CN110183029B

CN110183029B - Device and method for converting organic wastewater into acetic acid

Info

Publication number: CN110183029B
Application number: CN201910204025.6A
Authority: CN
Inventors: 蒋海明
Original assignee: Inner Mongolia University of Science and Technology
Current assignee: Inner Mongolia University of Science and Technology
Priority date: 2019-03-18
Filing date: 2019-03-18
Publication date: 2022-04-01
Anticipated expiration: 2039-03-18
Also published as: CN110183029A

Abstract

The invention discloses a device and a method for converting organic wastewater into acetic acid, wherein the device comprises a UASB reactor, a microbial electrolytic cell, an electrolytic cell and a power supply, wherein the power supply is used for applying voltage to the microbial electrolytic cell and the electrolytic cell; organic wastewater is converted into methane in a UASB reactor, and the methane is input into an electrolytic cell; the effluent of the UASB reactor enters a microbial electrolytic cell, organic matters in the effluent are converted into hydrogen under the action of electroactive microbes added in advance, and the hydrogen is input into the electrolytic cell; in the electrolytic cell, anthraquinone-2, 6-disulfonate or/and Fe in oxidation state³⁺For mediation, the introduced methane and hydrogen are converted into acetic acid under the action of electroactive anaerobic methanotrophic archaea and methanogens hydrogenophilous. The invention realizes the conversion of organic wastewater into acetic acid, not only treats the wastewater, but also obtains the chemical product acetic acid, provides a new way for effectively treating the organic wastewater, and has important significance for energy conservation, emission reduction and environmental management.

Description

Device and method for converting organic wastewater into acetic acid

Technical Field

The invention relates to a device and a method for converting organic wastewater into acetic acid, belonging to the technical field of resource utilization of organic wastewater and carbon dioxide.

Background

Energy, environment and water resources are the basis for human survival. With the rapid increase in the use of fossil fuels, particularly petroleum and natural gas, in recent years, a global energy crisis has been triggered. In addition, fossil fuels emit large amounts of CO during use₂Can cause greenhouse effect and cause warming of the climate. In addition, people generate a large amount of organic sewage in daily life and production processes. At present, the widely adopted sewage treatment technology is mainly aerobic biological treatment, wherein an activated sludge method is mainly used. However, the activated sludge process is energy-intensive for treating sewage, and at the same time, the activated sludge process also produces a large amount of sludge, which is also expensive to treat. The organic matters in the sewage are pollutants and contain energy at the same time, and can beAnd removing the waste water by resource utilization. How to convert carbon dioxide and organic wastewater into fuels and chemical products can solve environmental problems and realize sustainable development, which has become a problem that scientists in various countries in the world try to explore.

Acetic acid is an important chemical product, and has wide application in life and industrial production. At present, the acetic acid production methods mainly include an aerobic fermentation method, an anaerobic fermentation method, a microbial single-carbon synthesis method, a methanol carbonylation method, an acetaldehyde oxidation method and an ethylene oxidation method. The reaction principle of the aerobic fermentation method is C₂H₅OH+O₂→CH₃COOH+H₂O; the reaction principle of the anaerobic fermentation method is C₆H₁₂O₆→3CH₃COOH; the reaction principle of the microbial single carbon synthesis method is 2CO₂+4H₂→CH₃COOH+2 H₂O、2CO+2H₂→CH₃COOH; the reaction principle of the methanol carbonylation method is CH₃OH+CO→CH₃COOH; the reaction principle of the acetaldehyde oxidation method is 2CH₃CHO+O₂→2CH₃COOH。

The methods all have the defects of high treatment cost, need of noble metal catalysts, high energy consumption, poor environmental friendliness and the like.

Disclosure of Invention

The invention aims to provide a device and a method for converting organic wastewater into acetic acid, and the device and the method can be used for treating the organic wastewater and simultaneously obtaining a chemical product acetic acid, provide a new way for effectively treating the organic wastewater, and have important significance for energy conservation, emission reduction and environmental management.

The invention provides a device for converting organic wastewater into acetic acid, which mainly comprises a UASB reactor, a microbial electrolysis cell, an electrolysis cell and a power supply, wherein the power supply is used for applying voltage between the microbial electrolysis cell and the cathode and the anode of the electrolysis cell;

organic wastewater is converted into methane in a UASB reactor, and the methane is input into an electrolytic cell through a pipeline;

the effluent of the UASB reactor enters a microbial electrolytic cell, organic matters in the effluent are converted into hydrogen under the action of electroactive microbes added in advance, and the hydrogen is input into the electrolytic cell through a pipeline;

in the electrolytic cell, anthraquinone-2, 6-disulfonate or/and Fe in oxidation state³⁺For mediation, the introduced methane and hydrogen are converted into acetic acid under the action of electroactive anaerobic methanotrophic archaea and methanogens hydrogenophilous.

Furthermore, the UASB reactor is connected with a water inlet pipe, a blow-off pipe, a first exhaust pipe and a first water outlet pipe,

the microbial electrolysis cell is connected with a first water outlet pipe, a second exhaust pipe and a second water outlet pipe, namely, two ends of the first water outlet pipe are respectively connected with the UASB reactor and the microbial electrolysis cell;

the electrolytic cell is connected with an air inlet pipe and a third exhaust pipe;

the gas outlet ports of the first exhaust pipe and the second exhaust pipe are connected with the gas inlet port of the gas inlet pipe and used for leading the gas exhausted by the first exhaust pipe and the second exhaust pipe into the electrolytic cell.

Further, the anode electrode and the cathode electrode in the microbial electrolysis cell and the electrolysis cell are carbon cloth electrodes, particle graphite electrodes, reticular glass carbon electrodes, particle activated carbon electrodes or carbon fiber brush electrodes.

Preferably, the cathode electrode in the microbial electrolysis cell and the cathode electrode in the microbial electrolysis cell is a carbon cloth electrode, a particle graphite electrode, a net-shaped glassy carbon electrode, a particle activated carbon electrode or a carbon fiber brush electrode modified by a noble metal catalyst.

The invention provides a method for converting organic wastewater into acetic acid, which adopts the device and comprises the following steps:

(1) starting the UASB reactor:

anaerobic activated sludge of a sewage treatment plant is taken as an inoculum, primary sedimentation overflow liquid of the sewage treatment plant is taken as a culture medium, pure nitrogen is inoculated into a UASB reactor after being deoxidized, 37C constant-temperature culture is carried out, and when the UASB reactor continuously generates methane, the start of the UASB reactor is finished;

(2) starting the microbial electrolytic cell:

anaerobic activated sludge of a sewage treatment plant is taken as an inoculum, primary sedimentation overflow liquid of the sewage treatment plant is taken as a culture medium, pure nitrogen is used for removing oxygen to inoculate a microbial electrolytic cell, voltage is applied to the microbial electrolytic cell, constant-temperature culture is carried out at 37 ℃, 70% of liquid in the microbial electrolytic cell is replaced by fresh deoxygenated wastewater every 3-7 days, and when the current of the microbial electrolytic cell reaches the maximum and is stable, the starting of the microbial electrolytic cell is finished;

(3) the process for converting organic wastewater into acetic acid is carried out after starting up a UASB reactor and a microbial electrolytic cell:

continuously inputting the organic wastewater into a UASB reactor, and enabling methane generated in the UASB reactor to enter an electrolytic cell;

the effluent of the UASB reactor enters a microbial electrolysis cell, and H generated in the microbial electrolysis cell₂Entering an electrolytic cell;

a deoxygenation culture medium is filled in the electrolytic cell, and electroactive anaerobic methanotrophic archaea and hydrogenophilic methanogens are connected in the culture medium; in the electrolytic cell, anthraquinone-2, 6-disulfonate or/and Fe in oxidation state³⁺For mediation, the introduced methane and hydrogen are converted into acetic acid under the action of electroactive anaerobic methanotrophic archaea and methanogens hydrogenophilous.

Further, in the starting stage and the organic wastewater conversion stage, the microbial electrolysis cell and the cathode electrode potential in the microbial electrolysis cell are set to be-0.3V-2.0V. This potential is relative to the potential of a standard hydrogen electrode.

Further, the electroactive anaerobic methanotrophic archaea employs Methanosarcina acetivorans strain C2A.

The hydrogenophilic methanogen can be expressed as H₂And/or CO₂Is a nutritional methanogen. Further, methanogen hydrogenophilum is Methanococcus maripaludis.

Further, the culture Medium in the electrolytic cell is DSMZ Medium 141, and the components of the DSMZ Medium 141 are as follows:

KCl 0.34g/L；MgCl₂·6H₂O 4.00g/L；MgSO₄·7H₂O 3.45g/L；NH₄Cl 0.25g/L；CaCl₂·2H₂O 0.14g/L；K₂HPO₄0.49 g/L; NaCl 18.00 g/L; fe (0.1% by mass/volume)NH₄)₂(SO₄)·6H₂O solution is 2 mL/L; 3.20g/L of methanol; 3.40g/L of sodium formate; 2.00g/L of yeast extract; peptone 2.00 g/L; the mass volume concentration of the resazurin solution is 0.1 percent, and the concentration of the resazurin solution is 0.50 mL/L; NaHCO 2₃5.00 g/L; 10mL/L of trace element solution; trace vitamin is 10.00 mL/L; 0.50g/L of monohydrate L-cysteine hydrochloride; na (Na)₂S·9H₂O0.50 g/L; 1000.00mL/L deionized water;

wherein, the microelement solution comprises the following components: nitrilotriacetic acid 1.5g/L, MgSO₄·7H₂O 3.0g/L，MnSO₄·H₂O 0.5g/L， NaCl 1.0g/L，FeSO₄·7H₂O 0.1g/L，CoCl₂·6H₂O 0.1g/L，CaCl₂ 0.1g/L，ZnSO₄·7H₂O 0.1g/L， CuSO₄·5H₂O 0.01g/L，AlK(SO₄)₂·12H₂O 0.01g/L，H₃BO₃ 0.01g/L，Na₂MoO₄·2H₂0.01g/L of O and 1.0L/L of deionized water;

the trace element solution comprises the following components: 2.0mg/L of biotin, 2.0mg/L of folic acid, 10.0mg/L of vitamin B6 hydrochloride, 5.0mg/L of thiamine hydrochloride, 5.0mg/L of vitamin B25.0 mg/L, 5.0mg/L of nicotinic acid, 5.0mg/L of D-calcium pantothenate, 5.0mg/L of vitamin B120.1 mg/L, 5.0mg/L of p-aminobenzoic acid, 5.0mg/L of lipoic acid and 1.0L/L of deionized water.

Further, the organic wastewater is domestic sewage, food processing wastewater, starch processing wastewater or beer production wastewater.

The principle of converting organic wastewater into acetic acid is as follows:

firstly, converting organic wastewater into methane by using a UASB reactor, and feeding the generated methane into an electrolytic cell; the effluent of the UASB reactor enters a microbial electrolysis cell, organic matters in the effluent are converted into hydrogen by the microbial electrolysis cell, and the generated hydrogen enters the electrolysis cell. Organic wastewater is treated in a UASB reactor and a microbial electrolysis cell, and raw material gases of methane and hydrogen for producing acetic acid are obtained. Anthraquinone-2, 6-disulfonate (AQDS) or/and Fe in the oxidation state in an electrolytic cell³⁺For mediation, methane and hydrogen are used for electrically activating anaerobic methane-nourishing archaeaAnd methanogen in the presence of hydrogen, thereby realizing the treatment of organic wastewater and the production of acetic acid.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the method realizes the conversion of the organic wastewater into the acetic acid, not only treats the wastewater, but also obtains the chemical product acetic acid, provides a new way for effectively treating the organic wastewater, and has important significance for energy conservation, emission reduction and environmental management.

(2) The electrode of the invention does not need to use expensive catalyst, has low cost and low energy consumption, and has faster organic sewage treatment and acetic acid generation rate.

Drawings

FIG. 1 is a schematic diagram of an example apparatus.

In the figure, 1-a water inlet pipe, 2-a UASB reactor, 3-a sewage discharge pipe, 4-a valve, 5-a first exhaust pipe, 6-an air inlet pipe, 7-a first water outlet pipe, 8-a microbial electrolysis cell, 9-a first anode electrode, 10-a first titanium wire lead, 11-a first cathode electrode, 12-a second titanium wire lead, 13-a second exhaust pipe, 14-a second water outlet pipe, 15-an electrolysis cell, 16-a second anode electrode, 17-a third titanium wire lead, 18-a second cathode electrode, 19-a fourth titanium wire lead, 20-a third exhaust pipe and 21-a solar power supply.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example 1

This example is an apparatus for converting organic waste water into acetic acid. Referring to fig. 1, which is a schematic view of the apparatus of the present embodiment, the apparatus mainly includes a UASB reactor (i.e., upflow anaerobic reactor) 2, a microbial cell 8, an electrolytic cell 15, and a solar power supply 21, and the solar power supply 21 is used to apply a voltage to the microbial cell 8 and the electrolytic cell 15. The UASB reactor 2, the microbial electrolysis cell 8 and the electrolysis cell 15 are all closed containers, and are passed through the closed containersThe connected connecting pipe is communicated with the outside. The organic wastewater is fed into the UASB reactor 2 and subjected to anaerobic digestion to generate methane, and the generated methane is fed into the electrolytic cell 15. The effluent of the UASB reactor enters a microbial electrolysis cell 8, the microbial electrolysis cell 8 utilizes the electric active microbes added in advance as a reaction main body to generate hydrogen through reaction, and the generated hydrogen is input into an electrolysis cell 15. In the electrolytic cell 15, anthraquinone-2, 6-disulfonate or/and Fe in the oxidized state³⁺For mediation, the introduced methane and hydrogen are converted into acetic acid under the action of electroactive anaerobic methanotrophic archaea and methanogens hydrogenophilous.

Specifically, the UASB reactor 2 is connected with a water inlet pipe 1, a blow-off pipe 3, a first exhaust pipe 5 and a first water outlet pipe 7. Specifically, a water inlet pipe 1 is connected with the lower part of a UASB reactor 2 and is used for introducing organic wastewater; a sewage discharge pipe 3 is connected with the bottom end of the UASB reactor 2, a valve 4 is arranged on the sewage discharge pipe 3, and the sludge can be discharged from the bottom end of the UASB reactor 2 by opening the valve 4; the first exhaust pipe 5 is connected with the top end of the UASB reactor 2, and the first water outlet pipe 7 is connected with the upper part of the UASB reactor 2.

Specifically, the microbial electrolysis cell 8 is provided with a first anode electrode 9 and a first cathode electrode 11, and the first anode electrode 9 and the first cathode electrode 11 are connected to a high potential end and a low potential end of an external solar power supply 21 through a first titanium wire lead 10 and a second titanium wire lead 12, respectively. The microbial electrolysis cell 8 is also connected with a first water outlet pipe 7, a second exhaust pipe 13 and a second water outlet pipe 14. The first water outlet pipe 7 is connected with the lower part of the microbial electrolytic cell 8, namely, two ends of the first water outlet pipe 7 are respectively connected with the UASB reactor 2 and the microbial electrolytic cell 8; the second exhaust pipe 13 is connected with the top end of the microbial electrolysis cell 8, and the second water outlet pipe 14 is connected with the upper part of the microbial electrolysis cell 8.

Specifically, the electrolytic cell 15 is provided with a second anode electrode 16 and a second cathode electrode 18, and the second anode electrode 16 and the second cathode electrode 18 are connected to a high potential terminal and a low potential terminal of an external solar power supply 21 through a third titanium wire 17 and a fourth titanium wire 19, respectively. The electrolytic cell 15 is also connected with an air inlet pipe 6 and a third exhaust pipe 20. Specifically, the inlet pipe 6 has a nozzle extending into the electrolytic cell 15, and the third exhaust pipe 20 is connected to the top end of the electrolytic cell 15.

In the present invention, the first exhaust pipe 5, the second exhaust pipe 13, and the intake pipe 6 are communicated with each other, and specifically, the outlet ports of the first exhaust pipe 5 and the second exhaust pipe 13 are connected to the inlet port of the intake pipe 6, and are used to introduce the gas discharged from the first exhaust pipe 5 and the second exhaust pipe 13 into the electrolytic cell 15.

In this embodiment, the UASB reactor 2, the microbial electrolysis cell 8, and the electrolysis cell 15 are made of organic glass, all the connection pipes are silicone tubes, the first anode electrode 9, the first cathode electrode 11, the second anode electrode 16, and the second cathode electrode 18 may be carbon cloth, graphite particles, reticulated vitreous carbon, activated carbon particles, or carbon fiber brush electrodes, and the first cathode electrode 11 and the second cathode electrode 18 may also be modified with catalysts such as Pt.

Example 2

The embodiment of the method for converting organic wastewater into acetic acid is realized by adopting the device in the embodiment 1, and the method comprises the following steps:

(1) starting up UASB reactor and microbial electrolysis cell

(1a) Starting up UASB reactor

Anaerobic activated sludge of a sewage treatment plant is taken as an inoculum, primary sedimentation overflow liquid of the sewage treatment plant is taken as a culture medium, pure nitrogen is inoculated into a UASB reactor according to the proportion of 3:7(v/v) after being deoxidized, wherein 3:7(v/v) specifically means that the volume ratio of the anaerobic activated sludge and the primary sedimentation overflow liquid which are inoculated into the UASB reactor is 3: 7. 37C, and finishing the startup of the UASB reactor when the UASB reactor can continuously produce methane.

(1b) Starting microbial electrolysis cell

Anaerobic activated sludge of a sewage treatment plant is taken as an inoculum, primary sedimentation overflow liquid of the sewage treatment plant is taken as a culture medium, a microorganism electrolytic tank is inoculated at a ratio of 2:8(v/v) after pure nitrogen removes oxygen, wherein 2:8(v/v) specifically means that the volume ratio of the anaerobic activated sludge and the primary sedimentation overflow liquid which are inoculated into a UASB reactor is 2: 8. The external voltage of the microbial electrolytic cell is fixed to-0.9V, and the microbial electrolytic cell is cultured at the constant temperature of 37C. The current of the microbial electrolysis cell and the composition of the gas at the upper part of the microbial electrolysis cell are measured every day. The microbial electrolytic cell is operated in batches, 70% of liquid is replaced by fresh deoxygenated wastewater every 5 days, and the microbial electrolytic cell is started after the current of the microbial electrolytic cell is maximum and stable.

(2) Culture of electrically active anaerobic methane-nourishing archaea and methanogen

In this example, methanotrophic archaea using Methanosarcina acetovorans strain C2A and methanogenic bacteria using Methanococcus maripaludis were used as the electroactive anaerobic methanotrophic archaea.

(2a) Cultivation of Methanosarcina acetovorans strain C2A

Methanosarcina acetovorans strain C2A was cultured in DSMZ Medium 141 Medium. The Medium of DSMZ Medium 141 comprises KCl 0.34 g/L; MgCl₂·6H₂O 4.00g/L；MgSO₄·7H₂O 3.45g/L；NH₄Cl 0.25 g/L；CaCl₂·2H₂O 0.14g/L；K₂HPO₄ 0.49g/L；NaCl 18.00g/L；Fe(NH₄)₂(SO₄)·6H₂O solution (0.1% W/V)2 mL/L; 3.20g/L of methanol; 2.00g/L of yeast extract; peptone 2.00 g/L; resazurin solution (0.1% W/V)0.50 mL/L; NaHCO 2₃5.00 g/L; 10mL/L of trace element solution; trace vitamin is 10.00 mL/L; 0.50g/L of monohydrate L-cysteine hydrochloride; na (Na)₂S·9H₂O0.50 g/L; 1000.00mL/L deionized water. The trace element solution comprises the following components: nitrilotriacetic acid 1.5g/L, MgSO₄·7H₂O 3.0g/L，MnSO₄·H₂O 0.5g/L，NaCl 1.0g/L，FeSO₄·7H₂O 0.1g/L，CoCl₂·6H₂O 0.1g/L，CaCl₂ 0.1g/L，ZnSO₄·7H₂O 0.1g/L， CuSO₄·5H₂O 0.01g/L，AlK(SO₄)₂·12H₂O 0.01g/L，H₃BO₃ 0.01g/L，Na₂MoO₄·2H₂O0.01 g/L and deionized water 1.0L/L. The trace element solution comprises the following components: 2.0mg/L of biotin, 2.0mg/L of folic acid, 10.0mg/L of vitamin B6 hydrochloride, 5.0mg/L of thiamine hydrochloride, 5.0mg/L of vitamin B25.0 mg/L, 5.0mg/L of nicotinic acid, 5.0mg/L of D-calcium pantothenate, 5.0mg/L of vitamin B120.1 mg/L, 5.0mg/L of p-aminobenzoic acid, 5.0mg/L of lipoic acid and 1.0L/L of deionized water.

The preparation method of the DSMZ Medium 141 culture Medium comprises the following steps:

dissolving the above materials except bicarbonate, vitamins, cysteine, and sulfide in 1000.00mL deionized water, boiling, and placing in ice bath with N₂And CO₂The mixed gas is aerated and cooled to room temperature, and N in the mixed gas₂And CO of₂Is 8: 2. then subpackaging the mixture into 250mL anaerobic bottles, wherein the liquid filling amount in the anaerobic bottles is 150 mL; then N is added₂And CO₂Aerating the mixed gas for 30-45 min to make it anaerobic, sealing, sterilizing at 121 deg.C for 30 min, and cooling to room temperature. After sterilization, adding deoxidized bicarbonate to dissolve, and adjusting the pH to 7.0; adding sterilized and deoxidized cysteine and sodium sulfide solution to make the final concentration of cysteine and sodium sulfide reach 0.50 g/L; adding filtered sterilized and deoxygenated vitamin solution to make its final concentration reach 10.00 mL/L.

The method for culturing Methanosarcina acetivorans strain C2A comprises the following steps: methanosarcina acet ivorans strain C2A was inoculated at 10% (V/V) into an anaerobic flask and cultured at 37 ℃.

(2b) Cultivation of Methanococcus maribauris

Methanococcus maripaludis was also cultured in DSMZ Medium 141 Medium. The Medium composition of the DSMZ Medium 141 is as follows: KCl is 0.34 g/L; MgCl₂·6H₂O 4.00g/L；MgSO₄·7H₂O 3.45g/L；NH₄Cl 0.25 g/L；CaCl₂·2H₂O 0.14g/L；K₂HPO₄ 0.49g/L；NaCl 18.00g/L；Fe(NH₄)₂(SO₄)·6H₂2mL/L of O solution (0.1%/V); 3.40g/L of sodium formate; 2.00g/L of yeast extract; peptone 2.00 g/L; resazurin solution (0.1% W/V)0.50 mL/L; NaHCO 2₃5.00 g/L; 10mL/L of trace element solution; trace vitamin is 10.00 mL/L; 0.50g/L of monohydrate L-cysteine hydrochloride; na (Na)₂S·9H₂O0.50 g/L; 1000.00mL/L deionized water. The composition of the trace element solution is as follows: nitrilotriacetic acid 1.5g/L, MgSO₄·7H₂O 3.0g/L，MnSO₄·H₂O 0.5g/L，NaCl 1.0 g/L，FeSO₄·7H₂O 0.1g/L，CoCl₂·6H₂O 0.1g/L，CaCl₂ 0.1g/L，ZnSO₄·7H₂O 0.1g/L， CuSO₄·5H₂O 0.01g/L，AlK(SO₄)₂·12H₂O 0.01g/L，H₃BO₃ 0.01g/L，Na₂MoO₄·2H₂O0.01 g/L and deionized water 1.0L/L. The composition of the trace element solution is as follows: 2.0mg/L of biotin, 2.0mg/L of folic acid, 10.0mg/L of vitamin B6 hydrochloride, 5.0mg/L of thiamine hydrochloride, 5.0mg/L of vitamin B25.0 mg/L, 5.0mg/L of nicotinic acid, 5.0mg/L of D-calcium pantothenate, 5.0mg/L of vitamin B120.1 mg/L, 5.0mg/L of p-aminobenzoic acid, 5.0mg/L of lipoic acid and 1.0L/L of deionized water.

dissolving the above materials except bicarbonate, vitamins, cysteine, and sulfide in 1000.00mL deionized water, boiling, and placing in ice bath with N₂And CO₂The mixed gas is aerated and cooled to room temperature, and N in the mixed gas₂And CO of₂Is 8: 2. then subpackaging the mixture into 250mL anaerobic bottles, wherein the liquid filling amount in the anaerobic bottles is 150 mL; then N is added₂And CO₂Aerating the mixed gas for 30-45 minutes to ensure that the mixed gas is anaerobic, then sealing the mixed gas by a gland, sterilizing the mixed gas for 30 minutes at 121 ℃, and cooling the mixed gas to room temperature. After sterilization, adding deoxidized bicarbonate to dissolve, and adjusting the pH to 6.8; adding sterilized and deoxidized cysteine and sodium sulfide solution to make the final concentration of cysteine and sodium sulfide reach 0.50 g/L; adding filtered sterilized and deoxygenated vitamin solution to make its final concentration reach 10.00 mL/L.

The method for culturing Methanococcus maripluris comprises the following steps: sterile H for media in anaerobic flasks₂And CO₂Aerating the mixed gas for 30-45 minutes, wherein H in the mixed gas₂And CO of₂Is 8: 2; make H₂And CO₂The mixture was maintained at two atmospheres, and then Methanococcus maripluris was introduced into an anaerobic flask at 10% (V/V) and cultured at 37 ℃.

(3) Process for converting organic wastewater into acetic acid

UASB reactor 2 and microorganismsAfter the electrolytic cell 8 is started, the organic wastewater is continuously input into the UASB reactor 2 through the water inlet pipe 1. The organic wastewater is suitable for the growth of microorganisms and comprises domestic wastewater, food processing wastewater, starch processing wastewater or beer production wastewater and the like. Anaerobic digestion of organic wastewater in UASB reactor 2 to produce methane CH₄，CH₄The gas enters the electrolytic cell 15 through the first exhaust pipe 5 and the gas inlet pipe 6 in sequence, and the cultured Methanococcus maritimas strain C2A and Methanococcus maritimaudis added in advance in the electrolytic cell 15.

The effluent of the UASB reactor 2 enters a microbial electrolysis cell 8 through a first water outlet pipe 7, and the electroactive microbes adsorbed on the surface of a first anode electrode 9 in the microbial electrolysis cell 8 generate CO by using organic matters in the effluent as substrates₂、H⁺And electrons, H⁺And electrons are transferred to the first cathode electrode 11 under the action of an applied voltage, and H is generated on the surface of the first cathode electrode 11₂(ii) a Generation of H₂And enters the electrolytic cell 15 through the second exhaust pipe 13 and the air inlet pipe 6 in sequence.

Methanococcus maribaudianis in electrolytic cell 15₂And CO₂Conversion to CH₄While Methanosarcina acetovorans strain C2A in the electrolytic cell 15 is in the oxidation state anthraquinone-2, 6 disulfonate (AQDS), Fe³⁺Mediated conversion of methane to acetic acid and H⁺Simultaneously produce reduced quinone-2, 6 disulfonate (AQDSH)₂) And Fe²⁺，AQDSH₂And Fe²⁺Is oxidized on the surface of the second anode electrode 16 of the electrolytic cell 15 to generate electrons, and generate H⁺And electrons migrate to the second cathode electrode 18 under the action of an applied voltage and generate H on the surface of the second cathode electrode 18₂Generation of H₂And converted into CH by Methanococcus maripaludis₄，CH₄And converted into acetic acid by Methanosarcina acetovorans strain C2A. The acetic acid can be continuously generated by the circular reaction. Through detection, the conversion rate of converting organic matters in the organic wastewater into the acetic acid reaches more than 60 percent by adopting the device.

The following reactions are involved in the UASB reactor:

the anode electrode in the microbial electrolysis cell 8 is involved in the reaction:

the cathode electrode in the microbial electrolysis cell 8 is involved in the reaction:

2H⁺+2e^-→H₂

the following reactions are involved in the cell 15:

the anode electrode in the electrolytic cell 15 is involved in the reaction:

AQDSH₂→AQDS+2H⁺+2e^-

Fe^2-→Fe³⁺+e^-

the cathode electrode in the electrolytic cell 15 is involved in the reaction:

2H⁺+2e^-→H₂

the above-described embodiment is only one of many embodiments, and those skilled in the art can make other variations or modifications on the basis of the above description, and such other variations or modifications may be made without departing from the spirit of the present invention.

Claims

1. An apparatus for converting organic wastewater into acetic acid, which is characterized in that:

mainly comprises a UASB reactor, a microbial electrolytic cell, an electrolytic cell and a solar power supply, wherein the solar power supply is used for applying voltage between the microbial electrolytic cell and the cathode and the anode of the electrolytic cell;

in the electrolytic cell, anthraquinone-2, 6-disulfonate and Fe are present in the oxidation state³⁺For mediation, the introduced methane and hydrogen are converted into acetic acid under the action of electroactive anaerobic methanotrophic archaea and methanogens hydrogenophilous.

2. The apparatus of claim 1, wherein:

the UASB reactor is connected with a water inlet pipe, a blow-off pipe, a first exhaust pipe and a first water outlet pipe,

3. The apparatus of claim 1, wherein:

the anode electrode and the cathode electrode in the microbial electrolysis cell and the electrolysis cell are carbon cloth electrodes, particle graphite electrodes, reticular glass carbon electrodes, particle activated carbon electrodes or carbon fiber brush electrodes.

4. The apparatus of claim 1, wherein:

the cathode electrodes of the microbial electrolysis cell and the electrolysis cell are carbon cloth electrodes, particle graphite electrodes, reticular glass carbon electrodes, particle activated carbon electrodes or carbon fiber brush electrodes modified by noble metal catalysts.

5. A method for converting organic wastewater into acetic acid is characterized in that:

the device of any one of claims 1 to 4, comprising:

(1) starting the UASB reactor:

anaerobic activated sludge of a sewage treatment plant is taken as an inoculum, primary sedimentation overflow liquid of the sewage treatment plant is taken as a culture medium, pure nitrogen is inoculated into a UASB reactor after being deoxidized, constant temperature culture is carried out at 37 ℃, and when the UASB reactor continuously generates methane, the start of the UASB reactor is finished;

(2) starting the microbial electrolytic cell:

anaerobic activated sludge of a sewage treatment plant is taken as an inoculum, primary sedimentation overflow liquid of the sewage treatment plant is taken as a culture medium, pure nitrogen is inoculated into a microbial electrolytic cell after being deoxidized, voltage is applied to the microbial electrolytic cell, constant temperature culture is carried out at 37 ℃, 70% of liquid in the microbial electrolytic cell is replaced by fresh deoxidized wastewater every 3-7 days, and when the current of the microbial electrolytic cell reaches the maximum and is stable, the starting of the microbial electrolytic cell is finished;

(3) culturing the electroactive anaerobic methanotrophic archaea and the hydrogenophilic methanogen:

the electro-active anaerobic methane nutrition archaea adoptsMethanosarcina acetivorans strain C2A，Methanosarcina acetivoransThe culture method of strain C2A comprises the following steps: inoculating Methanosarcina acetovorans strain C2A into an anaerobic bottle according to the volume ratio of 10%, and culturing at 37 ℃;

the hydrogenophilic methanogen adoptsMethanococcus maripaludis，Methanococcus maripaludisThe culture method comprises the following steps: sterile H for media in anaerobic flasks₂And CO₂Aerating the mixed gas for 30-45 minutes, wherein H in the mixed gas₂And CO of₂Is 8: 2; make H₂And CO₂The mixed gas maintains two atmospheric pressures, and then is connected into the anaerobic bottle according to the volume ratio of 10 percentMethanococcus maripaludisAnd cultured at 37 ℃;

(4) the process for converting organic wastewater into acetic acid is carried out after starting up a UASB reactor and a microbial electrolytic cell:

the electrolytic cell is filled with cultured electroactive anaerobic methanotrophic archaea and hydrogenophilic methanogens; in the electrolytic cell, anthraquinone-2, 6-disulfonate and Fe are present in the oxidation state³⁺For mediation, the introduced methane and hydrogen are converted into acetic acid under the action of electroactive anaerobic methanotrophic archaea and methanogens hydrogenophilous.

6. The method of claim 5, wherein:

and in the starting stage and the organic wastewater conversion stage, setting the potentials of the cathode electrodes in the microbial electrolytic cell and the electrolytic cell to be-0.3V to-2.0V, wherein the potentials are relative to the potential of a standard hydrogen electrode.

7. The method of claim 5, wherein:

the culture Medium in the anaerobic bottle is DSMZ Medium 141, and the components of the DSMZ Medium 141 are as follows:

KCl 0.34 g/L；MgCl₂·6H₂O 4.00 g/L；MgSO₄·7H₂O 3.45 g/L；NH₄Cl 0.25 g/L；CaCl₂·2H₂O 0.14 g/L；K₂HPO₄0.49 g/L; NaCl 18.00 g/L; fe (NH) at a concentration of 0.1% by mass/volume₄)₂(SO₄) ·6H₂O solution is 2 mL/L; 3.20g/L of methanol; 3.40g/L of sodium formate; 2.00g/L of yeast extract; peptone 2.00 g/L; the mass volume concentration of the resazurin solution is 0.1 percent, and the concentration of the resazurin solution is 0.50 mL/L; NaHCO 2₃5.00 g/L; 10mL/L of trace element solution; trace vitamin is 10.00 mL/L; 0.50g/L of monohydrate L-cysteine hydrochloride; na (Na)₂S·9H₂O0.50 g/L; 1000.00mL/L deionized water;

wherein, the microelement solution comprises the following components: nitrilotriacetic acid 1.5g/L, MgSO₄·7H₂O 3.0 g/L，MnSO₄·H₂O 0.5g/L，NaCl 1.0 g/L，FeSO₄·7H₂O 0.1 g/L，CoCl₂·6H₂O 0.1g/L，CaCl₂ 0.1 g/L，ZnSO₄·7H₂O 0.1g/L，CuSO₄·5H₂O 0.01g/L，AlK(SO₄)₂·12H₂O 0.01 g/L，H₃BO₃ 0.01g/L，Na₂MoO₄·2H₂0.01g/L of O and 1.0L/L of deionized water;

the trace element solution comprises the following components: 2.0mg/L of biotin, 2.0mg/L of folic acid, 10.0mg/L of vitamin B6 hydrochloride, 5.0mg/L of thiamine hydrochloride, 25.0 mg/L of vitamin B, 5.0mg/L of nicotinic acid, 5.0mg/L of D-calcium pantothenate, 120.1 mg/L of vitamin B, 5.0mg/L of p-aminobenzoic acid, 5.0mg/L of lipoic acid and 1.0L/L of deionized water.

8. The method of claim 5, wherein:

the organic wastewater is domestic sewage, food processing wastewater, starch processing wastewater or beer production wastewater.