particles can take various shapes such as a spherical shape, a polyhedron, and an irregular shape, but are not particularly limited. Further, a desirable particle size and shape may be appropriately selected in consideration of manufacturing costs.

  In particular, when the magnetic particles have an acute angle, in the recovery process of the filter aid by magnetic force as described below, as long as the magnetic force acts on the magnetic particles and the filter aid can be regenerated by the magnetic force, Cu plating, It is also possible to round the acute angle by using a normal plating process such as Ni plating or a surface treatment for the purpose of preventing corrosion.

  The case where the filter aid is made of magnetic particles will be described in detail. The size of the filter aid varies depending on the magnetic force of the processing equipment, the flow velocity, the trapping method, the density of the magnetic particles, and various conditions. However, the average particle diameter of the magnetic particles in the present embodiment is generally 0.1 to 100 μm, preferably 0.3 to 50 μm. If the lower limit value of the magnetic particles is smaller than 0.1 μm, the magnetic particles can be densely aggregated to remove fine suspended solids in the water, but there are cases where a practical amount of water flow cannot be obtained. When the upper limit value of the magnetic particles is larger than 100 μm, the distance between the particles increases, and the suspended matter in water to be removed may not be sufficiently removed.

  In addition, the measurement method of the average particle diameter of magnetic particles can be measured by a laser diffraction method. Specifically, it can be measured by a SALD-3100 type measuring device (trade name) manufactured by Shimadzu Corporation. Can do. In addition, when the term “average particle diameter” appears below and specific numerical values are described, the “average particle diameter” is determined by the laser diffraction method as described above, unless otherwise described. It is measured.

  Furthermore, it is not necessary for all of the filter aids to be composed of magnetic particles. That is, when the filter aid contains magnetic particles, magnetic force acts between these magnetic particles, and as long as the filter aid can be recovered by the magnetic force, styrene resin, water-added styrene resin, butadiene resin, isoprene resin, acrylonitrile resin , Cycloolefin resin, phenol resin, alkyl methacrylate resin, fluororesin and other binders may be used. The surface of the magnetic particles may be bonded with an alkoxysilane compound such as methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, or phenyltriethoxysilane.

  In this case, when the average particle diameter of the above-described magnetic particles is a (μm) and the average particle diameter of the aggregate obtained by bonding with the above-described resin or silane coupling agent is b (μm), a <B ≦ 20a is preferable, and a <b ≦ 8a is more preferable. When the latter condition is satisfied, the magnetic particles do not aggregate into a spherical shape to form an aggregate, and an aggregate having an irregular shape can be obtained.

  Therefore, by using such an agglomerate as a filter aid, when a precoat layer to be described later is formed by the filter aid, the precoat layer has appropriate voids. Can be sufficiently captured and removed, and a sufficient amount of water can be secured. In order to obtain the effect, it is particularly preferable to satisfy the relationship of a <b ≦ 5a.

  Moreover, when the said aggregate is comprised using resin as a binder, it is preferable that the thickness c of the resin layer which comprises the skin of an aggregate is 0.01 micrometer or more and 0.25 micrometer or less. If the thickness c of the resin layer is smaller than 0.01 μm, the strength of the agglomerates may be reduced, making it difficult to use as a filter aid, and the thickness c of the resin layer is less than 0.25 μm. If it is too large, the gap between the aggregates becomes narrow, and when used as a filter aid, an effective water flow rate may not be ensured.

  The thickness c of the resin layer can be obtained by observing with an optical microscope, SEM, or the like. Preferably, the aggregate is heated to a predetermined temperature in an oxygen-free state to thermally decompose the aggregate. The amount of resin coating can be obtained from the weight reduction amount at the time, and the average value of the resin coating amount can be derived from the specific surface area of the aggregate.

  The filter aid of this embodiment can be produced by any method as long as the above-described requirements are satisfied. For example, when the filter aid is composed of magnetic particles, commercially available magnetic particles that satisfy the above average particle diameter can be used as they are.

  When the filter aid is composed of the agglomerates described above, it can be obtained by, for example, dissolving or dispersing magnetic particles and resin in an organic solvent and spraying the obtained solution or dispersion medium by a spray drying method or the like. Can do. According to this method, the average particle diameter of the aggregate can be adjusted by adjusting the environmental temperature of spray drying, the ejection speed, etc., and pores are formed when the organic solvent is removed from the aggregate. Aggregates can also be formed.

  On the other hand, in order to industrially produce a filter aid for aggregates, for example, a solution obtained by dissolving a resin or the like is poured into a mold or the like previously filled with magnetic particles, and the solvent is removed and solidified. The above-mentioned filter aid can be obtained by crushing, or by crushing a composition obtained by dispersing an organic solvent in a polymer solution and then solidifying it. In addition, after the magnetic particles are put in a Henschel mixer, a ball mill, a granulator, etc., a solution or dispersion medium obtained by dissolving or dispersing a resin or the like in an organic solvent is dropped into the above apparatus and dried, and then the above-described method is performed. Such a filter aid can also be obtained.

(Water treatment apparatus and water treatment method)
Next, the water treatment apparatus and the water treatment method of this embodiment will be described.

(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of a water treatment device of the present embodiment, and FIG. 2 is an enlarged view of a filter aid concentration management device of the water treatment device shown in FIG. 3 and 4 are diagrams showing a schematic configuration of the filter aid concentration sensor in the filter aid concentration management apparatus shown in FIG. 2, and FIG. 5 uses the filter aid concentration management apparatus shown in FIG. It is explanatory drawing for measuring the density | concentration of a filter aid.

  As shown below, in this embodiment, a filter aid regeneration tank and a regenerated filter aid supply line are arranged, and the case where the used filter aid is washed and regenerated and reused is described. These components can be deleted as appropriate, and accordingly, cleaning and regeneration of the used filter aid can be omitted. However, by arranging the above-mentioned filter aid regeneration tank and regenerated filter aid supply line, it is possible to wash and regenerate used filter aid without supplying a large amount of new filter aid. Thus, it is possible to provide a water treatment apparatus and a water treatment method capable of operating for a long time by effectively using the filter aid initially introduced.

  A water treatment device 10 shown in FIG. 1 includes a filtration aid storage tank 11 for storing a filtration aid, a treated water storage tank 12 for temporarily storing treated water W1 containing floating substances, and filtration. It includes a filter 131 that is located downstream of the auxiliary material storage tank 11 and the treated water storage tank 12 and has a horizontal surface with respect to the installation surface, and the internal space is divided into upper and lower parts 13A and 13B by the filter 131. A liquid separator 13. Stirrers 111 and 121 are disposed in the filtration aid storage tank 11 and the treated water storage tank 12, respectively.

  Examples of the suspended substance in the present embodiment include aquatic, serinite, other organic substances such as microorganisms, alumina, and iron hydroxide.

  In addition, since the precoat layer 132 made of a filter aid to be formed later becomes uniform by making the filter 131 in the solid-liquid separator 13 horizontal with the installation surface, a stable amount of water and water quality can be obtained.

  The filter aid storage tank 11 and the solid-liquid separation device 13 are connected by a pump 44 and pipes 36 and 24. As will be described below, the pump 44 and the pipes 36 and 24 are supplied with a filter aid. Configure the line.

  Moreover, the to-be-processed water storage tank 12 and the solid-liquid separation apparatus 13 are connected by the piping 24 via the pump 42, and these pump 42 and the piping 24 are the to-be-processed water supply line so that it may demonstrate below. Configure.

  A pipe 21 constituting a filter aid supply line is arranged at the upper part of the filtration aid storage tank 11, and a pipe 23 constituting a treated water introduction line is arranged at the upper part of the treated water storage tank 12. Has been. A pipe 26 constituting a washing water supply line is connected to the upper part 13A of the solid-liquid separator 13.

  In addition, a regeneration tank 14 for regenerating the used filter aid is disposed on the downstream side of the solid-liquid separation device 13. The regeneration tank 14 is provided along the stirrer 141 and the side surface. An electromagnet 142 is provided. The solid-liquid separator 13 and the regeneration tank 14 are connected by a pipe 27 constituting a filter aid recovery line. Further, the regeneration tank 14 and the solid-liquid separator 13 are connected to each other by a pipe 36 via a pump 44 through the filter aid storage tank 11.

  The container shape, capacity, material, and the like of the treated water storage tank 12 are not particularly limited, but preferably have a capacity that allows at least a residence time of 15 minutes. In addition, it is preferable to prevent the treated water W1 from being short-cut from the supply pipe 23 to the pipe 24 by providing a baffle plate in the treated water storage tank 12.

  Further, a filter aid concentration management device 17 is disposed on the filter aid storage tank 11. The filter aid storage tank 11 and the filter aid concentration management device 17 are connected by a pipe 37. Further, a pump 45 is disposed in the pipe 37.

  As shown in FIG. 2, the filter aid concentration management device 17 includes a filter aid temporary storage tank 171 for temporarily storing a filter aid slurry, and a filter disposed in the filter aid temporary storage tank 171. An auxiliary material concentration sensor 172, a magnetic separation device 173, and a stirrer 174 are included. In addition, a valve 48 is disposed below the filter aid temporary storage tank 171, and the filter aid after measurement of the amount (concentration) of the filter aid is returned to the filter aid storage tank 11. Yes.

  The filter aid concentration sensor 172 can be any of a microwave type, a radiation type, and an optical type. In the case of the microwave-type and radiation-type filter aid concentration sensor 172, for example, as shown in FIG. 3, a transmitting portion 172B and a receiving portion 172C are arranged opposite to each other at the distal end portion of the bridge beam-like member 172A, and the receiving portion 172A is connected to the receiving portion. Microwave or γ-ray is transmitted toward 172C, and the concentration of the target substance is measured from the intensity change of the microwave or γ-ray in the receiving unit 172C.

  In the case of the optical-type filter aid concentration sensor 172, for example, as shown in FIG. 4, in the concave portion of the U-shaped member 172E, the transmitting unit 172F and the receiving unit 172G are arranged to face each other, and the transmitting unit 172F to the receiving unit Light of a predetermined wavelength is transmitted toward 172G, and the concentration of the target substance is measured from the change in the intensity of light in the receiver 172G.

Next, a water treatment method using the water treatment apparatus 10 shown in FIG. 1 will be described.
First, the filter aid is supplied from the pipe 21 into the filter aid storage tank 11, and the slurry-like filter aid is adjusted in the filter aid storage tank 11. In addition, in order to adjust a slurry-form filter aid, it is performed using the stirrer 111 arrange | positioned in the filter aid storage tank 11 suitably.

  Next, the filter aid is supplied from the filter aid storage tank 11 to the filter 131 of the solid-liquid separator 13 through the filter aid supply line, that is, the pump 44 and the pipes 36 and 24, and the filter 131 is filtered. A precoat layer 132 made of an auxiliary material is formed. In addition, in order to form the precoat layer 132, the opening of the filter 131 is set to such a size that the filter aid does not penetrate the filter 131. Further, the thickness of the precoat layer 132 is not particularly limited as long as suspended substances in the water to be treated are captured and removed, and further depends on the size and porosity of the filter aid, for example, 0.1 mm to It can be 10 mm.

  Subsequently, the to-be-processed water W1 containing a floating substance is introduce | transduced in the to-be-processed water storage tank 12 from the piping 23 which is a to-be-treated water introduction line. Then, after stirring with the stirrer 121 as necessary to disperse the suspended solids in the water to be treated W1 uniformly, the water to be treated is supplied through the pump 42 and the pipe 24 that are the water to be treated. W1 is supplied to the precoat layer 132 formed on the filter 131 in the solid-liquid separator 13.

  At this time, suspended substances contained in the water to be treated W1 are captured and removed by the filter aid constituting the precoat layer 132. The water that has passed through the precoat layer 132 and the filter 131 of the solid-liquid separator 13 is discharged to the outside from the pipe 28 as treated water W2.

  Washing is performed before a predetermined time elapses and the amount of trapped suspended matter in the water to be treated W1 in the filter aid constituting the precoat layer 132 increases and trapped suspended matter is not captured. This control is performed by monitoring the filtration time, water flow pressure, water flow rate, filtration flow rate, and the like. For example, when controlling by the filtration flow rate, when the filtration flow rate of the precoat layer 132 and the filter 131 becomes 2 m / h or less, for example, the washing is performed from the pipe 26 serving as the washing water supply line to the upper portion 13A of the solid-liquid separation device 13. Water W3 is supplied, the filter aid constituting part or all of the precoat layer 132 is peeled off, and introduced into the regeneration tank 14 from the pipe 27 constituting the filter aid recovery line. The treated water W2 discharged from the pipe 28 can be used alone as the cleaning water W3, or can be mixed with tap water or the like and used as the cleaning water W3.

  In the regeneration tank 14, an organic solvent such as ethanol, methanol, propanol, isopropanol, hexane, and acetone, an anionic surfactant, a cationic surfactant, and a nonionic surfactant are supplied from a pipe 31 that is a washing water supply line. A cleaning liquid such as is supplied to wash suspended substances trapped in the filter aid. At this time, by driving the stirrer 141, a shearing force due to the cleaning liquid acts on the filter aid, so that the suspended matter can be efficiently removed from the filter aid.

  Further, since the filter aid contains a magnetic substance, it can be recovered using the electromagnet 142, whereby the cleaning liquid containing suspended solids can be easily recovered and discharged from the pipe 35. Moreover, when water is supplied from the pipe 32 which is a water supply line and the electromagnet 142 is turned off, a slurry solution of a filter aid is obtained. In addition, although the electromagnet is used in the reproduction | regeneration tank 14, it can also be used by using a permanent magnet which has a cylindrical cover, and raising / lowering a permanent magnet with motive power, such as an air cylinder.

  This slurry solution is transferred to the filter aid storage tank 11, supplied from the filter aid storage tank 11 to the solid-liquid separator 13 as described above, and used again to form the precoat layer 132. And as above-mentioned, the to-be-processed water W1 is supplied on the precoat layer 132, adsorption removal of a floating substance, washing | cleaning of the filter aid which comprises the precoat layer 132, regeneration of the filter aid, etc. are performed. Then, by repeatedly performing the above-described operation, it is possible to continuously remove suspended substances in the water to be treated W1.

  On the other hand, when the above operation is repeated, for example, the filter aid is mixed into the treated water W2 discharged from the pipe 28 and discharged to the outside, and the filter aid in the water treatment apparatus 10 shown in FIG. The amount (concentration) of the material may be lower than the amount (concentration) of the filter aid initially introduced.

  Therefore, in this embodiment, the amount (concentration) of the filter aid in the filter aid reservoir 11 is measured by the filter aid concentration management device 17 disposed on the filter aid reservoir 11.

  Specifically, a part of the filter aid slurry in the filter aid storage tank 11 is pulled up to the filter aid temporary storage tank 171 of the filter aid concentration management device 17 by the pump 45 through the pipe 37, and the agitator 174. Then, the amount (concentration) of the slurry stored in the filter aid temporary storage tank 171 is measured by the filter aid concentration sensor 172, and the concentration at that time is A. Next, after driving the magnetic separation device 173 to fix the filter aid in the slurry outside the detection range of the filter aid concentration sensor 172, the amount (concentration) of the remaining slurry is measured by the filter aid concentration sensor 172. The density at that time is B.

  Therefore, the amount (concentration) of the filter aid in the slurry stored in the filter aid temporary storage tank 171, that is, the filter aid slurry stored in the filter aid storage tank 11 is derived from AB. be able to. In this case, the concentration A mainly corresponds to the concentration of the suspended matter filter aid that cannot be separated by the filter aid and the regeneration tower 14 and adheres to the filter aid, and the concentration B represents the suspended matter excluding the filter aid. Corresponds to concentration.

  The amount (concentration) of the filter aid can be directly obtained as the difference between the concentration A and the concentration B measured as described above, but the calibration curve and the measurement curve based on the actual measurement value of the concentration A as shown in FIG. Is used, the exact amount (concentration) of the filter aid can be determined. Note that the calibration curve in FIG. 5 is derived in advance by storing only the filter aid in the filter aid temporary storage tank 171 using the filter aid concentration management device 17 and measuring it with the filter aid concentration sensor 172. is there. 5 is the filtration aid concentration management device 17 when the water treatment device 10 shown in FIG. 1 is driven using the amount (concentration) of the filtration aid shown in the horizontal axis of FIG. It is the graph obtained by measuring a filter aid.

  In FIG. 5, the output value of the filter aid concentration management device 17, that is, the filter aid concentration sensor 18 increases as the amount (concentration) of the filter aid increases in both the calibration curve and the actual measurement line. .

  In FIG. 5, since the intercept of the measured line, that is, the output value when the concentration of the filter aid is 0%, corresponds to the concentration B of suspended solids adhering to the filter aid, the concentration B is shown in FIG. The concentration of the filter aid during the measurement of the concentration A can be obtained by driving the water treatment device 10 shown and subtracting it from the actual measured value of the concentration A of the filter aid in the filter aid concentration management device 17. .

  On the other hand, the amount (concentration) of the filter aid in the water treatment apparatus 10 shown in FIG. 1 is lower than the amount (concentration) of the filter aid initially charged, and becomes lower than the initial set value. When the value is out of the value, the suspended matter in the water to be treated W1 cannot be sufficiently removed even when the water treatment apparatus 10 is driven and the water to be treated W1 is treated. For example, when the amount (concentration) of the filter aid necessary for driving the water treatment apparatus 10 shown in FIG. 1 is 1.5 wt% to 2.5 wt% as shown in FIG. Thus, when the quantity (concentration) of the filter aid measured is out of the range of the set value, suspended substances in the for-treatment water W1 cannot be sufficiently removed.

  In such a case, it is preferable that the filter aid concentration management device 17 emits a predetermined signal such as a warning light or a warning sound from a lamp or a speaker (not shown). Thereby, the operator can know that the amount (concentration) of the filter aid in the water treatment device 10 is lower than the set value, and the filter aid is put into the filter aid storage tank 11 from the pipe 21. The amount (concentration) of the filter aid supplied to the solid-liquid separation device 13 from the filter aid storage tank 11 through the pipe 36, that is, the amount (concentration) of the filter aid in the water treatment device 10 is a set value. Can be adjusted within.

  In this example, the water treatment apparatus 10 shown in FIG. 1 was used. As the filter aid, manganese magnesium ferrite having an average particle diameter of 15 μm was used, and slurry containing 200 mg / L of alumina particles having an average particle diameter of 0.1 μm as SS was used as the water to be treated W1.

  First, the slurry of manganese magnesium ferrite is supplied to the solid-liquid separator 13 to form the precoat layer 132 on the filter 131, and then the slurry concentration transferred to the filter aid storage tank 11 is controlled by the filter aid concentration control. The measurement was performed by the optical concentration sensor 172 in the apparatus 17, and the calibration curve of the slurry was obtained. When the concentration was X wt% and the output value was Y, Y = 0.665X. Based on this calibration curve, the set value of the magnetic material in the water treatment apparatus 10 was set to the range of the sensor output value of 1.76 to 2.15 (concentration of 2.7 to 3.3 wt%).

  Next, the magnetic substance is adjusted in the filter aid storage tank 11 so that the slurry concentration becomes 3% by weight, and this slurry is supplied to the solid-liquid separator 13 using the pump 44, and is thick on the filter 131. A precoat layer 132 having a thickness of 1 mm was formed. Thereafter, the slurry concentration transferred from the filter aid storage tank 11 to the filter aid concentration management device 17 was measured by the optical concentration sensor, and the value A was obtained. Further, the value of the optical concentration sensor after the electromagnet 173 was operated to collect all the filter aid in the filter aid concentration management device 17 was defined as B.

  Thereafter, the washing water W3 was supplied to the precoat layer 132, the filter aid constituting the precoat layer 132 and the removed SS were transferred to the regeneration tank 14, and only the magnetic material was recovered with the electromagnet 142 while stirring. Next, after the SS concentrated water was discharged, the electromagnet 142 was turned off to make a magnetic slurry using a part of the treated water and returned to the filter aid storage tank 11. In the first density control, A = 1.95, B = 0, and AB = 1.95, which was within the set value range.

  When this was repeatedly tested, SS alumina particles began to be mixed in the magnetic slurry. When the test was performed 20 times, A = 2.14, B = 0.20, and A−B = 1.94, which was the set value range.

  From the above, it was found that the concentration of the magnetic slurry can be managed by the water treatment device 10, the filter aid concentration management device 17 and the water treatment method shown in the embodiment.

  As mentioned above, although several embodiment of this invention was described, these embodiment was posted as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 Water treatment apparatus 11 Filtration aid storage tank 111 Stirrer 12 To-be-treated water storage tank 121 Stirrer 13 Solid-liquid separator 131 Filter 132 Precoat layer 14 Regeneration tank 141 Stirrer 142 Electromagnet 17 Filtration aid concentration management apparatus 171 Filtration aid temporary storage Tank 172 Filter aid concentration sensor 173 Magnetic separator 174 Stirrer 21, 23, 24, 26-28, 31, 32, 35-37 Piping 42, 44, 45 Pump

Claims (8)

From the filter aid storage tank for storing the filter aid containing magnetic substance, through the filter aid supply line, a filter having a plane parallel to the installation surface is included, and the internal space is divided up and down by the filter. A first step of supplying the filter aid on the filter in the solid-liquid separator, and forming a precoat layer made of the filter aid;
A second step of supplying water to be treated to the precoat layer in the solid-liquid separation device via a water to be treated supply line, and capturing and removing floating substances in the water to be treated by the precoat layer;
A third step of measuring the concentration of the filter aid in the filter aid concentration management device disposed on the filter medium storage tank;
A water treatment method comprising the steps of: The filter aid management device includes a filter aid temporary storage tank that temporarily stores the filter aid slurry, a filter aid concentration sensor, a stirrer, and a magnetic separator disposed in the filter aid temporary storage tank. Including equipment,
In the third step, the concentration of the filter aid is stored in the filter aid temporary storage tank, the slurry concentration measured by the filter aid concentration sensor is A, and the magnetic separation device When the filter aid is fixed outside the detection region of the filter aid concentration sensor, stored in the filter aid temporary storage tank, and the slurry concentration measured by the filter aid concentration sensor is B The water treatment method according to claim 1, wherein the water treatment method is derived from AB.   The water treatment method according to claim 2, wherein when the concentration A-B of the filter aid changes from a set value, the filter aid concentration management device issues a predetermined signal.   A fourth step of supplying cleaning water to the precoat layer, transferring the used filter aid to the regeneration tank via the used filter aid supply line, washing and regenerating in the regeneration tank; The water treatment method according to any one of claims 1 to 3, wherein A filter aid concentration management device used for water treatment of water to be treated containing suspended solids,
Arranged on a filter aid storage tank for storing a filter aid containing a magnetic substance,
A filter aid temporary storage tank for temporarily storing the slurry of the filter aid, a filter aid concentration sensor disposed in the filter aid temporary storage tank, a stirrer, and a magnetic separator; A filter aid concentration control device.   The concentration of the filter aid is stored in the filter aid temporary storage tank, the concentration of the slurry measured by the filter aid concentration sensor is A, and the filter aid is filtered by the magnetic separator. Derived from AB when the concentration of the slurry stored in the filter aid temporary storage tank after being fixed outside the detection region of the concentration sensor and measured by the filter aid concentration sensor is B. The filter aid concentration management device according to claim 5, wherein   The filter aid concentration management apparatus according to claim 5 or 6, wherein a signal is generated when the concentration A-B of the filter aid changes from a set value.   A water treatment apparatus comprising the filter aid concentration management apparatus according to any one of claims 5 to 7.

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