JP5194151B2 - Waste water treatment equipment - Google Patents

Description

  The present invention relates to a wastewater treatment apparatus, and more particularly, to a wastewater treatment apparatus that performs removal treatment of ammonia nitrogen contained in wastewater at a high concentration by partial nitritation and anaerobic ammonia oxidation.

  In the water treatment technology, a circulation nitrification denitrification method has been widely known as a nitrogen removal technology in ammonia-containing wastewater. However, this technology requires a large installation area and is expensive in terms of equipment, such as the installation of a circulation pump, and it is necessary to perform aeration excessively in order to nitrify the entire amount of ammonia. There is also a problem in terms of running costs, such as the need to add a hydrogen donor as a nutrient source.

  However, in recent years, in the treatment method of organic waste liquid containing ammonia nitrogen, ammonia nitrogen in the waste liquid is partially nitrified by nitrifying bacteria, and the resulting nitrite is obtained by anaerobic ammonia oxidation method. A treatment method for denitrification is known.

  This technology not only reduces the amount of aeration required for nitrification due to partial oxidation from ammonia to nitrous acid during the nitrification reaction. In addition, the microorganism involved in this reaction is a self-trophic bacterium. There is an advantage that the addition of an organic substance such as methanol is not required, which leads to a reduction in chemical cost, and the amount of generated sludge is greatly reduced as compared with the prior art (see, for example, Patent Document 1).

  Furthermore, as a technique using this anaerobic ammonia oxidation method, a SNAP method and a Canon method have been proposed. The SNAP method is a method for removing ammonia in a single tank, generating convection in the tank by aeration from the center of the bottom of the tank, and attaching ammonia-oxidizing bacteria, which are aerobic microorganisms, to the surface of the attached fixed carrier installed in the periphery of the tank. In addition, anaerobic ammonia-oxidizing bacteria are allowed to inhabit anaerobic parts inside the carrier, and nitrification and denitrification are performed by the action of both. On the other hand, the Canon method is a method in which half of the ammonia in the inflowing water is converted to nitric acid by the action of ammonia-oxidizing bacteria by supplying oxygen limitedly to the reactor, and nitrogen is removed in one tank.

  However, both of these methods have low DO in the reactor and give priority to anaerobic ammonia-oxidizing bacteria, so there is a problem that the nitrite production rate is low and the denitrification rate is also reduced. . In addition, it is effective for wastewater with a low C / N ratio, but it is difficult to apply to wastewater with high BOD.

JP 2005-74253 A

  As described above, the denitrification treatment in one tank has various problems as in the SNAP method and the Canon method, but the method described in Patent Document 1 has the above-described advantages. However, it is necessary to install a plurality of treatment tanks, and there are problems in terms of equipment cost, as well as problems such as bringing in BOD and DO, and fine adjustment of the nitrous acid / ammonia concentration ratio.

  Therefore, the present invention provides a wastewater treatment apparatus that can efficiently perform nitritation anaerobic denitrification treatment with a simple apparatus configuration even with high BOD wastewater, and can be applied to both a continuous type and a batch type. The purpose is that.

In order to achieve the above object, a wastewater treatment apparatus of the present invention is a wastewater treatment apparatus for removing ammonia from wastewater having an ammoniacal nitrogen concentration of 500 ppm or more, and aeration-treats the wastewater introduced from the wastewater introduction means. An aerobic treatment unit that oxidizes ammonium ions in wastewater to nitrite ions; an anaerobic treatment unit that reacts the generated nitrite ions and ammonium ions in wastewater in an anaerobic state to generate nitrogen gas; and wherein the processing unit is partitioned between anaerobic treatment section and a suppressing partition member the flow of water Rutotomoni, the aerobic treatment section, have a means for deriving the means and process water introducing wastewater and the partition member, together with the ammonium ions and nitrite ions have an ion transmission unit can pass by diffusion phenomena, inhibiting water flow resistance distribution of the water Is characterized by passing water at a pressure 10kPa is 500L / min / ^{m 2} or less.

Also, if BOD concentration before Symbol wastewater is more than 500 ppm, batch-type waste water treatment apparatus is preferred. The partition member can be formed of a metal water-permeable plate material. The ion permeable portion is one of a sponge-type molded body, a filter cloth, a punching plate, or a combination thereof.

  According to the wastewater treatment apparatus of the present invention, since convection (circulation) of water (liquid) between the aerobic treatment unit and the anaerobic treatment unit can be suppressed to the minimum necessary, BOD, DO to the anaerobic treatment unit This makes it possible to operate with high efficiency and high load, and to reliably treat wastewater with an ammoniacal nitrogen concentration of 500 ppm or more.

It is a schematic systematic diagram showing a reference example of the present invention. It is a general | schematic systematic diagram which shows the example of 1 form which applied this invention to the batch type wastewater treatment apparatus. It is a perspective view of the principal part which shows the outline of a partition member. It is sectional drawing of the principal part which shows an example of the partition member which has arrange | positioned the several baffle plate which has a through-hole. It is each front view which shows the example of various shapes of a partition member. It is each cross-sectional side view which shows the various shape examples of a partition member. It is each cross-sectional side view which shows the various arrangement | positioning examples when a plurality of partition members are provided. It is a schematic system diagram which shows the other example of a wastewater treatment apparatus of this invention.

FIG. 1 is a schematic system diagram showing a reference example of the present invention. This continuous wastewater treatment apparatus is configured such that the inside of a treatment tank 11 is partitioned into an aerobic treatment unit 13 and an anaerobic treatment unit 14 by a partition member 12. A diffuser 15 is provided for supplying the air.

  The aerobic treatment unit 13 is prevented from being inclined to acidity by waste water introduction means 16 for continuously introducing a predetermined amount of waste water and nitrate nitrogen (nitrite ions) generated in the aerobic treatment unit 13. Alkaline agent addition means 17 for adding an alkali agent for maintaining an appropriate pH, and a pH meter 18 for measuring the pH in the aerobic treatment unit 13 and adjusting the addition amount of the alkali agent are provided, The anaerobic treatment unit 14 is provided with treated water deriving means 19.

  In this continuous wastewater treatment apparatus, the wastewater continuously introduced from the wastewater introduction means 16 is subjected to an ammonia removal treatment by an aerobic treatment in the aerobic treatment unit 13 and an anaerobic treatment in the anaerobic treatment unit 14. The treated water having a reduced ammonia nitrogen concentration is continuously withdrawn from the treated water deriving means 19 of the anaerobic treatment unit 14, whereby the waste water treatment is continuously performed. At this time, when the BOD concentration in the wastewater is less than 500 ppm, the amount of sludge generated in the aerobic treatment unit 13 is small, and even if the sludge flows into the anaerobic treatment unit 14, the influence on the anaerobic ammonia oxidizing bacteria is small. The use of such a continuous wastewater treatment apparatus is suitable, and wastewater treatment can be performed continuously and efficiently.

  FIG. 2 is a schematic system diagram showing an embodiment in which the present invention is applied to a batch type (batch type) wastewater treatment apparatus. In the batch type (batch type) wastewater treatment apparatus, the aerobic treatment unit 13 includes both a wastewater introduction unit 16 for introducing wastewater and a treated water deriving unit 19 for deriving treated water. Since it is different from the continuous wastewater treatment apparatus and the other points are common, the same components as those shown in the embodiment of FIG. Description is omitted.

  In this batch-type wastewater treatment apparatus, a predetermined amount of wastewater is introduced into the treatment tank 11 from the wastewater introduction means 16 via the aerobic treatment unit 13, and the aerobic treatment in the aerobic treatment unit 13 and the anaerobic treatment unit 14 are performed. The anaerobic treatment is performed for a predetermined period of time to remove the ammonia, and then the treated water with a reduced ammoniacal nitrogen concentration is extracted from the treated water deriving means 19 of the aerobic treatment unit 13 to perform one wastewater treatment. Done. This batch type wastewater treatment apparatus is suitable when the BOD concentration in the wastewater is 500 ppm or more. That is, when the BOD concentration is 500 ppm or more, the amount of sludge generated in the aerobic treatment unit 12 increases, and if a large amount of sludge flows into the anaerobic treatment unit 14, there is a possibility of inhibiting the activity of anaerobic ammonia oxidizing bacteria. Therefore, it is necessary to discharge the generated sludge together with the treated water from the aerobic treatment unit 13.

  FIG. 3 is a perspective view of an essential part showing an outline of a partition member 12 that partitions the inside of the treatment tank 11 into an aerobic treatment unit 13 and an anaerobic treatment unit 14 in the continuous wastewater treatment apparatus and the batch type wastewater treatment apparatus. In this partition member 12, 70% or more of the area in water is used as the ion permeable part 21 and the remaining area as the water passing part 22. The water flow portion 22 is an opening that allows water between the aerobic treatment portion 13 and the anaerobic treatment portion 14 to pass therethrough, and by providing such a water flow portion 22 in a part of the partition member 12. Since the water that moves from the aerobic processing unit 13 to the anaerobic processing unit 14 does not pass through the partition member 12, the adhesion of sludge to the partition member 12 can be reduced.

  The ion permeation unit 21 substantially blocks the flow of water between the aerobic processing unit 13 and the anaerobic processing unit 14, and allows ammonium ions (NH4) and nitrite ions (NO2) to pass (diffuse). A material, for example, a sponge-shaped molded body, a filter cloth, a punching plate, or a combination thereof, or a plurality of baffle plates 23a alternately so that water does not flow directly as shown in FIG. , 23b to increase the water flow resistance.

  That is, the ion permeation unit 21 moves ions to the aerobic processing unit 13 and the anaerobic processing unit 14 by a diffusion phenomenon, thereby minimizing the movement of water. For this reason, the movement of the oxygen in water from the aerobic processing part 13 to the anaerobic processing part 14 is restrict | limited, and it can prevent that the anaerobic processing part 14 will be in an aerobic state. Moreover, since the diffusion rate of the organic compound having a large molecular weight compared to ions is relatively slow, it is possible to suppress the movement of the BOD component in the aerobic processing unit 13 to the anaerobic processing unit 14.

  The area ratio of the ion permeable part 21 and the water flow part 22 in the partition member 12 is the property of waste water to be treated, the volume of the treatment tank 11, the volume ratio of the aerobic treatment part 13 and the anaerobic treatment part 14, and the partition member. 12 can be set as appropriate according to various conditions such as the total area of 12, but normally, the area of the ion permeable portion 21 needs to be 70 to 99%. When dissolved oxygen flows into the processing unit 14 and the anaerobic state cannot be maintained and exceeds 99%, the above-described fouling suppressing effect is impaired.

  Moreover, the partition member 12 should just be able to suppress the distribution | circulation (convection) of the water between the aerobic process part 13 and the anaerobic process part 14, and does not need to be one sheet, A several sheet may be attached, As shown in FIG. 4, a structure in which a plurality of baffle plates 23 a and 23 b having through holes are arranged at appropriate intervals may be employed.

The material and shape of the partition member 12 can be selected as appropriate, but the water flow resistance as a whole needs to be a certain level or more. Here, when the water flow resistance is expressed by a water flow rate Q10 per unit area [m ² ] of the partition member 12 at a pressure of 10 kPa, the preferable water flow rate Q10 of the partition member 12 is 500 L / min / m ² or less, particularly Preference is given to 100 L / min / m ² . If the water flow rate Q10 is 500 L / min / m ² or less, liquid resistance for suppressing convection is secured, and ions can be moved preferentially. The surface area of the partition member 12 is made, it will vary with effluent characteristics, surface area per nitrogen load 1 kg-N / day 10 m ² or more preferably, 50 m ² or more is particularly preferable.

  On the other hand, nitrite ions (nitrite nitrogen) generated by oxidation of ammonium ions (ammonia nitrogen) dissolved in water by aeration treatment from the air diffuser 15 in the aerobic treatment unit 13 and unreacted The ammonium ions pass through the partition member 12 by diffusion according to the difference in ion concentration on both sides of the partition member 12 and move from the aerobic processing unit 13 to the anaerobic processing unit 14. The ammonium ions and nitrite ions that have moved to the anaerobic treatment unit 14 generate nitrogen gas by anaerobic ammonia oxidation, and the nitrogen gas is bubbled out of the system.

  The aerobic treatment unit 13 which is a nitrifying means is configured to nitrite ammonia nitrogen by a nitrifying bacterium (ammonia oxidizing bacterium) so that nitric acid is not generated to generate ammonium nitrite. In order to create an environment in which nitric acid is not easily generated, aeration is performed while maintaining the pH at 7 or higher with an alkaline agent. In addition, aeration can be controlled using a DO sensor or the like. As such nitritation means, a means for bringing ammonia nitrogen and nitrite bacteria into contact with each other under aerobic condition to nitrite ammonia nitrogen can be employed. Nitrite bacteria may be in a floating state, or may be in a state of being supported on a carrier such as a sponge, a resin molded body, or activated carbon.

  The nitrite bacteria used in the aerobic treatment unit 13 are bacteria conventionally used for nitritation of ammonia nitrogen, and oxidize ammonia nitrogen under aerobic condition to convert to nitrite nitrogen. Bacteria to do. Such nitrite bacteria can be generated by oxidizing a liquid containing ammoniacal nitrogen under aerobic conditions, but the sludge collected from the aerobic treatment means of organic wastewater treatment is used as it is or filled. It can be used attached to a layer. Normally, the inside of the aerobic processing unit 13 is in a uniform mixed state by aeration, but when the agitation force due to aeration is insufficient, agitation means such as an agitator and a circulation pump can be provided.

  The anaerobic treatment unit 14 which is a denitrification means is configured to denitrify the nitrite solution by reacting ammonia nitrogen and nitrite nitrogen with anaerobic ammonia oxidizing bacteria. Since anaerobic ammonia oxidizing bacteria are anaerobic, a structure in which oxygen is not supplied is employed. Anaerobic ammonia oxidizing bacteria may be used as floating sludge, or may be used in a state of being supported on a carrier or in a granular state such as granules. Alternatively, activated sludge in which anaerobic ammonia-oxidizing bacteria are prioritized can be used instead of anaerobic ammonia-oxidizing bacteria alone. In such denitrification means, a liquid containing ammonia nitrogen and nitrite nitrogen is brought into contact with anaerobic ammonia oxidizing bacteria, ammonia nitrogen and nitrite nitrogen are reacted, converted into nitrogen gas, and dehydrated. Nitrogen is performed.

  The anaerobic ammonia oxidizing bacterium used in the anaerobic treatment unit 14 belongs to Planctomycetes, and is an autotrophic bacterium, unlike the heterotrophic denitrifying bacterium used for conventional denitrification. For this reason, at the time of denitrification, it is not necessary to add a nutrient source such as methanol, which is necessary for conventional denitrifying bacteria. In addition, anaerobic ammonia-oxidizing bacteria react with ammonia nitrogen and nitrite nitrogen to convert them directly into nitrogen gas, so that ammonia nitrogen and nitrite nitrogen can be removed simultaneously, and waste is generated. It is difficult.

  Furthermore, anaerobic ammonia-oxidizing bacteria use ammonia nitrogen as an electron donor and nitrite nitrogen as an electron acceptor to react ammonia nitrogen and nitrite nitrogen directly to convert them into nitrogen gas. Nitrate nitrogen is not necessary, and the presence of oxygen reduces the denitrification activity of anaerobic ammonia oxidizing bacteria. Therefore, the anaerobic treatment unit 14 should be supplied with a liquid (waste water) that is substantially free of oxygen. Moreover, since anaerobic ammonia oxidizing bacteria cannot assimilate nitric acid, it is preferable that nitrate nitrogen is not substantially generated in the aerobic treatment unit 13. Since oxygen is consumed by bacteria while moving from the partition member 12 to the anaerobic treatment unit 14, an aeration amount is set so that dissolved oxygen disappears at the inlet portion of the anaerobic treatment unit 14 in the water flow unit 22. be able to.

  The anaerobic ammonia oxidizing bacteria react ammonia nitrogen and nitrite nitrogen at a molar ratio of 1: 1.32. However, the wastewater supplied to the anaerobic treatment unit 14 is nitrite nitrogen rather than ammonia nitrogen. The nitrous acid produced | generated in the aerobic process part 13 will pass the partition member 12 at any time, and will be in the state removed by the anaerobic process part 14. FIG.

  The waste water supplied to the aerobic treatment unit 13 has an ammoniacal nitrogen concentration of 500 mg / L or more, preferably 500 to 3000 mg / L, more preferably 500 to 2000 mg / L. If the ammonia nitrogen concentration is less than 500 mg / L, the concentration difference of the nitrogen component between the aerobic treatment unit 13 and the anaerobic treatment unit 14 is not sufficient, and the ion transfer rate is lowered, which is not preferable. It may be present if the nitrite nitrogen concentration is less than 300 mg / L, but if the nitrate nitrogen concentration exceeds 100 ppm, it is not removed because it remains in the treated water. The pH is preferably in the range of pH 6.5 to 9.0, preferably pH 7.0 to 8.5.

  The processing temperature in the aerobic processing unit 13 and the anaerobic processing unit 14 may be room temperature or higher, particularly 30 ° C. or higher, and may be heated at low temperatures. Moreover, a pH adjuster, a nutrient, and other additives can be inject | poured as needed. Furthermore, when sludge is generated excessively, a part of it may be extracted and discarded.

  In the anaerobic treatment unit 14, as described above, the anaerobic ammonia oxidizing bacteria react with ammonia nitrogen and nitrite nitrogen in the nitrite and convert it to nitrogen gas for denitrification. At this time, since the presence of dissolved oxygen decreases the activity of the anaerobic ammonia oxidizing bacteria, it is desirable that the dissolved oxygen does not flow into the anaerobic treatment unit 14. Although the partition member 12 shown in the present embodiment is provided with a water passage portion 22 in part, since the dissolved oxygen can be prevented from flowing directly into the anaerobic treatment portion 14 as a whole, the flow rate is larger than before. Can be anaerobic. Reaction by anaerobic ammonia oxidizing bacteria is shown in the following reaction formula (1), and ammonia nitrogen and nitrite nitrogen react at about 1: 1.32.

NH ₄ + 1.32NO ₂ − + 0.066HCO ₃ + 0.13H
→ 1.02N ₂ + 0.26NO ₃ − + 0.066CH ₂ O _0.5 N _0.15 + 2.03H ₂ O (1)

  In the above process, by treating the liquid of high ammonia nitrogen concentration and nitrite nitrogen with the aerobic treatment unit 13 and the anaerobic treatment unit 14, ammonia nitrogen is sublimated under conditions where nitric acid is not generated in the aerobic treatment unit 13. Nitrification can be performed, and denitrification can be performed with high efficiency in the anaerobic treatment unit 14 in the absence of oxygen.

  In the aerobic processing unit 13, it is not necessary to generate a nitrite having an ammonia nitrogen: nitrite nitrogen molar ratio of approximately 1: 1.32, and the generated nitrite ions pass through the partition member 12. Then, it moves to the anaerobic treatment part 14 and is converted into nitrogen gas by anaerobic ammonia oxidizing bacteria, so that nitrite ions do not accumulate. In addition, it is only necessary to oxidize ammonia nitrogen to nitrite nitrogen, and it is not necessary to oxidize nitrite nitrogen to nitrate nitrogen as in the past, so sludge containing nitrifying bacteria is unnecessary and supports nitrifying bacteria. Therefore, the processing tank 11 can be reduced in size and the amount of oxygen necessary for oxidation (aeration amount) can be reduced.

  In the anaerobic treatment unit 14, ammonia nitrogen and nitrite nitrogen are reacted at a molar ratio of approximately 1: 1.32 for denitrification. Therefore, no nutrient source such as methanol is required, and denitrification is performed efficiently. be able to. Moreover, it is harmless nitrogen gas produced | generated by denitrification reaction, and can be discarded as it is. Furthermore, since nitrifying bacteria and anaerobic ammonia oxidizing bacteria have a low growth rate, the amount of sludge increase is small, and the amount of surplus sludge generated is small.

  FIGS. 5A and 5B are front views showing various shape examples of the partition member 12, in which FIG. 5A shows the water passage portion 22 arranged in the vertical direction, and FIG. 5B shows the water passage portion 22. FIG. 5 (c) shows the intermittent arrangement of the water passages 22 in the horizontal and vertical directions, and the partition member 12 is a biological immobilization carrier. As a result, the sludge retention capacity is improved, the sludge that has been prioritized by nitrite oxidizing bacteria adheres to the partition member 12 on the aerobic treatment unit 13 side, and the anaerobic ammonia oxidizing bacteria has priority on the anaerobic treatment unit 14 side. It is conceivable that sludge adheres to the partition member 12. By using the partition member 12 of this type, DO and organic matter, which are components that are not preferable to move to the anaerobic treatment unit 14, are captured by the biological immobilization support before flowing into the anaerobic treatment unit 14, and ammonium Ions and nitrite ions diffuse in the anaerobic treatment unit 14 due to the concentration difference. In FIG. 5D, a large number of circular water passages 22 are arranged, and there is no clogging due to sludge and ion movement is not hindered, so that the ion movement speed can be maximized.

  FIG. 6 is a cross-sectional side view showing various shape examples of the partition member 12, and FIG. 6A is a view in which an inclined plate 24 is provided on the aerobic treatment part 13 side of the water flow part 22. By using such an inclined plate 24, the effective separation area of sludge can be increased. By making the inclined plate 24 face the anaerobic processing unit 14 side upward, sludge generated in the aerobic processing unit 13 cannot move up the gap between the inclined plates 24, and only water and ions can be moved to the anaerobic processing unit 14. . FIG. 6B corresponds to the cross-sectional side view of FIG. 5D described above, and shows a material having a fine water passage portion 22, for example, a punching metal. FIG. 6 (c) shows the baffle plate 25 arranged on the aerobic treatment unit 13 side of the water flow unit 22, and thus the baffle plate 25 is provided in front of the water flow unit 22, thereby convection of water. The water in the aerobic processing unit 13 is prevented from moving directly to the anaerobic processing unit 14 by convection. By forming the water flow portion 22 in this way, the pressure applied to the surface of the partition member 12 can be reduced, and sludge can be hardly adhered.

  FIG. 7 is a cross-sectional side view showing various arrangement examples when a plurality of the partition members 12 are provided. FIG. 7A is a partition having the inclined plate 24 shown in FIG. Two members 12 are provided, and by using two inclined plates 24 in this manner, sludge that has risen by aeration and did not settle on the first inclined plate 24 is precipitated in the second plate. be able to. Furthermore, it is possible to increase the sludge sedimentation efficiency by providing an appropriate interval between the inclined plates 24. By using the inclined plate 24, the effective separation area of sludge can be increased, and aerobic / anaerobic can be distinguished without dividing the inside of the reactor into two.

  FIG. 7B shows a partition member 12a having the inclined plate 24 shown in FIG. 6A and a partition member 12b having a water passage portion 22 on a flat plate. By providing an appropriate interval between the partition members 12b, the sludge sedimentation efficiency is increased, and sludge that cannot be captured by the inclined plate 24 can be sedimented at this portion.

  FIG. 7C shows an example in which an immobilization carrier 26 having a through hole 26a is provided on the anaerobic treatment portion 14 side of the partition member 12 having the inclined plate 24, and the partition member on the anaerobic treatment portion 14 side is used as the immobilization carrier. By making it 26, the amount of microorganisms retained can be increased. In addition, it is possible to segregate microorganisms such that ammonia oxidizing bacteria that consume DO are prioritized on the aerobic processing unit 13 side and anaerobic ammonia oxidizing bacteria are prioritized on the anaerobic processing unit 14 side. In addition, by using the immobilization carrier 26 as a partition member on the anaerobic treatment unit 14 side, it is possible to suppress the inflow of substances that inhibit anaerobic ammonia oxidizing bacteria such as DO and organic matter.

  FIG. 7D shows a flat plate provided with two partition members 12 each having a water passage portion 22, and FIG. 7E shows a through hole on the anaerobic treatment portion 14 side of the partition member 12 provided with a water passage portion 22. The one provided with the immobilization carrier 26 having 26a is shown. Sludge that flows out from the first through-hole 22 on the aerobic treatment unit 13 side settles between the second partition member 12 or the immobilization carrier 26 located on the anaerobic treatment unit 14 side. The convection of water is suppressed by staggering the positions of the water passage portions 22 and the through holes 26a, and movement due to the ion concentration difference between the aerobic treatment portion 13 and the anaerobic treatment portion 14 can be expected.

  FIG. 8 is a schematic system diagram showing another embodiment of the wastewater treatment apparatus of the present invention. Since the denitrification process is performed in the same manner as in the above-described embodiment, detailed description is omitted.

  The wastewater treatment apparatus shown in the present embodiment communicates an aerobic treatment tank 31 as an aerobic treatment part and an anaerobic treatment tank 32 as an anaerobic treatment part via a communication part 33 formed in the same manner as the partition member. The liquid in the anaerobic treatment tank 32 is circulated in the communication part 33 by the pump 34 through the circulation path, and ammonium ions are generated between the anaerobic liquid inside the communication part 33 and the external aerobic liquid. And nitrite ions are formed to move. Thus, the reaction efficiency in the anaerobic treatment tank 32 can be improved by generating the flow of the liquid in the anaerobic treatment tank 32 by the pump 34.

  DESCRIPTION OF SYMBOLS 11 ... Processing tank, 12 ... Partition member, 13 ... Aerobic processing part, 14 ... Anaerobic processing part, 15 ... Air diffuser, 16 ... Waste water introduction means, 17 ... Alkaline agent addition means, 18 ... pH meter, 19 ... Processing Water deriving means, 21 ... ion permeation part, 22 ... water passage part

Claims (4)

In a wastewater treatment apparatus for removing ammonia from wastewater having an ammoniacal nitrogen concentration of 500 ppm or more,
The aerobic treatment section that aeration-treats the wastewater introduced from the wastewater introduction means to oxidize ammonium ions in the wastewater to nitrite ions, and the generated nitrite ions and the ammonium ions in the wastewater react in an anaerobic state. Te with anaerobic processing unit for generating nitrogen gas, and suppresses the partition member and defining a flow of water between the aerobic section and the anaerobic treatment section Rutotomoni,
The aerobic treatment unit has means for introducing waste water and means for deriving treated water,
The partition member has an ion permeation part through which the ammonium ions and nitrite ions can pass due to a diffusion phenomenon, and the water flow resistance for suppressing the flow of water is such that the water flow rate at a pressure of 10 kPa is 500 L / min / m. A wastewater treatment apparatus characterized by being ² or less. The wastewater treatment apparatus according to claim 1, wherein a BOD concentration in the wastewater is 500 ppm or more . The wastewater treatment apparatus according to claim 1 or 2 , wherein the partition member is formed of a metallic water-permeable plate material . The wastewater treatment apparatus according to any one of claims 1 to 3 , wherein the ion permeable portion is one of a sponge-shaped molded body, a filter cloth, a punching plate, or a combination thereof .

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