JP2010017671A - Method and apparatus for treating dimethyl sulfoxide-containing organic wastewater - Google Patents

Abstract

DMSO is not completely decomposed but recovered from wastewater for reuse, and organic wastewater is treated.
The DMSO-containing wastewater treatment apparatus of the present invention enables reuse of DMS as a DMSO synthesis raw material by decomposing DMSO in wastewater into DMS in an anaerobic treatment tank and then evaporating and collecting DMS. Suppresses generation of odorous gas due to decomposition of DMS. The organic matter-containing wastewater after the anaerobic biological treatment treats organic matters other than DMSO in an aerobic treatment tank.
[Selection] Figure 2

Description

The present invention relates to an apparatus for efficiently treating waste water containing dimethyl sulfoxide (DMSO). In particular, the present invention relates to a wastewater treatment apparatus having a step of separating and recovering methyl sulfide (DMS) into a gas phase.

In recent years, a large amount of DMSO is used in the peeling and cleaning processes in the manufacture of semiconductors and liquid crystal panels, and a large amount of DMSO-containing waste water is treated in these manufacturing plants. In addition, DMSO-containing wastewater is increasing year by year as semiconductor and liquid crystal panel production increases.

The treatment of the wastewater containing DMSO can be carried out by biological treatment using acclimatized bacteria, and the activated sludge method is widely used.

FIG. 1 is a diagram showing a biodegradation pathway of DMSO. In the wastewater treatment process, DMSO is first reduced to DMS and then oxidized by the reaction route shown in FIG.

In the conventional wastewater treatment method using the reaction path of FIG. 1, it is necessary to maintain the aerobic biological treatment tank under sufficient aerobic conditions in order to quickly decompose DMS produced from DMSO into sulfate ions. is there. However, it is difficult to maintain the aerobic biological treatment tank under highly aerobic conditions, and there is a problem that odorous gases such as methyl mercaptan (MM) and hydrogen sulfide, which are DMS decomposition intermediates, are generated. For this reason, the aerobic biological treatment of wastewater containing DMS requires more aeration energy than the aerobic biological treatment of wastewater not containing DMS, and there is also a problem that a large amount of excess sludge is generated. .

Various ideas have been made to solve these problems. For example, the patent document 1 that improves the decomposition efficiency of DMSO or a patent that uses a biological treatment means and a chemical or physical treatment means in combination. The processing method of Document 2 has been reported.

As described above, the conventional treatment of DMSO-containing wastewater has been aimed at decomposing DMSO. On the other hand, the significant increase in demand for semiconductors and liquid crystal panels in recent years is a prediction of a significant increase in demand for DMSO in the future, and the need to collect and reuse DMSO in wastewater is expected to increase in the future. It is something to be made.

Japanese Patent No. 3271322 Japanese Patent Laid-Open No. 2000-254661

The object of the present invention is not to completely decompose DMSO, but to recover it from wastewater for reuse and to treat wastewater containing organic matter.

According to one embodiment of the present invention, the organic matter-containing wastewater containing dimethyl sulfoxide is subjected to anaerobic biological treatment to decompose the organic matter other than dimethyl sulfoxide and produce methyl sulfide, and vaporize the produced methyl sulfide. Separating the methyl sulfide from the organic matter-containing wastewater, subjecting the organic matter-containing wastewater from which the methyl sulfide has been separated to aerobic biological treatment, and subjecting the organic matter-containing wastewater subjected to the aerobic biological treatment to solid-liquid separation treatment And providing a method for treating wastewater containing organic matter containing dimethyl sulfoxide, wherein at least part of the sludge subjected to the solid-liquid separation treatment is returned to the anaerobic biological treatment step and the aerobic biological treatment step. Is done.

Further, according to an embodiment of the present invention, an organic substance other than dimethyl sulfoxide is mixed with an organic substance-containing wastewater containing dimethyl sulfoxide, and the organic substance other than dimethyl sulfoxide is decomposed by anaerobic biological treatment of the organic substance-containing wastewater. And by producing the methyl sulfide and vaporizing the produced methyl sulfide, the methyl sulfide is separated from the organic matter-containing wastewater, the organic matter-containing wastewater from which the methyl sulfide is separated is subjected to an aerobic biological treatment, The organic matter-containing wastewater that has been subjected to aerobic biological treatment is subjected to solid-liquid separation treatment, and at least part of the sludge subjected to the solid-liquid separation treatment is returned to the anaerobic biological treatment step and the aerobic biological treatment step. A method for treating wastewater containing organic matter containing dimethyl sulfoxide is provided.

Further, the methyl sulfide may be separated from the organic matter-containing waste water by aerating a gas not containing oxygen to the organic matter-containing waste water and vaporizing the generated methyl sulfide.

Moreover, you may isolate | separate the said methyl sulfide from the said organic substance containing waste_water | drain by sprinkling the said organic substance containing waste_water | drain containing the said methyl sulfide and aerating the gas which does not contain oxygen by an upward flow.

The methyl sulfide separated from the organic matter-containing waste water is recovered.

Moreover, you may collect | recover the said methyl sulfide isolate | separated from the said organic substance containing waste water with the adsorption agent containing the porous silica or activated carbon which was processed with nitric acid.

Further, a methyl sulfide-containing solution can be obtained by bringing dimethyl sulfoxide or paraffinic hydrocarbon into contact with the adsorbent on which the methyl sulfide is adsorbed.

Further, according to one embodiment of the present invention, an organic matter-containing wastewater containing dimethyl sulfoxide is subjected to anaerobic biological treatment to decompose the organic matter other than dimethyl sulfoxide and produce methyl sulfide, and vaporize the produced methyl sulfide. A first tank for separating the methyl sulfide from the organic matter-containing wastewater, a second tank for treating the organic matter-containing wastewater from which the methyl sulfide has been separated, and the aerobic organism. A third tank for solid-liquid separation treatment of the treated organic matter-containing wastewater; and a mechanism for returning at least a part of the solid-liquid separation treated sludge to the first tank and the second tank; An apparatus for treating wastewater containing organic matter containing dimethyl sulfoxide is provided.

In addition, according to an embodiment of the present invention, an organic matter-containing wastewater containing dimethyl sulfoxide is subjected to anaerobic biological treatment, thereby decomposing the organic matter other than dimethyl sulfoxide and generating methyl sulfide. A fourth tank for separating the methyl sulfide from the organic matter-containing wastewater by vaporizing the methyl sulfide; and a second tank for aerobic biological treatment of the organic matter-containing wastewater from which the methyl sulfide is separated; A third tank for solid-liquid separation treatment of the organic substance-containing wastewater that has been subjected to the aerobic biological treatment, and at least a part of the sludge subjected to the solid-liquid separation treatment are placed in the first tank and the second tank. And a mechanism for returning the organic wastewater containing dimethyl sulfoxide.

Further, according to an embodiment of the present invention, an organic substance other than dimethyl sulfoxide is mixed with an organic substance-containing wastewater containing dimethyl sulfoxide, and the organic substance other than dimethyl sulfoxide is decomposed by anaerobic biological treatment of the organic substance-containing wastewater. In addition, by generating methyl sulfide and vaporizing the generated methyl sulfide, the first tank for separating the methyl sulfide from the organic matter-containing wastewater and the organic matter-containing wastewater from which the methyl sulfide has been separated are aerobic. A second tank for biological treatment, a third tank for solid-liquid separation treatment of the organic substance-containing wastewater subjected to the aerobic biological treatment, and at least a part of the sludge subjected to the solid-liquid separation treatment, And a mechanism for returning to the second tank, and an organic matter-containing wastewater treatment apparatus containing dimethyl sulfoxide is provided. That.

According to one embodiment of the present invention, the first tank for mixing organic matter other than dimethyl sulfoxide with the organic matter-containing wastewater containing dimethyl sulfoxide, and vaporizing the generated methyl sulfide, thereby converting the methyl sulfide to the organic matter. A fourth tank for separating the wastewater from the wastewater; a second tank for aerobic biological treatment of the organic matter-containing wastewater from which the methyl sulfide has been separated; and the organic matter-containing wastewater that has been aerobically biologically treated. A dimethyl sulfoxide comprising: a third tank for separation treatment; and a mechanism for returning at least part of the sludge subjected to the solid-liquid separation treatment to the first tank and the second tank. An organic matter-containing wastewater treatment apparatus is provided.

Further, the methyl sulfide may be separated from the organic matter-containing waste water by aerating a gas not containing oxygen to the organic matter-containing waste water and vaporizing the generated methyl sulfide.

Moreover, you may isolate | separate the said methyl sulfide from the said organic substance containing waste_water | drain by sprinkling the said organic substance containing waste_water | drain containing the said methyl sulfide and aerating the gas which does not contain oxygen by an upward flow.

Moreover, the recovery apparatus which collect | recovers the said methyl sulfide isolate | separated from the said organic substance containing waste_water | drain is provided.

Moreover, you may provide the adsorption | suction apparatus which collect | recovers the said methyl sulfide isolate | separated from the said organic substance containing waste_water | drain with the adsorption agent containing the porous silica or activated carbon treated with nitric acid.

Moreover, you may provide the adsorption | suction apparatus which collect | recovers methyl sulfide containing solutions by making dimethyl sulfoxide or paraffinic hydrocarbon contact the said adsorption agent to which the said methyl sulfide adsorb | sucked.

According to the DMSO-containing wastewater treatment method and treatment apparatus of the present invention, it is possible to recover DMS purified from DMSO-containing wastewater, suppress the generation of odorous gas due to decomposition of DMS, and an anaerobic treatment tank; By providing the aerobic treatment tank, an excellent effect can be obtained as a treatment method that can also treat wastewater containing organic matter other than DMSO. Further, since DMS is almost removed in the anaerobic treatment tank, it is possible to achieve reduction of aeration energy and reduction of generated excess sludge in the aerobic treatment tank.

Hereinafter, embodiments of the treatment apparatus and treatment method for DMSO-containing water of the present invention will be described. The treatment apparatus and treatment method for DMSO-containing water of the present invention are not limited to the following embodiments.

(Embodiment 1)
FIG. 2 is a schematic configuration diagram of a DMSO-containing water treatment apparatus 100 according to an embodiment of the present invention. The DMSO-containing water wastewater treatment apparatus 100 according to the first embodiment includes a decomposition and mixing tank 101, an aerobic treatment tank 111, a solid-liquid separation tank 121, and a DMS recovery apparatus 131, which are anaerobic treatment tanks.

The decomposition / mixing tank 101 has an aeration tube 103. In addition, a pipe 141 for supplying DMSO-containing waste water and pipes 142, 145 a and 146 are connected to the decomposition and mixing tank 101.

The aerobic treatment tank 111 has an aeration tube 113. In addition, pipes 142, 143 and 145b are connected to the aerobic treatment tank 111.

Pipes 143, 144 and 145 are connected to the solid-liquid separation tank 121.

Pipes 146, 147 and 148 are connected to the DMS recovery device 131.

Hereinafter, the detail of the processing apparatus 100 for DMSO containing water which concerns on one Embodiment of this invention is demonstrated.

An organic matter-containing wastewater containing DMSO is fed from the pipe 141 to the decomposition and mixing tank 101 and mixed with aerobic bacteria and facultative anaerobic bacteria, or aerobic bacteria or facultative anaerobic bacteria. Examples of the mixing method include stirring with a gas not containing oxygen or mechanical stirring.

Examples of the gas not containing oxygen include nitrogen gas and argon gas. In one embodiment of the present invention, stirring using nitrogen gas is performed, but the present invention is not limited thereto.

In the presence of aerobic bacteria or facultative anaerobic bacteria, DMSO is subjected to anaerobic biological treatment in the decomposition mixing tank 101 and decomposed into DMS. At this time, the reduction reaction from DMSO to DMS is considered to proceed promptly, with the organic matter in the wastewater serving as the hydrogen supply source.

・・・（１）

・・・（２） At this time, for example, when ethanol is used as the organic substance, it is considered that the reactions of the chemical reaction formulas (1) and (2) have occurred.

... (1)

... (2)

The generated DMS is vaporized by contact with the gas supplied from the diffusing tube 103 and is recovered by the DMS recovery device 131 through the pipe 146. At this time, the organic matter-containing wastewater containing DMS may be sprinkled in the decomposition and mixing tank 101.

Further, as a method for separating the produced DMS into the gas phase, in addition to the method for contacting with the gas, for example, by containing the organic matter containing DMS by reducing the pressure in the decomposition and mixing tank 101 using a decompression means such as a vacuum pump. A method may be used in which DMS is separated from the wastewater by transferring it to the gas phase.

Examples of the DMS recovery device include a heat exchanger or an adsorption tower. When a heat exchanger is used, it is liquefied by cooling to the boiling point (37.5 ° C.) or lower of DMS and recovered from the pipe 148. Examples of the adsorbent packed in the adsorption tower according to an embodiment of the present invention include porous silica or activated carbon treated with nitric acid. The DMS recovery method of the present invention is not limited to these.

When DMS is recovered by an adsorption method using an adsorption tower, an appropriate solvent is introduced into the DMS recovery device 131 as an eluent from the pipe 147, and DMS is eluted from the adsorbent and recovered from the pipe 148. DMS is concentrated and purified through the adsorption and elution steps.

Examples of the solvent for eluting DMS using an adsorption tower include DMSO and paraffinic hydrocarbons. As a solvent for eluting DMS according to an embodiment of the present invention, DMSO is particularly preferable, but is not limited thereto.

The DMS-containing solution recovered by the DMS recovery device 131 can be delivered to a DMSO manufacturer, or DMSO can be synthesized using the recovered DMS as a raw material. DMSO can be synthesized from DMS by adding nitrogen oxides as a catalyst to the DMS-containing solution recovered by elution with DMSO (GA A. Wetterholm and K. R. Fossan, U.S.). Pat. 2, 702, 824 Feb. 22 1955). In addition, an apparatus using the DMSO synthesis method may be connected to the DMS recovery apparatus 131 according to an embodiment of the present invention.

The organic matter-containing wastewater from which DMS is separated is sent to the aerobic treatment tank 111 through a pipe 142. The fed organic matter-containing wastewater is aerated by the air diffuser 113, and the remaining organic matter is aerobically biologically treated with aerobic activated sludge. The remaining organic substances are organic substances mainly used as a hydrogen supply source in the anaerobic biological treatment, and there are other DMS that have not been vaporized.

Examples of the aerobic treatment tank include a complete mixing system of activated sludge or a contact aeration system in which a filler is installed inside the tank. The aerobic treatment tank may be one tank or a plurality of layers connected in series.

The organic matter-containing wastewater that has been subjected to the aerobic biological treatment in the aerobic treatment tank 111 is sent to the solid-liquid separation tank 121 through the pipe 143 and separated into solid and liquid. Examples of the solid-liquid separation tank include a precipitation tank and a dehydrator. In one embodiment of the present invention, it is particularly preferable to use a precipitation tank.

The supernatant water separated in the solid-liquid separation tank 121 is discharged out of the system from the pipe 144 as treated water. In addition, the solid-liquid separated sludge is extracted through the pipe 145, returned to the decomposition and mixing tank 101 through the pipe 145a, and returned to the aerobic treatment tank 111 through the pipe 145b. The returned sludge is subjected to anaerobic biological treatment and aerobic biological treatment again. If necessary, a part of the sludge separated into solid and liquid is discharged out of the system.

Since the returned sludge is aerobically treated in the aerobic treatment tank 111, absolute anaerobic bacteria such as sulfate-reducing bacteria are not mixed therein. For this reason, in the decomposition and mixing tank 101, generation of odorous gases such as methyl mercaptan and hydrogen sulfide, which are decomposition intermediates of DMS, due to contamination with sulfate-reducing bacteria and the like can be avoided.

As described above, in the DMSO-containing wastewater treatment apparatus and treatment method of the present invention according to the present embodiment, purified DMS can be recovered, the generation of odorous gas due to decomposition of DMS is suppressed, and anaerobic By providing the treatment tank and the aerobic treatment tank, an excellent effect can be obtained as a treatment method that can also treat organic matter-containing wastewater other than DMSO. Moreover, since DMS is almost removed in the anaerobic treatment tank, it is an excellent DMSO-containing wastewater treatment apparatus and treatment method that leads to reduction of aeration energy in the aerobic treatment tank and reduction of generated excess sludge.

(Embodiment 2)
FIG. 3 is a schematic configuration diagram of a DMSO-containing water treatment apparatus 200 according to Embodiment 2 of the present invention. A DMSO-containing water wastewater treatment apparatus 200 according to Embodiment 2 of the present invention includes a decomposition and mixing tank 201, an aerobic treatment tank 111, a solid-liquid separation tank 121, a DMS recovery apparatus 131, and a gas-liquid separation that are anaerobic treatment tanks. A tank 211 is provided. Note that the same components as those in the first embodiment will be described using the same reference numerals.

A pipe 221 for supplying DMSO-containing waste water and pipes 222 and 145a are connected to the decomposition and mixing tank 201.

The gas-liquid separation tank 211 has a water spray tube 213 and a gas diffuser tube 215. Further, pipes 222, 223 and 224 are connected to the gas-liquid separation tank 211.

The aerobic treatment tank 111 has an aeration tube 113. The aerobic treatment tank 111 is connected with a pipe 223 and 143 and 145b.

Pipes 143, 144 and 145 are connected to the solid-liquid separation tank 121.

Pipes 224, 147 and 148 are connected to the DMS recovery device 131.

Hereinafter, details of the DMSO-containing water treatment apparatus 200 according to an embodiment of the present invention will be described.

An organic matter-containing wastewater containing DMSO is fed from the pipe 221 to the decomposition and mixing tank 201 and mixed with aerobic bacteria and facultative anaerobic bacteria, or aerobic bacteria or facultative anaerobic bacteria. As the mixing method, there is the method described in the first embodiment, and any of the mixing methods of the present invention according to this embodiment may be used.

In the decomposition mixing tank 201 in the presence of aerobic bacteria or facultative anaerobic bacteria, the organic matter is subjected to anaerobic biological treatment, and DMSO is decomposed into DMS. The generated organic matter-containing wastewater containing DMS is sent to the gas-liquid separation tank 211 through the pipe 222.

In the gas-liquid separation tank 201, for example, the inside of the gas-liquid separation tank is decompressed using a decompression means such as a vacuum pump, thereby separating the DMS from the organic matter-containing wastewater containing DMS transferred to the gas phase. For example, a method or a method of vaporizing DMS by spraying the organic substance-containing wastewater containing DMS fed from the water spray pipe 213 and contacting with the oxygen-free gas supplied from the air diffuser pipe 215 is used. The vaporized DMS is recovered by the DMS recovery device 131 through the pipe 224. The gas-liquid separation method of DMS in the present invention of the present embodiment is not limited to these.

Examples of the gas not containing oxygen include nitrogen gas and argon gas as described in the first embodiment. In one embodiment of the present invention, aeration using nitrogen gas is performed, but the present invention is not limited thereto.

The vaporized DMS is sent to the DMS recovery unit 131 through the pipe 224, and the organic substance-containing waste water from which the DMS is separated is sent to the aerobic treatment tank 111 through the pipe 223. The subsequent processing in the DMS recovery device 131, the processing in the aerobic processing tank 111, the processing in the solid-liquid separation tank 121, the sludge return processing to the decomposition and mixing tank 201 and the sludge return processing to the aerobic processing tank 111 are carried out. Since it is the same as that of the processing apparatus 100 of this invention which concerns on form 1, description is abbreviate | omitted here.

As described above, in the DMSO-containing wastewater treatment apparatus and treatment method of the present invention according to the present embodiment, by providing a gas-liquid separation tank separately from the decomposition and mixing tank, contact between the gas not containing oxygen and the DMS-containing wastewater is achieved. Increased efficiency enables efficient recovery of purified DMS, suppresses generation of odorous gas due to decomposition of DMS, and includes an anaerobic treatment tank and an aerobic treatment tank As a treatment method capable of treating wastewater containing organic matter other than DMSO, it has an excellent effect. Moreover, since DMS is almost removed in the anaerobic treatment tank, it is an excellent DMSO-containing wastewater treatment apparatus and treatment method that leads to reduction of aeration energy in the aerobic treatment tank and reduction of generated excess sludge.

(Embodiment 3)
FIG. 4 is a schematic configuration diagram of a DMSO-containing water treatment apparatus 300 according to an embodiment of the present invention. A DMSO-containing water wastewater treatment apparatus 300 according to Embodiment 3 of the present invention includes a decomposition and mixing tank 301, an aerobic treatment tank 111, a solid-liquid separation tank 121, a DMS recovery apparatus 131, and a decomposition and mixing apparatus that are anaerobic treatment tanks. A pipe 312 for introducing an organic substance into the tank 301 is included. Note that the same components as those in the first embodiment will be described using the same reference numerals.

The decomposition / mixing tank 301 has an aeration tube 303. In addition, a pipe 311 and pipes 312, 313, 314 and 145 a for supplying DMSO-containing waste water are connected to the decomposition and mixing tank 301.

The aerobic treatment tank 111 has an aeration tube 113. In addition, pipes 313, 143, and 145b are connected to the aerobic treatment tank 111.

Pipes 143, 144 and 145 are connected to the solid-liquid separation tank 121.

Pipes 314, 147 and 148 are connected to the DMS recovery device 131.

Details of the DMSO-containing water treatment apparatus 300 according to an embodiment of the present invention will be described below.

DMSO-containing wastewater is supplied to the decomposition / mixing tank 301 from the pipe 311, and organic substances for promoting the anaerobic biological treatment of DMSO are introduced to the decomposition / mixing tank 301 from the pipe 312, and aerobic bacteria and facultative anaerobic are introduced. Mix with bacteria or aerobic or facultative anaerobes.

In order to promote the anaerobic biological treatment of DMSO, the organic substance mixed with the DMSO-containing waste water is preferably an organic substance with good biodegradability. Examples of organic substances having good biodegradability include sugars, alcohols, and amines. Specifically, there are glucose, ethanol, and the like, and these can be introduced into the decomposition and mixing tank 301, or organic matter-containing wastewater such as isopropyl alcohol and ethanol-containing cleaning wastewater can be introduced into the decomposition and mixing tank 301. The organic substance for promoting the anaerobic biological treatment of DMSO of the present invention is not limited to these.

Further, a pipe for introducing an organic substance for promoting anaerobic biological treatment of DMSO according to an embodiment of the present invention into the decomposition / mixing tank 301 is connected separately from a pipe for supplying DMSO-containing wastewater to the decomposition / mixing tank 301. However, a pipe for introducing an organic substance for promoting anaerobic biological treatment of DMSO may be connected to a pipe for feeding DMSO-containing wastewater to the decomposition and mixing tank 301. The method of introducing an organic substance for promoting the anaerobic biological treatment of DMSO of the present invention is not limited to these.

As a method for mixing DMSO-containing wastewater with organic matter, aerobic bacteria and facultative anaerobic bacteria, or aerobic bacteria or facultative anaerobic bacteria to promote anaerobic biological treatment of DMSO in the decomposition and mixing tank 301 There is the method described in Embodiment 1, and the stirring method using nitrogen gas is performed as the mixing method of the present invention according to this embodiment, but the present invention is not limited thereto.

In the presence of aerobic bacteria or facultative anaerobic bacteria, DMSO is subjected to anaerobic biological treatment in the decomposition mixing tank 301 and decomposed into DMS. At this time, in the reduction reaction from DMSO to DMS, organic substances for promoting anaerobic biological treatment of DMSO mixed with DMSO-containing wastewater serve as a hydrogen supply source, and the above chemical reaction formulas (1) and (2) It is considered that the reaction proceeds rapidly due to the reaction shown in.

As described in the first embodiment, the generated DMS vaporizes the DMS by depressurizing the decomposition / mixing tank 301 or bringing it into contact with a gas not containing oxygen supplied from the diffuser tube 303, and through the pipe 314, Recovered in the DMS recovery device 131. In the case where DMS is vaporized by contact with a gas not containing oxygen, organic matter-containing wastewater containing DMS may be sprinkled in the decomposition and mixing tank 301.

The organic matter-containing waste water from which DMS is separated is sent to the aerobic treatment tank 111 through a pipe 313. The subsequent processing in the DMS recovery device 131, the processing in the aerobic processing tank 111, the processing in the solid-liquid separation tank 121, the sludge return processing to the decomposition and mixing tank 301 and the sludge return processing to the aerobic processing tank 111 are carried out. Since it is the same as that of the processing apparatus 100 of this invention which concerns on form 1, description is abbreviate | omitted here.

As described above, in the DMSO-containing wastewater treatment apparatus and treatment method of the present invention according to the present embodiment, DMSO decomposition is performed by mixing DMSO-containing wastewater and organic matter for promoting anaerobic biological treatment of DMSO. The refined DMS can be recovered efficiently, the generation of odorous gas due to the decomposition of DMS is suppressed, and the anaerobic treatment tank and the aerobic treatment tank are provided. As a treatment method capable of treating wastewater containing organic matter other than DMSO, it has an excellent effect. Moreover, since DMS is almost removed in the anaerobic treatment tank, it is an excellent DMSO-containing wastewater treatment apparatus and treatment method that leads to reduction of aeration energy in the aerobic treatment tank and reduction of generated excess sludge.

(Embodiment 4)
FIG. 5 is a schematic configuration diagram of a DMSO-containing water treatment apparatus 400 according to an embodiment of the present invention. A DMSO-containing water wastewater treatment apparatus 400 according to Embodiment 4 of the present invention includes a decomposition and mixing tank 401, an aerobic treatment tank 111, a solid-liquid separation tank 121, a DMS recovery apparatus 131, and a gas-liquid separation that are anaerobic treatment tanks. The tank 211 includes a pipe 412 for introducing an organic substance into the decomposition and mixing tank 401. Note that the same configurations as those in Embodiments 1 and 2 will be described using the same reference numerals.

A pipe 411, pipes 412, 413, and 145a for supplying DMSO-containing wastewater are connected to the decomposition and mixing tank 401.

The gas-liquid separation tank 211 has a water spray tube 213 and a gas diffuser tube 215. Pipes 413, 223, and 224 are connected to the gas-liquid separation tank 211.

The aerobic treatment tank 111 has an aeration tube 113. In addition, pipes 223, 143, and 145 b are connected to the aerobic treatment tank 111.

Pipes 143, 144 and 145 are connected to the solid-liquid separation tank 121.

Pipes 224, 147 and 148 are connected to the DMS recovery device 131.

Hereinafter, details of the DMSO-containing water treatment apparatus 400 according to an embodiment of the present invention will be described.

DMSO-containing wastewater is supplied from the pipe 411 to the decomposition / mixing tank 401, and an organic substance for promoting the anaerobic biological treatment of DMSO is introduced to the decomposition / mixing tank 401 from the pipe 412 to aerobic bacteria and facultative anaerobic. Mix with bacteria or aerobic or facultative anaerobes.

In order to promote the anaerobic biological treatment of DMSO, as described in the third embodiment, the organic substance to be mixed with the DMSO-containing waste water is preferably an organic substance having good biodegradability.

In addition, as described in the third embodiment, the connection method of the pipe 412 for introducing the organic matter for promoting the anaerobic biological treatment of DMSO according to the embodiment of the present invention into the decomposition and mixing tank 401 is performed using DMSO-containing wastewater. Although it is connected separately from the pipe 411 that feeds the decomposition and mixing tank 401, DMSO-containing wastewater is fed to the decomposition and mixing tank 401 through a pipe 412 that introduces organic substances for promoting anaerobic biological treatment of DMSO. You may connect to the piping 411. The method of introducing an organic substance for promoting the anaerobic biological treatment of DMSO of the present invention is not limited to these.

As a mixing method of DMSO-containing wastewater and organic matter, aerobic bacteria and facultative anaerobic bacteria, or aerobic bacteria or facultative anaerobic bacteria for promoting anaerobic biological treatment of DMSO in the decomposition and mixing tank 401 There is the method described in the first embodiment, and any of the mixing methods of the present invention according to this embodiment may be used.

In the presence of aerobic bacteria or facultative anaerobic bacteria, DMSO is subjected to anaerobic biological treatment in the decomposition mixing tank 401 and decomposed into DMS. At this time, in the reduction reaction from DMSO to DMS, organic substances for promoting anaerobic biological treatment of DMSO mixed with DMSO-containing wastewater serve as a hydrogen supply source, and the above chemical reaction formulas (1) and (2) It is considered that the reaction proceeds rapidly due to the reaction shown in.

The organic matter-containing wastewater containing the decomposed DMS is sent to the gas-liquid separation tank 211 through the pipe 413. Subsequent processing in the gas-liquid separation tank 211, processing in the DMS recovery device 131, processing in the aerobic processing tank 111, processing in the solid-liquid separation tank 121, sludge return processing to the decomposition and mixing tank 401, and aerobic processing tank 111 Since the sludge returning process is the same as that of the processing apparatus 200 of the present invention according to the second embodiment, the description thereof is omitted here.

As described above, in the DMSO-containing wastewater treatment apparatus and treatment method of the present invention according to the present embodiment, DMSO-containing wastewater is decomposed by mixing DMSO-containing wastewater and organic matter for promoting anaerobic biological treatment of DMSO. In addition to the decomposition and mixing tank, by providing a gas-liquid separation tank, the contact efficiency between the oxygen-free gas and the DMS-containing wastewater is increased. Efficient recovery is possible, suppressing the generation of odorous gas due to the decomposition of DMS, and providing anaerobic treatment tank and aerobic treatment tank to treat wastewater containing organic matter other than DMSO As a processing method that can also be performed, it has an excellent effect. Moreover, since DMS is almost removed in the anaerobic treatment tank, it is an excellent DMSO-containing wastewater treatment apparatus and treatment method that leads to reduction of aeration energy in the aerobic treatment tank and reduction of generated excess sludge.

(Example)
Hereinafter, the example which processed DMSO content drainage according to the processing method of Embodiment 1 of the present invention is described in detail.

Table 1 is a table showing operating conditions and analysis results of each treatment tank in an example according to an embodiment of the present invention and in a comparative example.

2-aminoethanol (MEA) as an organic substance was added to and mixed with a DMSO solution dissolved at 300 mg / L in terms of TOC, so that the TOC concentration of the entire DMSO-containing synthetic waste water was 500 mg / L. In addition, DMSO-containing synthetic wastewater was prepared with a phosphate buffer so as to have a pH of 7.

The prepared DMSO-containing synthetic waste water was introduced into a 1 L DMSO decomposition / mixing tank 101 and mixed with surplus sludge from a municipal sewage treatment plant at a water temperature of 30 ° C. to perform anaerobic biological treatment. In this embodiment according to the present invention, since the DMSO decomposition and mixing tank 101 is small, DMSO-containing synthetic wastewater was mixed by aeration using nitrogen gas.

The exhaust gas containing vaporized DMS was introduced into a DMS recovery device 131 filled with silica, and DMS was adsorbed on silica as an adsorbent. DMS adsorbed on silica was recovered by eluting from silica using isooctane as the eluent.

As a result of analyzing the recovered eluent, it was found that about 2% of DMS was contained in the eluent, and that a conversion reaction from DMSO to DMS occurred in the DMSO decomposition mixing tank 101. Further, no other impurities were detected from the eluent.

The anaerobic biologically treated synthetic wastewater was aerobically biologically treated by sending water to a 2 L aerobic treatment tank 111 and aeration using surplus sludge from an urban sewage treatment plant as activated sludge. The treated water and exhaust gas after aerobic biological treatment were collected.

As a result of analyzing the recovered treated water and exhaust gas, the DMS concentration at the outlet of the DMSO decomposition mixing tank and the residual DMS concentration in the treated water of the aerobic activated sludge were below the lower limit of detection as shown in Table 1. Further, the DMS concentration in the exhaust gas from the aerobic treatment tank was also extremely low at 0.1 ppm or less.

(Comparative example)
The comparative example uses only one 5 liter aerobic treatment tank (aeration tank) without using the DMSO decomposition mixing tank, and performs the treatment with the TOC load and water temperature shown in Table 1, The treatment was performed under the same conditions as in the previous example.

As a result of analyzing the collected exhaust gas and treated water, as shown in Table 1, 7 to 20 mg / L of residual DMS was detected from the treated water. Further, the residual DMS concentration in the exhaust gas of the aerobic treatment tank was also as high as 10 to 60 pppm, and the odor caused by the DMS decomposition intermediate was intense.

As described above, in the DMSO-containing wastewater treatment method of the present invention according to this embodiment, DMS can be purified and recovered, generation of odorous gas due to decomposition of DMS is suppressed, and an anaerobic treatment tank is provided. By providing the aerobic treatment tank, an excellent effect can be obtained as a treatment method that can also treat wastewater containing organic matter other than DMSO. Moreover, since DMS is almost removed in the anaerobic treatment tank, it is an excellent DMSO-containing wastewater treatment apparatus and treatment method that leads to reduction of aeration energy in the aerobic treatment tank and reduction of generated excess sludge.

It is the figure which showed the biodegradation pathway of DMSO. It is a systematic diagram of the processing method 100 of DMSO containing water which concerns on one Embodiment of this invention. It is a systematic diagram of the processing method 200 of DMSO containing water which concerns on one Embodiment of this invention. It is a systematic diagram of the processing method 300 of DMSO containing water which concerns on one Embodiment of this invention. It is a systematic diagram of the processing method 400 of DMSO containing water which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Waste water treatment apparatus of Embodiment 101 Decomposition mixing tank 103 Aeration pipe 111 Aerobic treatment tank 113 Aeration pipe 121 Solid-liquid separation tank 131 DMS recovery apparatus 141 Piping 142 Piping 143 Piping 144 Piping 145 Piping 145a Piping 145b Piping 146 Piping 147 Piping 148 Piping 200 Wastewater treatment apparatus of Embodiment 2 201 Decomposition mixing tank 211 Gas-liquid separation tank 213 Sprinkling pipe 215 Diffusing pipe 221 Piping 222 Piping 223 Piping 224 Piping 300 Wastewater treatment apparatus of Embodiment 3 301 Decomposition mixing tank 303 Diffusing pipe 311 Piping 312 Piping 313 Piping 314 Piping 400 Waste water treatment apparatus 401 of embodiment 4 401 Decomposition mixing tank 401 Piping 412 Piping 413 Piping

Claims (15)

Anaerobic biological treatment of organic matter-containing wastewater containing dimethyl sulfoxide decomposes the organic matter other than dimethyl sulfoxide and produces methyl sulfide,
By vaporizing the produced methyl sulfide, the methyl sulfide is separated from the organic matter-containing waste water,
Aerobic biological treatment of the organic matter-containing wastewater from which the methyl sulfide has been separated;
Solid-liquid separation treatment of the organic matter-containing wastewater that has been aerobic biological treatment,
A method for treating organic matter-containing wastewater containing dimethyl sulfoxide, wherein at least part of the sludge subjected to the solid-liquid separation treatment is returned to the anaerobic biological treatment step and the aerobic biological treatment step. Mix organic matter other than dimethyl sulfoxide with organic matter-containing wastewater containing dimethyl sulfoxide,
Anaerobic biological treatment of the organic matter-containing wastewater decomposes the organic matter other than dimethyl sulfoxide and produces methyl sulfide,
By vaporizing the produced methyl sulfide, the methyl sulfide is separated from the organic matter-containing waste water,
Aerobic biological treatment of the organic matter-containing wastewater from which the methyl sulfide has been separated;
Solid-liquid separation treatment of the organic matter-containing wastewater that has been aerobic biological treatment,
A method for treating organic matter-containing wastewater containing dimethyl sulfoxide, wherein at least part of the sludge subjected to the solid-liquid separation treatment is returned to the anaerobic biological treatment step and the aerobic biological treatment step. 3. The methyl sulfide is separated from the organic matter-containing wastewater by aerating a gas not containing oxygen to the organic matter-containing wastewater and vaporizing the generated methyl sulfide. 4. A method for treating organic matter-containing wastewater containing dimethyl sulfoxide. The organic matter-containing wastewater containing the generated methyl sulfide is sprinkled, and the methyl sulfide is separated from the organic matter-containing wastewater by aerating an oxygen-free gas in an upward flow. A method for treating an organic matter-containing wastewater containing dimethyl sulfoxide according to 1 or 2. The method for treating organic matter-containing wastewater containing dimethylsulfoxide according to any one of claims 1 to 4, wherein the methyl sulfide separated from the organic matter-containing wastewater is recovered. 6. The treatment of wastewater containing organic matter containing dimethylsulfoxide according to claim 5, wherein the methyl sulfide separated from the wastewater containing organic matter is recovered by an adsorbent containing porous silica or activated carbon treated with nitric acid. Method. The method for treating wastewater containing organic matter according to claim 6, wherein a methyl sulfide-containing solution is obtained by bringing dimethyl sulfoxide or paraffinic hydrocarbon into contact with the adsorbent on which the methyl sulfide is adsorbed. By treating an organic matter-containing wastewater containing dimethyl sulfoxide with anaerobic biological treatment, the organic matter other than dimethyl sulfoxide is decomposed to produce methyl sulfide, and the produced methyl sulfide is vaporized to contain the methyl sulfide containing the organic matter. A first tank that separates from the waste water;
A second tank for aerobic biological treatment of the organic matter-containing wastewater from which the methyl sulfide has been separated;
A third tank for solid-liquid separation treatment of the organic matter-containing wastewater that has been subjected to the aerobic biological treatment;
A mechanism for returning at least a part of the solid-liquid separated sludge to the first tank and the second tank;
An apparatus for treating wastewater containing organic matter containing dimethyl sulfoxide, comprising: A first tank for decomposing the organic matter other than dimethyl sulfoxide and generating methyl sulfide by anaerobic biological treatment of wastewater containing organic matter containing dimethyl sulfoxide;
A fourth tank for separating the methyl sulfide from the organic matter-containing waste water by vaporizing the generated methyl sulfide;
A second tank for aerobic biological treatment of the organic matter-containing wastewater from which the methyl sulfide has been separated;
A third tank for solid-liquid separation treatment of the organic matter-containing wastewater that has been subjected to the aerobic biological treatment;
A mechanism for returning at least a part of the solid-liquid separated sludge to the first tank and the second tank;
An apparatus for treating wastewater containing organic matter containing dimethyl sulfoxide, comprising: Mix organic matter other than dimethyl sulfoxide with organic matter-containing wastewater containing dimethyl sulfoxide,
The organic matter-containing wastewater is subjected to anaerobic biological treatment to decompose the organic matter other than dimethylsulfoxide and produce methyl sulfide, and the produced methyl sulfide is vaporized to separate the methyl sulfide from the organic matter-containing wastewater. A first tank to
A second tank for aerobic biological treatment of the organic matter-containing wastewater from which the methyl sulfide has been separated;
A third tank for solid-liquid separation treatment of the organic matter-containing wastewater that has been subjected to the aerobic biological treatment;
A mechanism for returning at least a part of the solid-liquid separated sludge to the first tank and the second tank;
An apparatus for treating wastewater containing organic matter containing dimethyl sulfoxide, comprising: Mix organic matter other than dimethyl sulfoxide with organic matter-containing wastewater containing dimethyl sulfoxide,
A first tank that decomposes the organic matter other than dimethyl sulfoxide and produces methyl sulfide by anaerobically treating the organic matter-containing wastewater;
A fourth tank for separating the methyl sulfide from the organic matter-containing waste water by vaporizing the generated methyl sulfide;
A second tank for aerobic biological treatment of the organic matter-containing wastewater from which the methyl sulfide has been separated;
A third tank for solid-liquid separation treatment of the organic matter-containing wastewater that has been subjected to the aerobic biological treatment;
A mechanism for returning at least a part of the solid-liquid separated sludge to the first tank and the second tank;
An apparatus for treating wastewater containing organic matter containing dimethyl sulfoxide, comprising: 12. The methyl sulfide is separated from the organic matter-containing waste water by aerating a gas not containing oxygen to the organic matter-containing waste water and vaporizing the generated methyl sulfide. An apparatus for treating organic matter-containing wastewater containing dimethyl sulfoxide according to 1. The organic matter-containing wastewater containing the generated methyl sulfide is sprinkled, and the methyl sulfide is separated from the organic matter-containing wastewater by aerating an oxygen-free gas in an upward flow. The processing apparatus of the waste_water | drain containing organic substance containing the dimethyl sulfoxide as described in any one of 8 thru | or 11. The apparatus for treating wastewater containing organic matter according to any one of claims 8 to 13, further comprising a recovery device for recovering the methyl sulfide separated from the wastewater containing organic matter. The organic matter containing dimethyl sulfoxide according to claim 14, further comprising an adsorption device for recovering the methyl sulfide separated from the organic matter-containing wastewater by an adsorbent containing porous silica or activated carbon treated with nitric acid. Wastewater treatment equipment.

Images