JP2010188347A - Apparatus for treating wastewater containing organic sulfur compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain treated water of good quality by reducing generated malodor and performing a stable treatment in a simple facility in treating wastewater containing organic sulfur compounds by an apparatus with two or more vessels of aerobic bioreactors arranged in series. <P>SOLUTION: Two or more of the aerobic bioreactors 1-4 are connected in series and the wastewater containing organic sulfur compounds is dispensed into the two or more of aeration vessels 1-4. Since BOD loading volume per charged reactor is reduced by dispensing the wastewater containing organic sulfur compounds, amounts of oxygen demand per reaction vessel is reduced and oxygen deficiency status is easily prevented even without using any special aerator. Thereby, malodor is reduced which is originated by generation of DMS and MM caused by the reduction-atmosphere through oxygen deficiency. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus for biologically treating wastewater containing organic sulfur compounds such as DMSO (dimethyl sulfoxide) and sulfonic acids, and in particular, reducing odors generated when biologically treating organic sulfur compounds and treating water with good quality. The present invention relates to an organic sulfur compound-containing wastewater treatment apparatus that stably obtains water.

  In recent years, DMSO is increasingly used in semiconductor manufacturing processes and liquid crystal panel manufacturing processes. For example, in the field of liquid crystal panel production, a detergent obtained by adding DMSO to diethylene glycol monobutyl ether, 2-aminoethanol, 2,2-aminoethylaminoethanol or the like is used. For this reason, the processing method of these DMSO containing waste water is important.

  Since DMSO is biodegradable, biological treatment leads to economical treatment. However, when DMSO-containing wastewater is biologically treated, among the metabolites generated in the process of biodegradation of DMSO, DMS (methyl sulfide) ) And MM (methyl mercaptan) remained, and there was a problem that odors were generated from the aeration tank and treated water.

  Therefore, as an activated sludge treatment apparatus for DMSO-containing wastewater that has little residual DMS and MM and can adequately take measures against these bad odors, multiple aeration tanks connected in series and treated wastewater flow in. Means for diffusing the oxygen-containing gas in the first aeration tank and the diffused exhaust gas discharged from each upstream aeration tank connected to the downstream aeration tank are scattered in the next downstream aeration tank. An aerobic treatment comprising means for vaporizing, means for solid-liquid separation of the effluent of the first aeration tank, and means for returning sludge separated by the solid-liquid separation means to the first aeration tank An apparatus has been proposed (Japanese Patent No. 3331623).

  When attempting to decompose all organic matter in a single aeration tank, as in general activated sludge treatment equipment, there is a risk that some of the organic matter will flow out in an incompletely decomposed state due to the difference in organic matter decomposability and decomposition rate. is there. In particular, in DMSO decomposition, the decomposition rate from DMS to MM is expected to be lower than the decomposition rate from DMSO to DMS, and the DMS treatment will flow out with insufficient treatment.

  On the other hand, in the aerobic processing apparatus disclosed in Japanese Patent No. 3331623, even in the case of DMS that is insufficiently processed in the preceding aeration tank due to load and concentration fluctuations by performing aeration processing in multiple stages, the subsequent aeration tank Thus, it is possible to treat efficiently, and malodor due to residual DMS and MM is reduced.

In addition, in the biodegradation of DMSO, not only carbon and hydrogen but also sulfur must be oxidized, so the amount of oxygen required is very large. When a reducing atmosphere is formed due to lack of oxygen in the biological reaction tank, it causes generation of malodorous components such as DMS and MM as shown in the following reaction formula.
(CH ₃ ) ₂ SO + H ₂ → (CH ₃ ) ₂ S + H ₂ O
2 (CH ₃ ) ₂ SO + H ₂ → 2 (CH ₃ ) ₂ SH + 2H ₂ O

  Therefore, a method of keeping the dissolved oxygen in the biological reaction tank high and circulating the treated water (Japanese Patent No. 2776973) has also been proposed. In addition, an aeration apparatus that can supply a large amount of oxygen into the tank has also been proposed (Japanese Patent No. 3555557).

Japanese Patent No. 3331623 Japanese Patent No. 2776973 Japanese Patent No. 3555557

  Not only biological treatment of DMSO-containing wastewater, but a biological treatment reaction tank generally requires a large capacity, so that it may be necessary to divide into multiple tanks in order to ensure the strength of the reaction tank. Moreover, since the influence of the short path | pass of raw | natural water can be reduced by installing several reaction tanks in series, in order to obtain favorable treated water quality, it is desirable to connect and install several reaction tanks in series.

  However, when DMSO-containing wastewater is treated by connecting a plurality of reaction vessels in series, there are the following problems.

  That is, the first stage of a plurality of reaction tanks connected in series requires a large amount of oxygen because raw water flows in directly, and it tends to be a particularly reducing atmosphere. As a result, odors due to the generation of DMS and MM are generated. Problems are likely to occur, but it is not easy to supply sufficient oxygen to the first-stage reaction tank that requires a large amount of oxygen. Although the amount of dissolved oxygen can be increased by the aeration apparatus described in Japanese Patent No. 3555557, it is desired to cope with the problem without using such a special apparatus.

  In the case of the apparatus disclosed in Japanese Patent No. 3331623, the problem of bad odor can be solved by supplying the exhaust gas from the preceding aeration tank to the subsequent aeration tank and aeration. The aeration equipment that sucks in the exhaust gas in the aeration tank is likely to be corroded, and oxygen is consumed in the preceding aeration tank and the oxygen concentration is lowered, so the aeration efficiency in the latter stage is poor. Power increases. Moreover, since the upper part of the aeration tank is sealed, there is a problem that the equipment cost is high.

  Note that such a problem is not limited to DMSO, but is similarly a problem in the treatment of wastewater containing organic sulfur compounds such as sulfonic acids.

  Therefore, the present invention reduces the odor generated by simple equipment and performs stable treatment when treating organic sulfur compound-containing wastewater with an apparatus in which two or more aerobic biological reaction tanks are arranged in series. It is an object of the present invention to provide an organic sulfur compound-containing wastewater treatment apparatus for obtaining treated water with good water quality.

The apparatus for treating organic sulfur compound-containing wastewater of the present invention (Claim 1) is an apparatus for introducing and treating organic sulfur compound-containing wastewater into an aerobic biological reaction tank. The organic sulfur compound-containing wastewater treatment apparatus is arranged in series so as to supply the effluent of the reaction tank to the next-stage reaction tank, and the organic sulfur compound-containing wastewater is dispensed into the plurality of reaction tanks. In addition, three or more aerobic biological reaction tanks are arranged, and the organic sulfur compound-containing wastewater is not dispensed into the foremost reaction tank, and the organic sulfur compound-containing wastewater is not dispensed into the reaction tank. It is characterized by supplying wastewater containing organic matter other than compound-containing wastewater .

The treatment apparatus for organic sulfur compound-containing wastewater according to claim 2 is characterized in that, in claim 1, three or more aerobic biological reaction tanks are arranged, and at least the last-stage reaction tank does not dispense organic sulfur compound-containing wastewater. It is characterized by .

Processor of the organic sulfur compounds containing waste water 請 Motomeko 3 resides in that in Claim 1 or 2, aerobic biological reactor is characterized by a aeration tank with the addition of biological carrier.

The organic sulfur compound-containing wastewater treatment apparatus according to claim 4 is characterized in that, in any one of claims 1 to 3 , a pH adjusting means is provided in the reaction tank for dispensing the organic sulfur compound-containing wastewater. .

  According to the organic sulfur compound-containing wastewater treatment apparatus of the present invention, the organic sulfur compound-containing wastewater is dispensed into a plurality of aerobic biological reaction tanks arranged in series, thereby reducing odor with the following mechanism of action. be able to.

  That is, by dispensing the organic sulfur compound-containing wastewater, the BOD load per reaction tank to be injected is reduced, so that the oxygen demand per reaction tank is reduced and even without using a special aeration device. It becomes possible to prevent an oxygen-deficient state from being easily obtained. For example, in an apparatus in which four reaction tanks are arranged in series, when the entire amount of organic sulfur compound-containing wastewater is injected into the first reaction tank, the required oxygen amount in each reaction tank is the first stage: the second stage Eye: Third stage: Fourth stage = 4: 2: 1: 1 It is biased to the previous stage, and oxygen tends to be deficient in the previous stage. On the other hand, according to the present invention, if the organic sulfur compound-containing wastewater is dispensed into the first, second, and third stage reaction tanks, the oxygen requirement as a whole is the same as the first. Stage: 2nd stage: 3rd stage: 4th stage = 2: 2: 2: 2 The required amount of oxygen is averaged in each tank, and it is difficult for oxygen to become extremely short. For this reason, the odor resulting from generation | occurrence | production of odorous substances, such as DMS and MM, by becoming a reducing atmosphere with oxygen shortage is reduced.

  The organic sulfur compound-containing wastewater treatment apparatus of the present invention is only required to provide a pipe for dispensing the organic sulfur compound-containing wastewater to the reaction tank arranged in multiple stages, and a special aeration device, exhaust gas suction means, etc. are provided. It is not necessary and can be realized at low cost with simple equipment.

  According to the treatment apparatus for organic sulfur compound-containing wastewater according to claim 2, by arranging three or more aerobic biological reaction tanks and not dispensing organic sulfur compound-containing wastewater into the last reaction tank, The organic sulfoxide is sufficiently decomposed and removed by preventing a short pass, and the reaction tank in the last stage is not loaded with the organic sulfur compound, so that the residual TOC is efficiently decomposed and obtained in this reaction tank. The TOC of treated water can be sufficiently reduced.

According to the organic sulfur compound-containing wastewater treatment apparatus of the present invention , three or more aerobic biological reaction tanks are arranged, and other organic substances other than organic sulfur compound-containing wastewater are contained in a reaction tank that does not dispense organic sulfur compound-containing wastewater. By supplying wastewater, other organic matter-containing wastewater can be treated at the same time. In this case, by supplying other organic matter-containing wastewater to a reaction tank that does not dispense organic sulfur compound-containing wastewater, and not supplying other organic matter-containing wastewater to a reaction tank that dispenses organic sulfur compound-containing wastewater, In a reaction tank that dispenses sulfur compound-containing wastewater, organic sulfur compound assimilating bacteria are predominated, the decomposition efficiency of organic sulfur compounds is increased, and other organic matter loads are suppressed to prevent oxygen shortage. Decomposition can be promoted, and the TOC of the final treated water can be sufficiently reduced.

According to the organic sulfur compound-containing wastewater treatment apparatus of claim 3 , by using an aeration tank to which a biological carrier is added, the organic sulfur compound-assimilating bacteria are attached to the carrier and maintained in a high concentration in the tank. The decomposition efficiency of organic sulfur compounds can be increased.

According to the treatment apparatus for organic sulfur compound-containing wastewater according to claim 4 , by adjusting the pH in each reaction tank for dispensing the organic sulfur compound-containing wastewater, the reaction activity is reduced due to the decrease in pH due to the decomposition of the organic sulfur compound. It can prevent and perform efficient processing.

It is a system diagram showing a processing equipment of the organic sulfur compounds containing waste water according to a reference example. It is a system diagram showing a processing MakotoSo location of the organic sulfur compounds containing waste water according to a reference example. Embodiments of the organic sulfur compounds containing waste water treatment apparatus of the present invention is a system diagram showing.

  Embodiments of the organic sulfur compound-containing wastewater treatment apparatus of the present invention will be described in detail below.

  In the following, the present invention will be described by exemplifying a case where DMSO-containing wastewater is treated as organic sulfur compound-containing wastewater. However, the present invention is not limited to DMSO, and wastewater containing sulfonic acids and other organic sulfur compounds is described. Can be applied similarly.

[DMSO-containing wastewater]
The DMSO-containing wastewater to be treated in the present invention is a wastewater containing DMSO discharged from a semiconductor factory, a liquid crystal factory, or other fields, and may contain only DMSO, and TMAH (tetramethylammonium hydrooxy). Site), wastewater containing 2-aminoethanol, isopropyl alcohol and the like at the same time, or wastewater mixed with DMSO-containing wastewater and other organic matter-containing wastewater. In addition, DMSO-containing wastewater includes those containing DMSO at a high concentration and those that are diluted and discharged as medium-concentration and low-concentration wastewater.

[Aerobic biological reactor]
In the present invention, the aerobic bioreactor used in plural is not particularly limited, and any commonly used bioreactor can be used.

  For example, a floating system in which sludge (microorganisms) is held in a floating state in an aeration tank equipped with oxygen supply means such as an air diffuser and a mechanical aerator, a carrier addition system in which a microorganism holding carrier is present together with floating sludge, activated carbon, etc. Various methods such as a biofiltration method in which a fixed bed is formed, a fluidized bed method in which the packed bed is fluidized, a floating packed bed method in which a floating carrier is used, and a sludge blanket method in which a microbial sludge layer is formed. Can be used.

  When a biological carrier is used, any carrier such as a sponge piece or activated carbon can be used as the carrier. Since the sponge has a large surface area, excellent water permeability to the inside, and specific gravity is close to water, it is suitable for holding DMSO-assimilating bacteria. The added amount of the biological carrier is preferably about 20 to 50% in apparent volume with respect to the volume of the reaction vessel.

  When it is necessary to separate the treated water and sludge using a floating reaction tank or the like, for example, solid-liquid separation means such as a precipitation tank or a membrane filtration device is attached. Part of the separated sludge is returned to the aerobic biological reaction tank at the foremost stage as return sludge. When the biological carrier is introduced into the aerobic biological reaction tank, solid-liquid separation means such as a subsequent precipitation tank can be dispensed with.

  Note that the aerobic biological reaction tanks used in plurality need not be the same type reaction tanks, but may be used in combination with different types of reaction tanks.

[Nutrition source]
In order for microorganisms to maintain activity and grow, a carbon source, a nitrogen source, and a phosphorus source are required, and various trace metals are also indispensable. When these nutrient sources are present in the wastewater to be treated, it is not necessary to add them. However, in the case of DMSO-containing wastewater, it is usually necessary to add nitrogen and phosphorus.

  Ammonia compounds, urea, nitrogen-containing organic compounds, etc. can be used as the nitrogen source, and phosphates can be used as the phosphorus source. In addition, wastewater containing Kjeldahl nitrogen components such as ammonia and nitrogen-containing organic compounds, for example, the above-mentioned TMAH wastewater may be used as a nitrogen source, or phosphoric acid-containing wastewater may be used as a phosphorus source.

  In general, the BSO: N: P of the wastewater to be treated is 100: 2.5: 0.5 to 100: 5: 1 (weight ratio). It is preferable to add and introduce into an aerobic biological reaction tank.

[Aerobic treatment conditions]
As processing conditions for the aeration tank, the load on the aerobic biological reaction tank is usually 0.5 kg-BOD / m ³ / day or less, for example, 0.3 to 0.4 kg-BOD / m ³ / day, MLSS 3000 to 5000 mg / day. L, for example, about 4000 mg / L, reaction time of 1 hour or longer, for example, 2 to 8 hours, pH is preferably adjusted to 6.5 to 8.5, particularly 7.0 to 8.0.

  In the treatment of DMSO-containing wastewater, the pH decreases due to the decomposition of DMSO. Therefore, it is possible to adjust the pH to the above pH by adding an alkali such as sodium hydroxide or alkaline wastewater, etc. to maintain the decomposition efficiency of DMSO. Therefore, it is preferable. This pH adjustment is preferably performed in all of the reaction tanks into which DMSO-containing wastewater is dispensed. In some cases, DMSO-containing wastewater in the next stage of the reaction tank into which DMSO-containing wastewater has been dispensed is not dispensed. It is preferable to adjust the pH also in the reaction vessel.

  In addition, the dissolved oxygen (DO) concentration in the reaction tank into which at least DMSO-containing wastewater is dispensed is 0.5 mg / L or more, particularly 1.5 mg / L or more, for example, 1.5 to 2.0 mg / L. It is preferable to perform aeration.

[Dispensing of DMSO-containing wastewater]
In the DMSO-containing wastewater treatment apparatus of the present invention, three or more aerobic biological reaction tanks are arranged in series so that the effluent of the previous reaction tank is supplied to the next reaction tank, and the DMSO-containing wastewater is disposed. Must be dispensed into two or more reaction vessels.

  In this case, in the reaction tank in which DMSO-containing wastewater is dispensed, a short pass of partial raw water occurs, and there is a possibility that the untreated DMSO-containing wastewater partially flows out to deteriorate the quality of the treated water. For this reason, in order to prevent deterioration of water quality due to such a short pass, it is preferable not to dispense DMSO-containing wastewater into the last reaction tank. Further, as will be described later, a reaction tank that does not dispense DMSO-containing wastewater is used particularly when high-quality treated water is required, such as when the treated water of the apparatus of the present invention is used as raw water for producing pure water. It is preferable not to dispense DMSO-containing wastewater into the last-stage reaction tank and the reaction tank immediately before the two-stage or more. Thus, by not dispensing DMSO-containing wastewater into the last stage reaction tank or the reaction tank immediately before it, not only prevents a short pass of DMSO-containing wastewater, but also a reaction tank that does not dispense DMSO-containing wastewater. By not applying a load with DMSO, the decomposition efficiency of the residual TOC can be increased, and the treated water TOC can also be reduced by this.

In the present invention, the number of reaction tanks connected in series is not particularly limited, and is appropriately determined in consideration of the quality of DMSO-containing wastewater to be treated, the required odor reduction effect, equipment installation space, cost, and the like. . In normal cases, it is preferable to provide 3 to 6 tanks, particularly about 4 to 5 tanks.

  The odor reduction effect can be enhanced by increasing the ratio of the reaction tank capacity for dispensing DMSO-containing wastewater to the reaction tank capacity of the entire apparatus. The problem of deterioration is likely to occur. Therefore, the ratio of the reaction tank capacity for dispensing DMSO-containing wastewater to the reaction tank capacity of the entire apparatus is preferably 30 to 90%, particularly 50 to 80%. In addition, the capacity | capacitance of each reaction tank does not necessarily need to be the same, and may differ.

  The amount of DMSO-containing wastewater to be dispensed is preferably adjusted so that the BOD tank load of each reaction tank to which DMSO-containing wastewater is dispensed is equivalent. Therefore, it is preferable that the raw water injection means to each reaction tank is capable of adjusting the raw water flow rate, respectively, and a TOC meter and a conductivity meter are installed in order to detect a change in the influent water quality. Based on these values, the amount of flow into each reaction tank may be controlled. In addition, a DO meter may be installed in a reaction tank that dispenses DMSO-containing wastewater, and the dispensing amount may be controlled so that the DO value of each reaction tank is averaged. As described later, when treating wastewater containing DMSO and wastewater containing other organic substances, if the BOD can be estimated from the TOC or conductivity, the BOD load of each reaction vessel is injected from these measured values to be equivalent. It is preferred to control the amount.

  Therefore, although the apparatus of the present invention is designed to have reaction tanks arranged in series in multiple stages and provided with pipes for dispensing raw water, the number of reaction tanks to be dispensed increases or decreases due to fluctuations in the water quality of DMSO-containing wastewater. In particular, when the DMSO concentration of the DMSO-containing wastewater temporarily decreases, the DMSO-containing wastewater can be injected into only one reaction tank. Moreover, it is possible to change the reaction tank to be dispensed according to the presence or absence of introduction of other organic matter-containing wastewater, and these controls can be automatically performed.

[Other organic wastewater]
In the apparatus of the present invention, other organic matter-containing wastewater such as wastewater from other processes in the semiconductor manufacturing process and liquid crystal panel manufacturing process, such as wastewater from TMAH, wastewater containing MEA (monoethanolamine), and wastewater containing acetic acid, together with DMSO-containing wastewater. Can be treated simultaneously and other organics can be decomposed together with DMSO.

In this case, other organic matter containing wastewater introduced into a reaction vessel that is not dispensed DMSO containing wastewater minute. Particularly reactor to introduce other organic matter containing wastewater, the reaction vessel at the first stage and those to introduce other organic matter containing wastewater in the reaction vessel at the first stage, DMSO-containing waste water in the reaction vessel of the second stage and thereafter minute refers to that. This is because, in a reaction tank that treats DMSO-containing wastewater, it is desirable to reduce the presence of other organic substances in order to make DMSO-utilizing bacteria predominate as much as possible. This is for preventing the deficiency and promoting the decomposition of DMSO.

  That is, for example, wastewater containing TMAH-containing wastewater components such as TMAH-containing wastewater is a nitrogen source, but consumes a large amount of oxygen to be oxidized to nitrate nitrogen by biological treatment. Therefore, such other organic matter-containing wastewater is preferably introduced into the previous reaction tank so that it does not become an oxygen consumption source in the reaction tank into which DMSO-containing wastewater is dispensed. Thus, even when other organic matter-containing wastewater is treated at the same time, the TOC of the final treated water is reduced by distinguishing between the introduction reaction tank for organic matter-containing wastewater and the dispensing reaction tank for DMSO-containing wastewater. Is preferred. It should be noted that the reaction tank into which other organic matter-containing wastewater is injected and DMSO-containing wastewater is not dispensed does not need to be maintained at a higher DO concentration than the reaction tank into which DMSO-containing wastewater is dispensed. The aeration cost can be reduced by lowering.

[Recovered water]
After the DMSO-containing waste water is treated, the treated water can be discharged, but can be reused for any purpose. For example, when the treated water is used as raw water for producing pure water, the apparatus of the present invention is followed by a membrane separation apparatus such as a reverse osmosis membrane separation apparatus, a mixed bed type pure water apparatus, a two-bed three-column type pure water apparatus. Water is passed through a pure water production system that is formed by arbitrarily combining various devices such as ion exchange equipment such as continuous electric desalting equipment, oxidation equipment such as ultraviolet oxidation equipment, adsorption equipment such as activated carbon towers, and degassing equipment. Thus, pure water can be obtained.

  In this case, in the apparatus of the present invention, it is preferable to reduce the TOC of the treated water as much as possible to reduce the load on the pure water production apparatus. Therefore, in order to further reduce the treated water TOC, as described above, the last DMSO wastewater is not dispensed to the stage reaction tank; moreover, a reaction tank that does not dispense DMSO-containing wastewater more than two stages is installed; when other organic-containing wastewater is treated, the other organic-containing wastewater is the first stage It is preferable to carry out such adjustment that the DMSO-containing waste water is dispensed into the second and subsequent reaction vessels.

[Specific equipment configuration]
1 and 2 are system diagrams showing a DMSO-containing wastewater treatment apparatus according to a reference example, and FIG. 3 is a systematic diagram showing an embodiment of a DMSO-containing wastewater treatment apparatus according to the present invention.

  1-3, all four aerobic biological reaction tanks (aeration tanks) 1 to 4 are arranged in series, and the effluent of the first aeration tank 1 is introduced into the second aeration tank 2 through the pipe 21. Then, the effluent of the second aeration tank 2 is introduced into the third aeration tank 3 through the pipe 22, the effluent of the third aeration tank 3 is introduced into the fourth aeration tank 4 through the pipe 23, and the fourth aeration tank 4 The effluent is introduced into the sedimentation tank 5 from the pipe 24, the supernatant water of the sedimentation tank 5 is discharged from the system as treated water from the pipe 25, and a part of the separated sludge in the sedimentation tank 5 is removed from the system as excess sludge from the pipe 26. The remaining portion is returned to the first aeration tank 1 as return sludge from the pipe 20. In addition, in the apparatus of FIG. 3, the biological carrier 6 is thrown into each aeration tank 1-4.

  In the apparatus of FIG. 1, DMSO-containing wastewater introduced from a pipe 10 is dispensed into the aeration tanks 1 to 4 through pipes 11, 12, and 1314. In this apparatus, DMSO-containing wastewater is dispensed into four aeration tanks, so that odor can be reduced.

  In the apparatus of FIG. 2, DMSO-containing wastewater introduced from the pipe 10 is dispensed into the aeration tanks 1 to 3 other than the fourth aeration tank 4 at the last stage through the pipes 11, 12, and 13. In the apparatus of FIG. 2, DMSO-containing wastewater is dispensed into three aeration tanks other than the last stage, thereby reducing odor and improving the quality of treated water.

  In the apparatus of FIG. 3, the TMAH-containing wastewater introduced from the pipe 30 is injected into the first aeration tank 1, and the DMSO-containing wastewater introduced from the pipe 10 is connected to the first aeration tank 1 and the first aeration tank 1 through the pipes 12 and 13. It is introduced into the second and third aeration tanks 2 and 3 other than the four aeration tanks 4. In the apparatus of FIG. 3, TMAH-containing wastewater can be treated together with DMSO-containing wastewater. In this case, TMAH-containing wastewater can be effectively used as a nitrogen source. In addition, TMAH-containing wastewater is injected into an aeration tank before that which is different from the aeration tank that dispenses DMSO-containing wastewater, and DMSO-containing wastewater other than the aeration tank into which TMAH-containing wastewater is injected and the last aeration tank In addition to aliquoting, the use of a biological carrier can reduce the odor and reduce and stabilize the quality of the treated water.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

The first to fourth aeration tanks 1 to 4 used in the following examples and comparative examples are all having a capacity of 100 L, MLSS: 4000 mg / L, DO: 0.1 to 2.5 mg / L. The pH was adjusted to 7.0 to 8.0. The sedimentation tank 5 had a separation area of 0.5 m ² , and the amount of sludge returned from the sedimentation tank 5 to the first aeration tank 1 was 1440 L / day.

Moreover, the water quality of DMSO containing waste water used as raw water was as follows, and the amount of raw water treated was 1440 L / day.
[DMSO-containing wastewater]
Solubility TOC: 45.2 mg / L
DMSO: 62.3 mg / L
Kjeldahl nitrogen: 0.5 mg / L

Reference example 1
With the apparatus shown in FIG. 1, the raw water was dispensed into each of the first to fourth aeration tanks 1 to 4 by 15 L / h for treatment. In addition, nitrogen and phosphorus were added to the raw water so that BOD: N: P was 100: 5: 1 (weight ratio) assuming that 3 times the TOC was BOD.
The quality of the treated water obtained and the DMS concentration in each aeration tank exhaust were examined, and the results are shown in Table 1.

Reference example 2
Using the apparatus shown in FIG. 2, the raw water was treated in the same manner as in Reference Example 1 except that 20 L / h was dispensed into the first to third aeration tanks 1 to 3, and the quality of the treated water obtained was Table 1 shows the DMS concentration in each aeration tank exhaust.

Example 1
As shown in FIG. 3, using a device in which 30% of the tank capacity was added to each aeration tank 1 to 4 with an apparent volume of 3 mm square, raw water was supplied to the second to third aeration tanks 2 and 3 at 30 L / h. In addition to dispensing the TMAH-containing wastewater having the following water quality to the first aeration tank 1, assuming that 3 times the TOC of the raw water is BOD, phosphorus is added so that BOD: P becomes 100: 1 (weight ratio). The treatment was conducted in the same manner as in Reference Example 1 except that the quality of the treated water obtained and the DMS concentration in each aeration tank were shown in Table 1.
[TMAH-containing wastewater]
Solubility TOC: 32.8 mg / L
TMAH: 53.8 mg / L
Kjeldahl nitrogen: 12.3 mg / L

Comparative Example 1
The treatment was performed in the same manner as in Reference Example 1 except that all the raw water was injected into the first aeration tank 1, and the water quality of the obtained treated water and the DMS concentration in each aeration tank exhaust are shown in Table 1.

Comparative Example 2
The treatment was performed in the same manner as in Reference Example 3 except that all the raw water was injected into the first aeration tank 1, and the quality of the obtained treated water and the DMS concentration in each aeration tank exhaust are shown in Table 1.

  From Table 1, the following is clear.

Compared with Comparative Example 1, the odors in both Reference Examples 1 and 2 are greatly reduced. In particular, in Reference Example 2, a good treated water quality equivalent to that of Comparative Example 1 is obtained.

Moreover, compared with the comparative example 2, in Example 1 , an odor is reduced significantly and the equivalent favorable treated water quality is obtained.

  From these results, it can be seen that according to the present invention, generation of malodor is suppressed with a simple treatment facility, and a stable treated water quality can be obtained.

DESCRIPTION OF SYMBOLS 1 1st aeration tank 2 2nd aeration tank 3 3rd aeration tank 4 4th aeration tank 5 Sedimentation tank 6 Carrier

Claims (6)

  In an apparatus for introducing and treating organic sulfur compound-containing wastewater into an aerobic biological reaction tank, two or more aerobic biological reaction tanks are supplied with the effluent of the previous reaction tank supplied to the subsequent reaction tank. An organic sulfur compound-containing wastewater treatment apparatus, wherein the organic sulfur compound-containing wastewater is dispensed into a plurality of the reaction tanks.   3. The apparatus for treating organic sulfur compound-containing wastewater according to claim 1, wherein three or more aerobic biological reaction vessels are disposed, and the organic sulfur compound-containing wastewater is not dispensed into at least the last reaction vessel.   3. The aerobic biological reaction tank according to claim 1 or 2, wherein three or more aerobic biological reaction tanks are disposed, and at least one of the reaction tanks does not dispense organic sulfur compound-containing wastewater, and does not dispense organic sulfur compound-containing wastewater. An organic sulfur compound-containing wastewater treatment apparatus that supplies wastewater containing organic matter other than organic sulfur compound-containing wastewater to a reaction tank.   4. The organic sulfur compound-containing wastewater treatment apparatus according to claim 3, wherein the aerobic biological reaction tank in which the organic sulfur compound-containing wastewater is not dispensed is the frontmost reaction tank.   5. The organic sulfur compound-containing wastewater treatment apparatus according to any one of claims 1 to 4, wherein the aerobic biological reaction tank is an aeration tank to which a biological carrier is added.   6. The organic sulfur compound-containing wastewater treatment apparatus according to any one of claims 1 to 5, wherein pH adjusting means is provided in the reaction tank for dispensing the organic sulfur compound-containing wastewater.

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