JP2001157894A - Water cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preventing a clogging phenomenon while using a membrane separation method in order to reuse water and preventing the lowering of the transmissivity of a membrane and the lowering of the life of an ion exchange resin caused by the deposition of silicic acid while using a membrane separation method and an ion exchange resin in making high purity water. SOLUTION: A combined method of an electrolytic flocculation method and a membrane separation method is used in order to reuse waste water. That is, water to be treated is passed through an electrolytic flocculation apparatus performing electrolysis using an aluminum electrode and an iron electrode and subsequently guided to a microporous or porous membrane or a reverse osmosis membrane to be passed therethrough to be cleaned. A combined method of an electrolytic flocculation method and a membrane separation method same to that used in order to reuse waste water or a combined method of an electrolytic flocculation method and an ion exchange resin is used in order to obtain high purity water from tap water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying water for purifying and reusing industrial wastewater, domestic wastewater and the like, or for obtaining high-purity water. .

[0002]

2. Description of the Related Art In order to purify industrial wastewater, domestic wastewater and the like, a coagulation sedimentation method using chemicals such as aluminum sulfate and iron sulfate and an activated sludge method using microorganisms have become widespread. Furthermore, in order to increase the cleanliness to such an extent that water can be reused, a membrane separation method of permeating a porous membrane having many fine pores or a reverse osmosis membrane may be used. As a method for obtaining high-purity water, there are methods such as permeation through a reverse osmosis membrane and removal of ions by an ion exchange resin.

[0003]

A membrane separation method for permeating a porous membrane having a large number of fine pores or a reverse osmosis membrane in order to purify and reuse industrial wastewater and domestic wastewater is useful. In general, clogging with fine particles in water, generation of microorganisms on the membrane surface, deposition of silicic acid, calcium carbonate, etc. on the membrane surface, etc., decrease the water permeability. It has become a major obstacle to the promotion of employment.

An object of the present invention is to provide a method for preventing clogging while using a membrane separation method for recycling water.

In order to obtain high-purity water from tap water, a membrane separation method and an ion-exchange resin are effective. In this case, in particular, a decrease in the transmittance due to the deposition of a silicic acid component on the membrane surface and an increase in the ion-exchange resin The problem is that the life of the ion-exchange resin is reduced due to the adhesion of silicic acid to the membrane. Therefore, in the production of high-purity water, the present invention uses a membrane separation method and ion-exchange resin to reduce the permeability of the membrane due to the deposition of silicic acid. Another object of the present invention is to provide a method for preventing the deterioration and the life of the ion exchange resin.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an electro-coagulation method and a membrane, which have been found by experiments of the present applicant to have an effect of agglomerating fine particles and a high ability to remove silicic acid in order to reuse waste water. A method combining separation methods is used.

That is, the water to be treated is passed through an electrolytic aggregating apparatus that performs electrolysis using aluminum and iron as electrodes, and then guided to a porous membrane or reverse osmosis membrane having fine pores, where water is permeated and cleaned.

[0008] In order to obtain high-purity water from tap water, a method combining the electrolysis coagulation method and the membrane separation method as in the case of recycling wastewater is used, or a combination of the electrolysis coagulation method and an ion exchange resin is used. Method.

In particular, prior to electrocoagulation to increase the efficiency of electrocoagulation, the water to be treated is separated into acidic water and alkaline water by electrodialysis, and the acid water is led to an electrocoagulation apparatus to perform electrolysis. The water discharged from the coagulation device is combined with the alkaline water.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for purifying water while preventing deterioration of a membrane or an ion exchange resin by combining an electrolytic coagulation tank and an ion exchange membrane or an ion exchange resin has been realized.

[0011]

FIG. 1 shows an embodiment according to claim 1 of the present invention. In this method, water to be treated is introduced from a water inlet (9) to be treated by using an electrolytic coagulation tank (1), a filter (4), a high-pressure pump (5), a reverse osmosis membrane tank (6), and the like.
The fine particles and the silicic acid component in the water to be treated are agglomerated in the electrolysis agglutination tank (1), the agglomerated matter is collected in a filter (4), and the water permeated through the filter is pressurized by a high-pressure pump (5) to form a reverse osmosis membrane After passing through 6), ionic and other impurity components are removed, and the purified water is taken out from the purified water outlet.

A part of the water in which the impurities are concentrated in the reverse osmosis membrane (6) is returned to the electrolytic coagulation tank. In the figure, an electrolysis coagulation tank (1) is a water tank in which positive and negative voltages from a DC power supply (16) are arranged on a plate-shaped aluminum or iron anode (2) and a cathode (3). When a voltage is applied to the DC power supply while water is introduced, aluminum or iron at the anode is eluted into the water to become aluminum hydroxide or iron hydroxide and, at the same time, aggregate fine particles and silicic acid.

FIG. 2 shows an embodiment according to claim 2 of the present invention. In this method, water to be treated is introduced into the electrolytic coagulation tank (1) from the water inlet (9) using the electrolysis coagulation tank (1), the filter (4), the ion exchange resin tank (21), and the like. Agglomerates fine particles and silicic acid components in the water to be treated, collects the aggregates in a filter (4), and removes ionic components in the water that has passed through the filter in an ion exchange resin tank (21) for purification. I do.

FIG. 3 shows an embodiment according to claim 3 of the present invention. This method uses a diaphragm type electrolysis tank (17), an electrolysis coagulation tank (1), a filter (4), and the like, and introduces water to be treated from a water inlet part (9) to be treated. 17) across the porous membrane (18) in the anode (1).
9) and a voltage is applied to the cathode (20) by a DC power supply (16) to separate the water to be treated into an acidic water (14) and a basic water (15), and the acidic water is electrolyzed and coagulated (1).
To agglomerate the fine particles and the silicic acid component in the water to be treated, add basic water (15) to the water discharged from the electrolytic coagulation tank (1) to promote the coagulation, and use the filter (4) to filter the coagulated components. Purify the water by removing water.

FIG. 4 shows an embodiment according to claim 4 of the present invention. This method uses an electro-coagulation tank (1), a filter (4), a high-pressure pump (5), a reverse osmosis membrane tank (6), a diaphragm type electro-lysis tank (17), and the like, and a water inlet (9) to be treated. Water to be treated is introduced, and the electrolysis coagulation tank (1)
The fine particles and the silicic acid component in the water to be treated are aggregated, and the aggregate is collected in a filter (4), pressurized by a high-pressure pump (5), and ionic and other impurity components are removed by a reverse osmosis membrane (6). Then, the purified water is taken out from the purified water outlet. The water enriched in impurities by the reverse osmosis membrane (6) is led to a diaphragm type electrolysis tank (17) to be separated into basic water and acidic water, the basic water is discarded, and the acidic water is returned to the electrolysis coagulation tank. In this way, the water to be treated (1
The liquid property of 0) is kept on the acidic side.

FIG. 5 shows an embodiment according to claim 5 of the present invention. As an electrolytic coagulation tank, an anode and a cathode made of a plate-shaped conductive material are placed parallel to each other, and between the anode and the cathode, there is no electrical connection with either the anode or the cathode. The electrolysis coagulation tank in which the intermediate electrode (23) is arranged in parallel with the anode and the cathode is used.

FIG. 6 shows an embodiment according to claim 6. An anode and a cathode made of a plate-like conductive material are placed as an electrolysis coagulation tank, and a strip of iron or aluminum (24) is filled between the anode and the cathode, and a large number of irregularly shaped iron or aluminum are placed. Each of the materials has an electrically insulating portion covered with an oxide, a coating, an insulating film, or the like on a part of the surface.

FIG. 7 shows an embodiment according to claim 7. An anode and a cathode made of a plate-like or mesh-like conductive material are placed in parallel in a water tank, and there is no electrical connection between the anode and the cathode between the anode and the cathode by the conductive material. An electrolytic coagulation tank having a structure in which intermediate electrodes including (25) and an aluminum plate (26) are arranged is used.

FIG. 8 shows an embodiment according to the eighth aspect. An anode and a cathode made of a plate-like conductive material are placed, and a metal strip containing both iron (27) and aluminum (28) is filled between the anode and the cathode. Has an electrically insulating property in which a part of the surface is individually covered with an oxide, a coating, an insulating film, or the like.

FIG. 9 shows an embodiment according to claim 9. In a water tank, a plurality of anodes and cathodes made of a plate-like or mesh-like conductive material are alternately placed in parallel, and the anodes are made of iron (2).
9) and aluminum (30).

FIG. 10 shows an embodiment according to the tenth aspect. An anode and a cathode made of plate-shaped conductive material are placed,
The surfaces of the anode and the cathode are coated on opposite sides with a porous insulating film (31), and a large number of both iron and aluminum are placed between the films covering the anode and the cathode. Is filled.

FIG. 11 shows an embodiment according to the eleventh aspect. The water to be treated is subjected to a coagulation treatment using an iron plate (33) as a metal material for coagulation, and then treated using an electrolysis coagulation bath using an aluminum plate (34) as a metal material for coagulation.

FIG. 12 shows an embodiment according to the twelfth aspect. 1 shows a water purification method similar to that of FIG. 1, but an alternating current power supply (37) in which the electrical polarity of a cathode and an anode is periodically inverted is used instead of a DC power supply as a power supply for an electrolytic coagulation tank. .

FIG. 13 shows an embodiment according to claim 13. As a filling material between the anode and the cathode in the electrolysis coagulation tank, particularly, the material is iron or aluminum, and both surfaces of a plate-like material (38, 39) are covered with an insulating film (41);
Shows a packing (42) made by chopping it into square pieces.

FIG. 14 shows an embodiment according to claim 14 of the present invention. In this method, water to be treated is introduced from a water inlet (9) to be treated using an electrolysis coagulation tank (1), a filter (4), a high-pressure pump (5), a reverse osmosis membrane tank (6), and the like. The fine particles and the silicic acid component in the water to be treated are aggregated in the decomposition / aggregation tank (1), the aggregate is collected in the filter (4), and the filter permeated water is pressurized by the high-pressure pump (5).
After removing the ionic and other impurity components through the reverse osmosis membrane (6), the purified water is taken out from the purified water outlet.

On the other hand, a part of the water in which the impurities are concentrated by the reverse osmosis membrane (6) is returned to the electrolysis coagulation tank. In the figure, an electrolysis coagulation tank (1) is a water tank in which positive and negative voltages from a DC power supply (16) are arranged on a plate-shaped aluminum or iron anode (2) and a cathode (3). When a voltage is applied to the DC power supply while water is introduced, aluminum or iron at the anode is eluted into the water to become aluminum hydroxide or iron hydroxide and, at the same time, aggregate fine particles and silicic acid.

[0027]

According to the method according to the first aspect of the present invention, particulate suspended matter and silicic acid components, which have conventionally caused clogging of reverse osmosis membranes or porous membranes, are used. Since it can be removed by aggregating in advance using an electrolytic aggregating tank, the life of the reverse osmosis membrane or the porous membrane can be significantly extended.

In order to remove particulate suspended matter and silicic acid components of the water to be treated, a coagulation precipitation method using aluminum sulfate or iron sulfate is also effective. This is not desirable because the burden on separation increases.

However, according to the electrolysis agglomeration method used in the present invention, there is no such increase of ions, and conversely, the load on membrane separation is reduced because the concentration of ions decreases.

According to the method of claim 2 of the present invention,
The service life of the ion exchange resin can be extended.

That is, in general, the ion exchange resin has a low ion exchange capacity of silicic acid. In particular, when pure water is produced using water having a high silicic acid concentration, the exchange or regeneration of the ion exchange resin can be performed in a relatively short period of time. Although it was necessary, the concentration of silicic acid in water can be reduced to 1/10 to 1/100 of ordinary natural water or tap water by using an electro-aggregation apparatus. The burden of the silicic acid component can be significantly reduced.

According to the method of the third aspect of the present invention, the efficiency of agglomeration of particulate suspended matter and silicic acid in the electrolytic flocculation tank can be increased. Generally, in the electrolysis coagulation method, the water to be treated is weakly acidic, and the coagulation effect is enhanced when the water is neutralized or basicized by electrolysis.

Therefore, a high coagulation effect can be obtained by weakly acidifying the water to be treated in advance by the diaphragm type electrolysis tank and supplying it to the electrolysis coagulation tank as in the present invention.

According to the method of the present invention, the water to be treated is weakly acidified in advance by a diaphragm type electrolysis tank and supplied to the electrolysis coagulation tank in the same manner as in the case of the third embodiment, whereby a high coagulation effect is obtained. Can be obtained.

Further, in this case, water in which ions which are not permeated through the reverse osmosis membrane or the porous membrane, that is, water having an increased electric conductivity is passed through the diaphragm type electrolysis tank. Efficiency is high, and the ion concentration of water in the electrolysis coagulation tank supplied with the acidic water produced in the diaphragm electrolysis tank is also increased, so that electrocoagulation with high electrical efficiency becomes possible.

According to the method of the present invention, by arranging a large number of intermediate electrodes (23) between a pair of anodes and cathodes, the electrodes sequentially transmit the intermediate electrodes, and each intermediate electrode performs electrolysis. Therefore, the same effect as when a large amount of current flows through a large number of cathodes and anodes can be obtained with a small amount of current, and the power supply can be made compact.

According to the method of claim 6 of the present invention, in the electrolytic coagulation tank, an electric current sequentially transfers an iron or aluminum filler having an insulating coating on a part of the surface filled between the anode and the cathode. As in the case of the fifth aspect, the same coagulation effect can be obtained with a small amount of current as in the case of using a large number of cathodes and anodes, and the power supply can be made compact.

According to the method of the present invention, in the electrolysis coagulation tank, electrolysis of iron and aluminum occurs simultaneously, and a substance which easily coagulates with iron and a substance which easily coagulates with aluminum simultaneously coagulate. , The aggregation effect can be enhanced. In particular, regarding the silicate component, it has been recognized that simultaneous electrolytic aggregation of iron and aluminum has a higher removal effect than that of a single case.

Each of the methods according to the eighth, ninth, tenth, and eleventh aspects of the present invention has the same effect as the above-described seventh aspect.

According to the method of the twelfth aspect of the present invention, the power supply for the electrolysis coagulation tank is not a DC power supply, but an alternating current power supply (3) in which the electrical polarity of the cathode and the anode is periodically inverted.
By using the method (7), even if iron or aluminum is used for any of the poles, it can be electrolyzed when it becomes an anode to produce an aggregation effect.

According to the method of the thirteenth aspect of the present invention, it is possible to efficiently produce a large number of small pieces of iron or aluminum partially insulative. In particular, even if such a material is filled, it is easy to maintain mutual insulation, and it is suitable as a filler for electrolytic aggregation.

According to the method of the present invention, in the case where a reverse osmosis membrane or a porous membrane is used, the particulate suspended matter and the silicic acid component, which have caused clogging of the membrane, are previously removed. The life of the reverse osmosis membrane or the porous membrane can be remarkably prolonged because it can be aggregated and removed by the decomposition / aggregation tank.

Further, by circulating the water enriched with ions that do not permeate those membranes to the electrolysis flocculation tank, the ion concentration of the water inside the electrolysis flocculation tank is increased, and the electric conductivity of the water is increased. And increase the energy efficiency of the electrolysis.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a method in which an electro-coagulation method according to claim 1 of the present invention is combined with a reverse osmosis membrane. (Example 1)

FIG. 2 is an explanatory view of a method in which an electrocoagulation method according to claim 2 of the present invention and an ion exchange resin are combined. (Example 2)

FIG. 3 is an explanatory view of a method in which a diaphragm type electrolysis method and an electrolysis aggregation method according to claim 3 of the present invention are combined.
(Example 3)

FIG. 4 shows a diaphragm electrolysis method according to claim 4 of the present invention;
It is explanatory drawing of the method which combined the electrolysis aggregation method and the reverse osmosis membrane. (Example 4)

FIG. 5 is an explanatory view of an electrolytic coagulation tank having an iron or aluminum intermediate electrode according to claim 5 of the present invention. (Example 5)

FIG. 6 is an explanatory view showing an electrolytic coagulation tank filled with a filler of iron or aluminum having a part of the surface insulated according to claim 6 of the present invention. (Example 6)

FIG. 7 is an explanatory view of an electrolytic coagulation tank having an intermediate electrode of iron and aluminum according to claim 7 of the present invention.
(Example 7)

FIG. 8 is an explanatory view showing an electrolytic flocculation tank filled with a filler of iron and aluminum, the surface of which is partially insulated according to claim 8 of the present invention. (Embodiment 8) It is an explanatory view of a method in which a diaphragm type electrolysis method and an electrolysis aggregation method according to claim 3 of the present invention are combined. (Example 3)

FIG. 9 is an explanatory view of an electrolytic coagulation tank having iron and aluminum anodes according to claim 9 of the present invention. (Example 9)

FIG. 10 is an explanatory view of an electrode of which surface is covered with a porous film according to claim 10 of the present invention and an electrolytic coagulation tank filled with a filler of iron and aluminum therebetween. (Example 10)

FIG. 11 is an explanatory view of a method for purifying water which sequentially passes through an electrolytic coagulation tank using iron and an electrolytic coagulation tank using aluminum according to claim 11 of the present invention. (Example 11)

FIG. 12 is an explanatory diagram of an electrolytic coagulation tank using an alternating current power supply according to claim 12 of the present invention. (Example 12)

FIG. 13 is an illustration of a method for producing a partially insulated iron and aluminum filling according to claim 13 of the present invention. (Example 13)

FIG. 14 is an explanatory view of a method in which the electro-coagulation method according to claim 14 of the present invention is combined with a reverse osmosis membrane. (Example 14)

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrolysis coagulation tank 2 Anode 3 Cathode 4 Filter 5 High-pressure pump 6 Reverse osmosis membrane tank 7 Reverse osmosis membrane 8 DC power supply 9 Inlet for water to be treated 10 Inlet for electrolysis coagulation tank 11 Purified water outlet 12 Outlet for concentrated impurity water Part 13 Impurity-concentrated water reflux section 14 Acidic water 15 Basic water 16 DC power supply 17 Diaphragm-type electrolysis tank 18 Porous membrane 19 Anode 20 Cathode 21 Ion exchange resin tank 22 Electrolytic coagulation tank outlet 23 Intermediate electrode 24 Iron or aluminum Filling of aluminum 25 Intermediate electrode of iron 26 Intermediate electrode of aluminum 27 Filling of iron 28 Filling of aluminum 29 Anode of iron 30 Anode of aluminum 31 Porous insulating film 32 Mixed filling of iron and aluminum 33 Anode of iron 34 Anode of aluminum 35 Plate of iron 36 Plate of aluminum 37 Alternating power Power supply 38 Top view of filled metal base material 39 Cross-sectional view of filled metal base material 40 Shredded portion of filled metal base material 41 Insulating coating 42 Filled material cut and manufactured 43 Conductive cross section

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) C02F 1/60 F term (Reference) 4D006 GA03 HA95 JA02Z JA53Z JA57Z KA01 KA12 KA41 KB01 KB11 KB13 KB14 MB02 PA01 PB02 PB08 PB23 PB27 PB28 PC80 4D025 AA01 AA09 AB01 AB17 BA07 DA05 DA06 4D038 AA01 AA08 AB57 BB08 BB09 BB10 BB16 BB17 BB18 4D061 DA01 DA08 DB07 DB08 DB11 DB15 DC06 DC18 EA03 EA07 EA07 EA09 EB04 EB05 EB18 EB18 EB05 EB05 EB05 FA16

Claims (14)

[Claims] An electrolytic flocculation tank (1) and a water tank (6) incorporating a reverse osmosis membrane or a porous membrane are used. The electrolytic flocculation tank (1) is made of an aluminum or iron anode (2) and a conductive material. A water tank in which a cathode of material (3) is arranged,
The water to be treated is introduced into the electrolysis coagulation tank (1), and positive and negative voltages are applied to the anode (2) and the cathode (3) to perform the electrolysis. Water that has flowed out of the electrolysis coagulation tank (1) is sent to a water tank (6) incorporating a reverse osmosis membrane or a porous membrane, and water permeating those membranes is taken out as purification water. Method. 2. An electrolytic flocculation tank (1), wherein the electrolytic flocculation tank (1) is a water tank in which an aluminum or iron anode (2) and a cathode (3) made of a conductive material are arranged. The exchange resin tank (21) is a vessel filled with an ion exchange resin, and introduces the water to be treated into the electrolysis flocculation tank (1) to aggregate fine particles and silicic acid components in the water to be treated.
A method for purifying water in which water flowing out of the electrolysis coagulation tank (1) is guided to an ion exchange resin tank (21) to remove ionic components and to purify the water. 3. A diaphragm type electrolysis tank (1) using a diaphragm type electrolysis tank (17), an electrolysis coagulation tank (1), a sedimentation filtration tank or a filter (4) for removing particulate suspended matter.
Reference numeral 7) denotes a water tank in which an anode (19) and a cathode (20) are arranged with a porous membrane (18) interposed therebetween, and the electrolytic coagulation tank (1) is made of an aluminum or iron anode (2) and a metal. The water to be treated is introduced into a diaphragm type electrolysis tank (17), and positive and negative voltages are applied to its anode and cathode by a DC power supply (16). The water to be treated is treated with acidic water (14) and basic water (1
5) and send the acidic water to the electrolysis coagulation tank (1),
Fine water and silicic acid components in the water to be treated are agglomerated, and basic water (15) is added to the water discharged from the electrolysis aggregating tank (1).
A method for purifying water, comprising the steps of: subjecting the aggregate to precipitation filtration or filtration by a filter (4) after adding the water. 4. Electrolysis using an electrolytic flocculation tank (1), a sedimentation filtration tank or filter (4), a water tank (6) incorporating a reverse osmosis membrane or a porous membrane, and a diaphragm type electrolysis tank (17). The coagulation tank (1) is a water tank in which an aluminum or iron anode (2) and a cathode (3) made of a conductive material are arranged, and the diaphragm type electrolysis tank (17) uses a porous membrane (18). A water tank in which an anode (19) and a cathode (20) are arranged, wherein water to be treated is introduced into an electrolysis flocculation tank (1), and fine particles and silicic acid components in the water to be treated are flocculated to form an aggregate. Is filtered by precipitation or filtered through a filter (4), the filtered water is collected by a filter (4), and the water permeated through the filter (4) is removed from a water tank (6) incorporating a reverse osmosis membrane or a porous membrane. To remove ionic and other impurity components and pass through the membrane. Water was removed as clean water, diaphragm type electrolytic cell the water that did not permeate the membrane (1
7) A method for purifying water, comprising separating basic water and acidic water into water, discarding the basic water, and circulating the acidic water to an electrolytic coagulation tank. 5. A method for purifying water according to claim 1, wherein the electrolytic coagulation tank is made of a plate-like or net-like conductive material. The anode and the cathode are placed parallel to each other, and between the anode and the cathode, there is no electrical connection between the anode and the cathode by a conductive material, and the plate or net is made of iron or aluminum. A method for purifying water using an electrolytic coagulation tank in which an electrode (23) is arranged in parallel with the anode and the cathode. 6. A method for purifying water according to any one of claims 1, 2, 3, 4, and 14, wherein the electrolysis coagulation tank has a plate-like, rod-like, cylindrical or net-like conductive property. An anode and a cathode made of a conductive material are placed, and between the anode and the cathode, a number of fixed or irregular materials such as iron or aluminum strips, spheres, crushed materials, compacts, etc. (24)
And a large number of these amorphous materials are individually covered with oxide, paint, insulating film, etc., and have electrically insulating parts. A method for purifying water using an electrolytic coagulation tank. 7. An anode and a cathode made of a plate-like or net-like conductive material are placed in parallel in a water tank, and the anode and the cathode are electrically connected to any of the anode and the cathode by the conductive material between the anode and the cathode. Water using an electrolytic coagulation tank having a structure in which an intermediate electrode including at least one iron plate (25) and at least one aluminum plate (26) is arranged in parallel with the anode and the cathode Cleaning method. 8. An anode and a cathode made of a plate-like, rod-like, cylindrical or net-like conductive material are placed, and a large number of metal strips, spheres, crushed materials, compacts, etc. are provided between the anode and the cathode. These are filled with fixed or irregular fillers, and many of these irregular materials are electrically insulative with their surfaces partially covered by oxides, paints, insulating coatings, etc. A method for purifying water using an electrolytic flocculation tank, characterized in that both of the fillers include iron (27) and aluminum (28). 9. A plurality of anodes and cathodes made of a plate-like or mesh-like conductive material are alternately placed in parallel in a water tank, at least one of which is made of iron (29) and at least one of which is made of iron (29). One is a method for purifying water using an electrolytic coagulation tank, wherein one is made of aluminum (30). 10. An anode and a cathode made of a plate-like, rod-like, cylindrical or net-like conductive material are placed, and the surfaces of the anode and the cathode face each other in a reticulated film, a porous film or the like. Film (3) made of insulating material and having holes through which current can pass
Numerous regular or irregular packings in the form of strips, spheres, crushed materials, compacts, etc., between the membranes covering the anodes and the cathodes coated in 1) (32) A method for purifying water, characterized by using an electrolytic flocculation tank having a structure in which the material is filled and the material of the filler contains both iron and aluminum. 11. The water to be treated is treated with a metal material (3) for coagulating iron.
3) A method for purifying water, comprising subjecting aluminum to a coagulation treatment using the electrolysis coagulation tank used as the metal material (34) for coagulation after the coagulation treatment using the electrolysis coagulation tank used as the method. 12. A method for purifying water according to any one of claims 1 to 11 and 14, wherein the power of the electrolytic coagulation tank is not a DC power supply, and the electrical polarity of the cathode and the anode is periodically changed. A method for purifying water, comprising using an inverting alternating current power supply (37). 13. A method for cleaning water according to claim 6, wherein the material between the anode and the cathode in the electrolysis coagulation tank is iron or aluminum. It is manufactured by oxidizing the outer surface of a cylindrical material, the outer surface of a rod-shaped material, or both surfaces of a plate-like material (38, 39) or coating the same with an insulating film (41) into small pieces. A method for purifying water, characterized by using a filled filling (42). 14. An electrolytic flocculation tank (1), a sedimentation filtration tank or filter (4) for removing particulate suspended matter,
A water pump (5) and a water tank (6) incorporating a reverse osmosis membrane or a porous membrane are used, and the electrolytic coagulation tank (1) is made of an aluminum or iron anode (2) and a conductive material cathode (3). The water to be treated is introduced into the disposed water tank, and the positive and negative voltages are applied to the anode (2) and the cathode (3) from the DC power supply (16) to perform the electrolysis. By performing the above, the fine particles and the silicic acid component in the water to be treated are agglomerated, the agglomerated matter is precipitated and filtered, or filtered by a filter (4), and the filtered water is pressurized by a water pump (5) to form a reverse osmosis membrane or It is sent to a water tank (6) incorporating a porous membrane, and water permeating the membrane is taken out as cleaning water, and a portion of water not permeating the membrane is refluxed to the electro-aggregation apparatus (1). Water purification method.