JP2002254081A - Waste water treatment equipment and waste water treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide waste water treatment equipment that can treat nitrogen compounds and phosphorus compounds in the same treatment vessel and also can treat untreated water containing nitrogen compounds and phosphorus compounds effectively. SOLUTION: This electrochemical waste water treatment equipment 1 for untreated water containing nitrogen compounds and phosphorus compounds is equipped with a treatment vessel 2 to receive untreated water, a cathode 6 which is composed of electric conductor and at least a part of which is immersed in the untreated water, an anode 5 which is composed of an insoluble metal or carbon and at least a part of which is immersed in the untreated water and an iron bar 15 which is installed keeping a way to the anode 5 and the cathode 6 and which is immersed in untreated water in the treatment vessel 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wastewater treatment apparatus containing phosphoric acid, phosphorus compounds, phosphate ions, organic nitrogen, nitrite nitrogen, nitrate nitrogen, and ammonia nitrogen.

[0002]

2. Description of the Related Art Conventionally, one of the causes of eutrophication of rivers and lakes.
It is well known that there are nitrogen compounds and phosphorus compounds. Further, these phosphorus compounds and nitrogen compounds are abundant in domestic household wastewater and industrial wastewater, but are difficult to purify, and no effective measures can be taken at present. Generally, biological treatment is performed to treat nitrogen compounds. First, a nitrification step of converting ammonia nitrogen to nitrate nitrogen and a denitrification step of converting nitrate nitrogen to nitrogen gas are performed. Is being done.

On the other hand, as a method of treating a phosphorus compound, an iron electrolytic elution method is known. This technology is a technology in which iron ions generated by iron electrolysis and phosphate ions are reacted in water to be treated, and precipitated and removed as water-insoluble iron phosphate.

[0004]

However, in conventional biological treatment apparatuses for nitrogen compounds and phosphorus compounds in biological treatment, two reaction tanks are required and the processing time is slow, so that the processing efficiency is reduced. there were. Further, in the conventional method, since the water to be treated containing the nitrogen compound and the phosphorus compound is not simultaneously treated, there is a problem that the apparatus becomes large.

[0005] In the biological treatment, large-capacity aerobic tanks and anaerobic tanks are required to hold nitrifying bacteria and denitrifying bacteria, which causes a rise in equipment construction costs and an increase in equipment installation area. was there. Furthermore, since the denitrifying bacteria are significantly affected by the surrounding temperature environment and other components contained in the water to be treated, the activity is reduced particularly in winter when the temperature is lowered, and the denitrifying action is reduced. There has been a problem that the processing efficiency is reduced and the processing efficiency becomes unstable.

Further, when the treatment of a nitrogen compound by electrolysis and the treatment of a phosphorus compound by iron electrolysis are performed simultaneously in the same treatment tank, the conditions of the voltage and current applied to the electrodes in both treatments are different. When iron treatment of a phosphorus compound is performed in accordance with the electrolysis treatment described above, iron elution remarkably occurs. Therefore, it is difficult to treat nitrogen compounds and phosphorus compounds in the same treatment tank.

Accordingly, the present invention has been made in order to solve the conventional technical problems, and performs the treatment of a nitrogen compound and a phosphorus compound in the same treatment tank and efficiently removes the nitrogen compound and the phosphorus compound. It is an object of the present invention to provide a wastewater treatment device capable of performing treatment of the water to be treated.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a wastewater treatment apparatus for treating nitrogen compounds and phosphorus compounds in water to be treated by an electrochemical method. At least a part is immersed,
A cathode composed of a conductive material, at least a part of which is immersed in the water to be treated, and an anode composed of a conductive insoluble material or carbon, and is immersed in the water to be treated in a treatment tank. An iron material is provided at a position separated from the anode and the cathode.

According to the present invention, in a wastewater treatment apparatus for treating a nitrogen compound and a phosphorus compound in water to be treated by an electrochemical method, a treatment tank for receiving the water to be treated, and at least a part of the water being treated. A cathode immersed and made of a conductive material, an anode immersed at least in part in water to be treated and made of a conductive insoluble material or carbon, Since the iron material is provided in a position separated from the anode and the cathode by being immersed in the treatment water, the electric potential applied to the iron material becomes moderate, thereby suppressing an excessive amount of iron elution, and performing the same treatment. In the tank, the nitrogen compound and the phosphorus compound can be simultaneously treated.

[0010] This makes it possible to efficiently remove nitrogen compounds and phosphorus compounds from the water to be treated containing nitrogen compounds and phosphorus compounds discharged from general households and factories, thereby improving the wastewater treatment capacity. You.

Further, it is possible to perform the treatment of the phosphorus compound and the nitrogen compound in the same tank without providing a specially separate processing tank, and it is possible to reduce the size of the processing apparatus for realizing the present invention. become able to.

According to a second aspect of the present invention, in addition to the first aspect, the metal material forming the cathode may be a conductor containing Group Ib or Group IIb of the periodic table or a homologous conductor. It is characterized by using a material covered with a conductor.

According to the invention of claim 2, in addition to the invention of claim 1, the metal material forming the cathode is a conductor containing Group Ib or Group IIb of the periodic table or a conductor containing the same group. The use of a material coated on the substrate enables the reduction reaction of nitrate nitrogen and nitrite nitrogen in the water to be treated to ammonia nitrogen to be further promoted, and the time required for the reduction reaction to be further reduced. become.

A third aspect of the present invention is directed to the wastewater treatment apparatus according to the first or second aspect, wherein the iron material is located on the cathode side of the anode and on the anode side of the cathode.

According to the third aspect of the present invention, in addition to the first or second aspect, since the iron material is located on the cathode side of the anode and on the anode side of the cathode, the potential applied to the iron material is Is further moderate, whereby the amount of excessive iron elution can be suppressed, and the nitrogen compound and the phosphorus compound can be simultaneously treated in the same treatment tank.

According to a fourth aspect of the present invention, in addition to the first, second, or third aspect of the present invention, the wastewater treatment apparatus further comprises:
It is characterized by being located outside a line connecting the edge of the anode and the edge of the cathode.

According to the fourth aspect of the present invention, in addition to the first, second or third aspect of the present invention, the iron material is provided outside the line connecting the edge of the anode and the edge of the cathode. Since it is located, the potential applied to the iron material from the anode and the cathode can be appropriately suppressed, so that the iron elution amount of the iron material can be further appropriately suppressed. The compound and the phosphorus compound can be treated simultaneously.

According to a fifth aspect of the present invention, in addition to the first, second, third, or fourth aspect of the present invention, the iron material is fixed to the treatment tank by an installation position adjusting means and installed. The position adjusting means is characterized in that the distance between the anode and the cathode can be changed by arbitrarily moving the iron material.

According to the fifth aspect of the present invention, in addition to the first, second, third or fourth aspect of the present invention, the iron material further comprises:
While being fixed to the processing tank by the setting value adjusting means, the setting position adjusting means, by arbitrarily moving the iron material,
Because it is possible to change the interval between the anode or cathode,
By operating the installation position adjusting means, the distance between the iron material and the anode or the cathode can be changed according to the amount of the phosphorus compound present in the water to be treated.

Therefore, when the amount of the phosphorus compound present in the water to be treated is small, the distance between the anode or the cathode and the iron material is widened to significantly suppress the amount of iron eluted from the iron material, and Can be prevented from being eluted. In addition, when the amount of the phosphorus compound present in the water to be treated is large, the distance between the anode or the cathode and the iron material is narrowed to increase the amount of iron eluted from the iron material and increase the amount of the phosphorus compound in the water to be treated. The amount of iron required for the treatment of iron can be eluted.

According to a sixth aspect of the present invention, in addition to the first, second, third, fourth, or fifth aspect of the present invention, the water to be treated is treated by a biological treatment septic tank. It is characterized by being water after having been done.

According to the sixth aspect of the present invention, in addition to the first, second, third, fourth or fifth aspect of the present invention, the water to be treated is treated with a biological treatment septic tank. Because it is water, biological treatment septic tanks, such as activated sludge treatment tanks, while removing COD and BOD highly,
Bacteria generated in the activated sludge treatment tank are sterilized by hypochlorous acid or active oxygen, and can be subjected to wastewater treatment.

A wastewater treatment system according to a seventh aspect of the present invention is characterized in that the wastewater treatment apparatus according to any one of the first, second, third, fourth, and fifth aspects is disposed downstream of the biological treatment septic tank. And

According to the wastewater treatment system of the seventh aspect of the present invention, the wastewater treatment apparatus according to the first, second, third, fourth, or fifth aspect is disposed downstream of the biological treatment / purification tank. In addition to removing COD and BOD to a high degree in a biological treatment septic tank, for example, an activated sludge treatment tank, etc., sterilizing bacteria generated in the activated sludge treatment tank with hypochlorous acid or active oxygen, and then performing wastewater treatment. Will be able to

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing an outline of a wastewater treatment apparatus 1 for realizing the nitrogen and phosphorus treatment method of the present invention. The wastewater treatment apparatus 1 according to the present embodiment has a treatment tank 2 that constitutes a treatment chamber 4 having an inlet and an outlet for wastewater (not shown), and at least a part of the treatment tank 2 is immersed in the water to be treated in the treatment chamber 4. A pair of electrodes, ie, an anode 5, a cathode 6, and the electrodes 5, 6
And a control device (not shown) for controlling the electrodes 7. In addition, 1 in the figure
Reference numeral 0 denotes a stirrer as stirring means for stirring the inside of the processing tank 2.

The cathode 6 is made of a conductor containing Group Ib or Group IIb of the periodic table, or a material obtained by coating the same with a conductor.
It is composed of an insoluble electrode containing an insoluble metal, for example, platinum, iridium, palladium or an oxide thereof, or carbon.

Further, a shielding member 9 formed in a cylindrical shape as shown in FIG. 2 is provided between the anode 5 and the cathode 6 so as to surround the anode 5.
The shielding member 9 is made of, for example, a non-conductive member such as a glass fiber or a plastic mesh, whereby oxygen bubbles generated from the anode 5 are removed from the cathode 6.
To the side. At this time,
Ions existing on the anode 5 side can pass through the shielding member 9 and move to the cathode 6 side.

Further, in the processing tank 2, an iron bar 15 formed, for example, in a bar shape as an iron material is provided. The iron bar 15 is fixed by a suspension member 16 as an installation position adjusting means so as to be parallel to the cathode and the anode. At this time, the iron bar 15 is located on the cathode 6 side of the anode 5, at a position corresponding to the anode 5 side of the cathode 6, and at the edge of the anode, for example, the lower end of the anode, the edge of the cathode, For example, it is provided so as to be located outside a line connecting the lower ends of the cathodes, in this embodiment, below the line.

The position of the iron bar 15 is
6, the anode 5 and the lower end of the cathode 6 (position A in FIG. 3) as shown in FIG.
And a position at a predetermined distance from the lower end of the cathode 6 (FIG. 3)
, The position can be arbitrarily moved up to the position B).
In this embodiment, the suspension member 1 is used as an installation position adjusting means.
6, the holding member for fixing both ends of the iron bar 15 to the inner wall of the processing tank 2 may be used. Also,
In the present embodiment, the iron material is constituted by the rod-shaped iron bar 15, but it is also possible to adopt another form.

With the above configuration, the processing chamber 4 in the processing tank 2
To store treated water containing nitrate nitrogen and phosphorus compounds
The power supply 7 is turned on by the control device, and the cathode 6 and the anode 5 are energized. Thus, on the cathode 6 side, nitrate ions contained in the water to be treated are converted into nitrite ions by a reduction reaction (reaction A). Further, the nitrite ions generated by the reduction reaction of the nitrate ions are further converted to ammonia by the reduction reaction (reaction B). The reaction A and the reaction B are shown below. Reaction ^{_{A NO 3 - + H 2 O}} + 2e - → NO 2 - + 2OH - reaction ^{_{B NO 2 - + 5H 2 O}} + 6e - → NH 3 (aq) +7
OH ^-

On the other hand, on the anode 5 side, active oxygen and hypochlorous acid are generated from the surface of the anode 5, whereby nitrogen gas is generated by denitrification of ammonia in the water to be treated (reaction C). The reaction C is shown below. Reaction C NH ₃ (aq) +3 (O) → N ₂ ↑ + 3H ₂ O

Thus, nitrogen compounds such as nitrate nitrogen, nitrite nitrogen and ammonia nitrogen in the water to be treated can be effectively treated. In particular, in this embodiment, the cathode 6 is made of a conductor containing Group Ib or Group IIb of the periodic table or a conductor coated with the same group, for example, brass which is an alloy of copper and zinc. The reduction reaction of nitrate nitrogen and nitrite nitrogen in the treated water to ammonia can be further promoted, and the time required for the reduction reaction can be further reduced.

The iron rods 15 in the water to be treated generate iron ions due to the potential applied to the anode 5 and the cathode 6. The iron ions coagulate and precipitate with the phosphate ions in the water to be treated by the dephosphorization reaction, thereby producing water-insoluble iron phosphate (reaction D). The reaction D is shown below. Reaction D Fe ³⁺ + PO ₄ ^3- → FePO ₄

At this time, the position of the iron bar 15 is moved by the suspension member 16 in accordance with the amount of the phosphorus compound contained in the water to be treated. That is, when the amount of the phosphorus compound contained in the for-treatment water is large, the water is moved to the position A in order to increase the amount of iron eluted from the iron bar 15. As a result, the iron bar 15 is relatively close to the anode 5 and the cathode 6, so that the amount of iron eluted from the iron bar 15 is suppressed to a certain amount, and coagulation and precipitation occur with phosphate ions in the water to be treated.

When the amount of the phosphorus compound contained in the water to be treated is small, the water is moved to the position B in order to suppress the elution amount of iron from the iron bar 15. This allows
Since the iron bar 15 has a certain distance or more from the anode 5 and the cathode 6, the amount of iron elution from the iron bar 15 is suppressed, and it is possible to avoid excessive iron elution.

In the present embodiment, the position of the iron bar 15 is limited.
Even if the iron bar 15 is installed at a position other than the above and not in contact with the anode 5 and the cathode 6, the phosphorus compound in the water to be treated can be removed. Further, as compared with the case where the iron bar 15 is installed in contact with the anode 5 and the cathode 6, an appropriate electric potential can be applied to the iron bar 15 and the amount of iron elution can be suppressed. And the like, maintenance workability can be reduced, and unnecessary elution of iron can be reduced.

By changing the position of the iron bar 15, the potential applied to the iron bar 15 can be adjusted, and the amount of iron eluted from the iron bar 15 can be adjusted. Therefore, the amount of iron elution can be changed in accordance with the amount of the phosphorus compound contained in the water to be treated, so that excessive iron elution can be avoided.

On the other hand, the experimental results shown in FIG. 4 show that each of the ions 5 with the passage of time in the case where the platinum 5 and iridium-based electrodes were used for the anode 5 and the cathode 6 and the water to be treated as general domestic wastewater was electrolyzed. Shows the change in density.

According to FIG. 4, glutamic acid, which is a nitrogen compound contained in the water to be treated, is gradually changed to ammonium ion by electrolysis, and thus decreases with the passage of time. After the passage, there is almost no presence in the water to be treated. On the other hand, the nitrate ion once increases due to the oxidation of the nitrite ion in the water to be treated, and then gradually changes to ammonia ion at the cathode 6, so that it decreases with the passage of time and the electrolysis starts. After a lapse of 150 minutes from the treatment, almost no water is present in the water to be treated. Further, after the ammonia ion generated in the cathode 6 gradually increases, after a certain time has passed,
It gradually decreases and almost does not exist in the water to be treated 150 minutes after the start of electrolysis.

In the vicinity of the anode 5, the phosphate ions in the water to be treated cause a dephosphorization reaction with the iron ions due to the elution of iron from the iron material 15 affected by the potentials of the anode 5 and the cathode 6. A precipitate is formed on the bottom surface of the tank 2 in the state of iron phosphate. Therefore, the phosphate ions gradually decrease with the passage of time, and almost no phosphate ions are present in the water to be treated after 170 minutes from the start of electrolysis.

Thus, the iron material 15 provided at a position separated from the anode 5 and the cathode as described above allows
Iron ions required for removing phosphate ions in the water to be treated can be supplied, and the phosphorus compound in the water to be treated can be efficiently treated.

At this time, since the iron material 15 is provided at a position separated from the anode 5 and the cathode 6, the electric potential applied to the iron material 15 is moderate.
Thereby, an excessive amount of iron elution can be suppressed, and the nitrogen compound and the phosphorus compound can be simultaneously treated in the same treatment tank 2.

Therefore, the nitrogen compound and the phosphorus compound can be efficiently removed from the treated water containing the nitrogen compound and the phosphorus compound discharged from general households, factories, etc., and the wastewater treatment capacity is improved. .

Further, it is possible to perform the treatment of the phosphorus compound and the nitrogen compound in the same tank without providing a specially separate processing tank, so that the processing apparatus can be downsized.

Further, since the iron material 15 is located on the cathode 6 side of the anode 5 and on the anode 5 side of the cathode 6, the electric potential applied to the iron material 15 becomes more appropriate. Thereby, an excessive amount of iron elution can be suppressed. Further, in the present embodiment, the iron material 15 is further installed at a position outside the line connecting the edge of the anode 5 and the edge of the cathode 6, so that the iron material 15 is further increased. Of the iron can be appropriately suppressed.

As a first concrete application example of the present invention, as shown in FIG. 5, the water to be treated is stored in a biological treatment septic tank, in this embodiment, a so-called activated sludge treatment tank 11, and the activated sludge treatment is carried out. After removing COD and BOD in the tank 11, the CO
The treated water subjected to the D and BOD treatment is treated with a nitrogen compound and a phosphorus compound in the treatment tank 2 of the wastewater treatment apparatus 1 to which the present invention is applied.

Thus, the water to be treated is supplied to the activated sludge treatment tank 1
After once treating COD and BOD in step 1, the wastewater treatment apparatus 1 can further treat nitrogen compounds and phosphorus compounds, so that the water to be treated can be treated effectively. become. The activated sludge treatment tank 11
The water to be treated, which is treated in the wastewater treatment apparatus 11, contains bacteria generated in the activated sludge treatment tank 11, but is sterilized by the hypochlorous acid or active oxygen in the wastewater treatment apparatus 1 as described above. The treated water can be drained in a state suitable for the environment.

Further, as a second specific application example of the present invention, as shown in FIG. 6, suspended substances in the water to be treated can be removed by so-called electrolytic levitation.

Further, as a third specific application example of the present invention, as shown in FIG. 7, it can be used for removing nitrogen compounds and phosphorus compounds in water in a water tank 12 for inhabiting fish in a fish cage or an aquarium. it can. The water in which a fish inhabits is remarkably contaminated by nitrogen compounds such as ammonia discharged from the fish, so that it is necessary to periodically replace the water in the water tank. Therefore, the water tank 1 containing a nitrogen compound
The water in 2 is treated with a nitrogen compound by the wastewater treatment device 1, and then the treated water discharged from the wastewater treatment device 1 is treated with hypochlorous acid in the treated water by the hypochlorous acid removing device 13. Is removed and returned into the water tank 12.

Accordingly, it is not necessary to periodically change the water in the water tank 12, and the maintenance workability of the water tank 12 can be improved. In addition, since the water to be treated stored in the wastewater treatment device 1 from the water tank 12 is sterilized by hypochlorous acid, the water to be treated is returned to the water tank 12 and the survival rate of the fish in the water tank 12 is returned. Can be improved.

In addition, the wastewater treatment method to which the present invention is applied can be applied to purification of water to be treated in pools and baths, purification of well water and groundwater, and the like.

[0052]

As described above in detail, according to the present invention, in a wastewater treatment apparatus for treating nitrogen compounds and phosphorus compounds in water to be treated by an electrochemical method, a treatment tank for receiving the water to be treated, While at least a part is immersed in the treated water, a cathode composed of a conductive material, and at least a part immersed in the water to be treated, and an anode composed of a conductive insoluble material or carbon Since the iron material is immersed in the water to be treated in the treatment tank and separated from the anode and the cathode, the potential applied to the iron material becomes appropriate, thereby suppressing the excessive elution of iron. And the nitrogen compound and the phosphorus compound can be simultaneously treated in the same treatment tank.

As a result, it is possible to efficiently remove nitrogen compounds and phosphorus compounds from the water to be treated containing nitrogen compounds and phosphorus compounds discharged from general households and factories, etc., thereby improving the wastewater treatment capacity. You.

Further, it is possible to perform the treatment of the phosphorus compound and the nitrogen compound in the same tank without providing a specially separate processing tank, so that the processing apparatus for realizing the present invention can be downsized. become able to.

According to the invention of claim 2, in addition to the invention of claim 1, the metal material forming the cathode is a conductor containing Group Ib or Group IIb of the periodic table, or a conductor containing the same group. Is used, the reduction reaction of nitrate nitrogen and nitrite nitrogen in the water to be treated to ammonia can be further promoted, and the time required for the reduction reaction can be further reduced. .

According to the third aspect of the present invention, in addition to the first or second aspect, the iron material is located on the cathode side of the anode and on the anode side of the cathode. Is further moderate, whereby the amount of excessive iron elution can be suppressed, and the nitrogen compound and the phosphorus compound can be simultaneously treated in the same treatment tank.

According to the fourth aspect of the present invention, in addition to the first, second or third aspect of the present invention, the iron material is provided outside the line connecting the edge of the anode and the edge of the cathode. Since it is located, the potential applied to the iron material from the anode and the cathode can be appropriately suppressed, so that the iron elution amount of the iron material can be further appropriately suppressed. The compound and the phosphorus compound can be treated simultaneously.

According to the fifth aspect of the present invention, in addition to the first, second, third or fourth aspect of the present invention, the iron material further comprises:
While being fixed to the processing tank by the setting value adjusting means, the setting position adjusting means, by arbitrarily moving the iron material,
Because it is possible to change the interval between the anode or cathode,
By operating the installation position adjusting means, the distance between the iron material and the anode or the cathode can be changed according to the amount of the phosphorus compound present in the water to be treated.

Therefore, when the amount of the phosphorus compound present in the water to be treated is small, by increasing the distance between the anode or cathode and the iron material, the amount of iron eluted from the iron material is remarkably suppressed, and more than necessary. Can be prevented from being eluted. In addition, when the amount of the phosphorus compound present in the water to be treated is large, the distance between the anode or the cathode and the iron material is narrowed to increase the amount of iron eluted from the iron material and increase the amount of the phosphorus compound in the water to be treated. The amount of iron required for the treatment of iron can be eluted.

According to the sixth aspect of the present invention, in addition to the first, second, third, fourth or fifth aspect of the present invention, the water to be treated is treated with a biological treatment septic tank. Because it is water, biological treatment septic tanks, such as activated sludge treatment tanks, while removing COD and BOD highly,
Bacteria generated in the activated sludge treatment tank are sterilized by hypochlorous acid or active oxygen, and can be subjected to wastewater treatment.

According to the wastewater treatment system according to the seventh aspect of the present invention, the wastewater treatment apparatus according to the first, second, third, fourth or fifth aspect is disposed downstream of the biological treatment and purification tank. In addition to removing COD and BOD to a high degree in a biological treatment septic tank, for example, an activated sludge treatment tank, etc., sterilizing bacteria generated in the activated sludge treatment tank with hypochlorous acid or active oxygen, and then performing wastewater treatment. Will be able to

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an outline of a wastewater treatment device of the present invention.

FIG. 2 is a diagram illustrating the structure of an anode.

FIG. 3 is a diagram showing a configuration inside a processing tank.

FIG. 4 is a diagram showing a change in each ion concentration.

FIG. 5 is a diagram illustrating a first specific application example of the present invention.

FIG. 6 is a diagram illustrating a second specific application example of the present invention.

FIG. 7 is a diagram illustrating a third specific application example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wastewater treatment apparatus 2 Treatment tank 4 Wastewater treatment chamber 5 Anode 6 Cathode 7 Power supply 9 Shielding member 10 Stirrer 11 Activated sludge treatment tank 12 Water tank 13 Hypochlorous acid removing device 15 Iron rod 16 Hanging member

Continued on the front page F term (reference) 4D028 AA00 4D038 AA05 AA08 AB46 BA02 BB10 BB12 BB19 4D061 DA02 DA06 DA07 DA08 DB15 DB19 DC14 DC15 EA02 EA03 EA04 EA08 EB04 EB12 EB19 EB29 EB31 FA10 FA15

Claims (7)

[Claims] 1. A wastewater treatment apparatus for treating a nitrogen compound and a phosphorus compound in water to be treated by an electrochemical method, comprising: a treatment tank receiving the water to be treated; and at least a part immersed in the water to be treated. And a cathode composed of a conductive material, an anode composed of a conductive insoluble material or carbon and at least partially immersed in the water to be treated, and A wastewater treatment apparatus, wherein the wastewater treatment apparatus is provided with an iron material immersed in the to-be-treated water and separated from the anode and the cathode. 2. The conductive material forming the cathode,
2. The wastewater treatment apparatus according to claim 1, wherein a conductor containing Group Ib or Group IIb of the periodic table or a conductor coated with the same group is used. 3. The wastewater treatment apparatus according to claim 1, wherein the iron material is located on the cathode side of the anode and on the anode side of the cathode. 4. The wastewater treatment apparatus according to claim 3, wherein the iron material is located outside a line connecting the edge of the anode and the edge of the cathode. 5. The iron material is fixed to the processing tank by an installation position adjustment means, and the installation position adjustment means arbitrarily moves the iron material, thereby allowing the iron material and the anode or 5. The wastewater treatment apparatus according to claim 1, wherein the distance between the cathode and the cathode can be changed. 6. The wastewater treatment according to claim 1, wherein the water to be treated is water treated by a biological treatment septic tank. apparatus. 7. A wastewater treatment system, wherein the wastewater treatment apparatus according to claim 1, 2, 3, 4, or 5 is disposed at a stage subsequent to the biological treatment septic tank.