A method for electrically enhanced biological treatment of chlorine-containing organic waste gas

Abstract

The present invention belongs to the field of environmental governance technology. The present invention provides a method for electrically enhanced biological treatment of chlorine-containing organic waste gas; the present invention is carried out in the manner of "electrolysis-biological-adsorption"; the present invention passes the waste gas into a plasma reactor for electrolysis, and high-energy electrons stimulate and ionize gases such as oxygen in the air, generate active groups and act on the waste gas, remove most of the chlorine-containing organic gases in the waste gas to obtain electrically treated waste gas; the electrically treated waste gas is introduced into a biological treatment tank; a conductive filler is obtained by electrospinning, and domesticated microorganisms are allowed to form biofilms on the surface of the filler, and a certain current is applied during the treatment process to stimulate the microbial reaction and increase physiological activity; the low-concentration chlorine-containing organic waste gas obtained at this time is close to the emission standard, and the chlorine-containing organic compounds therein are further reduced after adsorption by a macroporous resin to meet the emission standard. The treatment method provided by the present invention reduces the requirements and costs of various processes.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental treatment, and in particular to a method for electrically enhanced biological treatment of chlorine-containing organic waste gas. Background Art

[0002] In a society with rapidly advancing science and technology, people are increasingly enjoying the fruits of scientific and technological progress. However, the development of various industrial technologies also brings with it a host of problems. Waste generated during the production process is one of them, especially waste gas, which is in urgent need of treatment. Chlorinated volatile organic compounds (Cl-VOCs) have become the primary research target due to their widespread presence, inherent toxicity, and the production of polychlorinated byproducts. Chlorinated organic compounds are difficult to treat due to their inherent toxicity, high stability, and difficulty in degradation.

[0003] In the existing technology, the treatment of chlorine-containing organic waste gas mostly adopts the absorbent absorption method. The waste gas is passed into a low-volatile or non-volatile absorbent based on the principle of like dissolves like. The organic matter is then distilled or separated by different boiling points. However, in actual industrial applications, the absorbed organic solvent and surfactant will become waste liquid, causing secondary pollution. If the regeneration process is required, it will also increase the cost. Another commonly used method is the bio-photocatalytic method, which combines microbial degradation with hydroxyl radical oxidation degradation produced by photogenerated electrons to jointly degrade chlorine-containing organic waste gas. This method can effectively treat waste gas, but the reaction may be unstable and inefficient during the treatment process. Therefore, there is an urgent need for a low-cost and high-efficiency waste gas treatment method. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects in the prior art and provide a method for electrically enhanced biological treatment of waste gas.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a method for electrically enhanced biological treatment of chlorine-containing organic waste gas, comprising the following steps:

[0007] (1) electrolyzing chlorine-containing organic waste gas to obtain electrically treated waste gas;

[0008] (2) subjecting the electrically treated waste gas to microbial degradation to obtain low-concentration chlorine-containing organic waste gas;

[0009] (3) The low-concentration chlorine-containing organic waste gas is adsorbed by macroporous resin to complete the treatment.

[0010] Preferably, the number of positive electrodes for electrolysis in step (1) is 4 to 8, and the negative electrode for electrolysis is a nickel mesh or an aluminum mesh;

[0011] The discharge distance between the positive and negative electrodes of the electrolysis is 30 to 60 mm, and the discharge voltage is 18 to 22 kV.

[0012] Preferably, the gas flow rate of the electrolysis in step (1) is 350-400 mL / min.

[0013] Preferably, the microbial degradation in step (2) is carried out in water;

[0014] The water contains a carbon source, a nitrogen source and a filler;

[0015] The concentration of the carbon source is 0.15 to 0.22 mol / L, and the carbon-nitrogen ratio of the water is 7.5 to 9.3;

[0016] The carbon source is glucose, starch or sodium acetate, and the nitrogen source is urea or ammonium chloride.

[0017] Preferably, the method for preparing the filler comprises the following steps:

[0018] (a) Electrospinning a polyvinylidene fluoride (PVDF) solution in N,N-dimethylformamide to obtain a fiber membrane;

[0019] (b) mixing the fiber membrane, ascorbic acid and ferric chloride solution, and then adding sodium borohydride to carry out a reduction reaction to obtain the filler.

[0020] Preferably, the mass volume ratio of polyvinylidene fluoride to N,N-dimethylformamide in the N,N-dimethylformamide solution of polyvinylidene fluoride in step (a) is 1 g: 4-5 mL;

[0021] The polyvinylidene fluoride and N,N-dimethylformamide are mixed and then electrospun, wherein the mixing frequency is 25 to 30 kHz and the mixing time is 0.5 to 1 hour;

[0022] The voltage of the electrospinning is 12-16 kV, the injection speed is 18-20 mL / h, the distance between the needle and the receiving aluminum foil is 10-12 cm, and the inner diameter of the needle is 0.26-0.3 mm.

[0023] Preferably, in step (b), the mass ratio of the fiber membrane to ascorbic acid is 1:0.6-0.9;

[0024] The mass volume ratio of the fiber membrane and the ferric chloride solution is 1g:15-20mL;

[0025] The mass fraction of the ferric chloride solution is 23-26%;

[0026] The mass ratio of the fiber membrane to sodium borohydride is 1:0.5-0.8;

[0027] The stirring speed of the mixed solution in step (b) is 200-300 rpm, the temperature is 30-40° C., and the time is 1-1.5 h;

[0028] The reduction reaction is carried out at a stirring speed of 200 to 300 rpm, a temperature of 75 to 80° C., and a time of 0.5 to 1 h.

[0029] Preferably, the microbial degradation bacteria in step (2) are Bacillus licheniformis, Bacillus subtilis, white rot fungi, Sphingomonas or Methylobacterium extorquens DM4;

[0030] Mixing bacterial strains, a carbon source, a nitrogen source and water for acclimation to obtain a bacterial strain solution;

[0031] The carbon source is glucose, starch or sodium acetate, and the nitrogen source is urea or ammonium chloride;

[0032] The mass ratio of the bacterial strain to the carbon source is 1:0.8-1.2;

[0033] The mass ratio of the bacterial strain to the nitrogen source is 1:0.8-1.2; the mass volume ratio of the bacterial strain to water is 1g:8-12mL;

[0034] The acclimation temperature is 20-30°C and the time is 40-60 days;

[0035] The volume mass ratio of the bacterial solution to the filler in step (b) is 1 mL: 1.2-1.4 g;

[0036] Mixing the bacterial solution and the filler in step (b) before use;

[0037] The mixing temperature is 20-30° C. and the mixing time is 15-25 days.

[0038] Preferably, the temperature of the microbial degradation in step (2) is 20-30° C., the empty bed residence time is 3.5-120 s, and the current is 1.2-1.5 mA.

[0039] Preferably, the particle size of the macroporous resin in step (3) is D95, and the filling amount is 52 to 76 cm 3 The filling height is 0.012~0.02cm, the wind speed over the surface is ≤0.2m / s, the gas flow rate of low-concentration chlorine-containing organic waste gas is 600~800mL / min, and the pressure is 0.3~0.45MPa.

[0040] The present invention provides a method for electrically enhanced biological treatment of chlorine-containing organic waste gas. The method utilizes an "electrolysis-biological-adsorption" process. The chlorine-containing organic waste gas is passed through a plasma reactor for electrolysis. An external strong electric field is used to supply electron energy, thereby converting it into high-energy electrons. The high-energy electrons stimulate and ionize gases such as oxygen in the air, generating active radicals that act on the waste gas, removing most of the chlorine-containing organic gases in the waste gas and producing electrically treated waste gas. The electrically treated waste gas is then introduced into a biological treatment tank. This step focuses on the interaction between microbial treatment and electrical stimulation. Conductive fillers are obtained through electrospinning, and domesticated microorganisms are grown on the filler surface to form biofilms. During the treatment process, a certain current is applied to stimulate the microbial reaction and increase physiological activity, thereby achieving efficient microbial treatment and growth. The chlorine-containing organic compounds in the waste gas are oxidatively decomposed by microbial treatment in an aqueous environment. The low-concentration chlorine-containing organic waste gas obtained at this point is close to the emission standard. The chlorine-containing organic compounds are adsorbed by a macroporous resin, meeting the emission standard.

[0041] The treatment method provided by the present invention is simple and efficient, and the combined use of multiple processes can effectively treat chlorine-containing organic waste gas, and reduces the requirements of each process, thereby reducing costs. DETAILED DESCRIPTION

[0042] The present invention provides a method for electrically enhanced biological treatment of chlorine-containing organic waste gas, comprising the following steps:

[0043] (1) electrolyzing chlorine-containing organic waste gas to obtain electrically treated waste gas;

[0044] (2) subjecting the electrically treated waste gas to microbial degradation to obtain low-concentration chlorine-containing organic waste gas;

[0045] (3) The low-concentration chlorine-containing organic waste gas is adsorbed by macroporous resin to complete the treatment.

[0046] In the present invention, the electrolysis in step (1) is carried out in a plasma reactor.

[0047] In the present invention, the number of positive electrodes for electrolysis in step (1) is 4 to 8, and the negative electrode for electrolysis is a nickel mesh or an aluminum mesh.

[0048] In the present invention, electrolysis is carried out in a plexiglass box, with a cylindrical positive electrode installed at the upper end of the box, perpendicular to the lower surface; the positive electrode is made of stainless steel, and the lower surface of the box is covered with a negative electrode, the area of ​​the negative electrode is the same as the area of ​​the lower surface of the box; the distance between the positive and negative electrodes is the discharge distance.

[0049] In the present invention, the discharge distance between the positive and negative electrodes of the electrolysis is preferably 30 to 60 mm, more preferably 35 to 55 mm, and more preferably 40 to 50 mm; the discharge voltage is preferably 18 to 22 kV, more preferably 19 to 21 kV, and more preferably 19.5 to 20.5 kV.

[0050] In the present invention, the gas flow rate of the electrolysis in step (1) is preferably 350 to 400 mL / min, more preferably 360 to 390 mL / min, and even more preferably 370 to 380 mL / min.

[0051] In the present invention, the microbial degradation in step (3) is carried out in water.

[0052] In the present invention, the water contains a carbon source, a nitrogen source and a filler.

[0053] In the present invention, the concentration of the carbon source is preferably 0.15-0.22 mol / L, more preferably 0.16-0.21 mol / L, more preferably 0.18-0.19 mol / L; the carbon-nitrogen ratio of the water is preferably 7.5-9.3, more preferably 8-9, more preferably 8.4-8.6.

[0054] In the present invention, the carbon source is preferably glucose, starch or sodium acetate, and the nitrogen source is preferably urea or ammonium chloride.

[0055] In the present invention, the preparation method of the filler preferably comprises the following steps:

[0056] (a) Electrospinning a polyvinylidene fluoride (PVDF) solution in N,N-dimethylformamide to obtain a fiber membrane;

[0057] (b) After mixing the fiber membrane, ascorbic acid and ferric chloride solution, sodium borohydride is added to carry out a reduction reaction to obtain the filler.

[0058] In the present invention, the mass volume ratio of polyvinylidene fluoride to N,N-dimethylformamide in the N,N-dimethylformamide solution of polyvinylidene fluoride in step (a) is preferably 1 g:4-5 mL, more preferably 1 g:4.2-4.8 mL, and more preferably 1 g:4.4-4.6 mL.

[0059] In the present invention, polyvinylidene fluoride and N,N-dimethylformamide are mixed and then electrospun. The mixing frequency is preferably 25-30 KHz, more preferably 26-29 KHz, and more preferably 27-28 KHz. The mixing time is preferably 0.5-1 h, more preferably 0.6-0.9 h, and more preferably 0.7-0.8 h.

[0060] In the present invention, the voltage of the electrospinning is preferably 12 to 16 kV, more preferably 13 to 15 kV, and more preferably 13.5 to 14.5 kV; the injection speed is preferably 18 to 20 mL / h, more preferably 18.5 to 19.5 mL / h, and more preferably 18.8 to 19.2 mL / h; the distance between the needle and the receiving aluminum foil is preferably 10 to 12 cm, more preferably 10.5 to 11.5 cm, and more preferably 10.8 to 11.2 cm; the inner diameter of the needle is preferably 0.26 to 0.3 mm, more preferably 0.27 to 0.29 mm, and more preferably 0.275 to 0.285 mm.

[0061] In the present invention, the mass ratio of the fiber membrane to ascorbic acid in step (b) is preferably 1:0.6-0.9, more preferably 1:0.7-0.8, and even more preferably 1:0.74-0.76.

[0062] In the present invention, the mass volume ratio of the fiber membrane to the ferric chloride solution is preferably 1 g:15-20 mL, more preferably 1 g:16-19 mL, and even more preferably 1 g:17-18 mL.

[0063] In the present invention, the mass fraction of the ferric chloride solution is preferably 23-26%, more preferably 24-25%, and even more preferably 24.5-24.8%.

[0064] In the present invention, the mass ratio of the fiber membrane to sodium borohydride is preferably 1:0.5-0.8, more preferably 1:0.6-0.7, and even more preferably 1:0.65-0.66.

[0065] In the present invention, the stirring speed of the mixed solution in step (b) is preferably 200-300 rpm, more preferably 220-280 rpm, more preferably 240-260 rpm; the temperature is preferably 30-40°C, more preferably 32-38°C, more preferably 34-36°C; the time is preferably 1-1.5h, more preferably 1.1-1.4h, more preferably 1.2-1.3h.

[0066] In the present invention, the fiber membrane, ascorbic acid and ferric chloride solution are mixed and then partially reduced. The ascorbic acid partially reduces the trivalent iron ions to divalent iron ions, which facilitates the complete subsequent reduction reaction.

[0067] In the present invention, the stirring speed of the reduction reaction is preferably 200-300 rpm, more preferably 220-280 rpm, more preferably 240-260 rpm; the temperature is preferably 75-80°C, more preferably 76-79°C, more preferably 77-78°C; the time is preferably 0.5-1 h, more preferably 0.6-0.9 h, more preferably 0.7-0.8 h.

[0068] In the present invention, iron ions are reduced to elemental iron through the reducing action of sodium borohydride, thereby imparting conductive properties to the fibers and improving the physiological activity of the bacteria under current stimulation.

[0069] In the present invention, the microbial degradation bacteria in step (2) are preferably Bacillus licheniformis, Bacillus subtilis, white rot fungi, Sphingomonas or Methylobacterium extorquens DM4, more preferably Bacillus licheniformis and white rot fungi.

[0070] In the present invention, bacterial strains, a carbon source, a nitrogen source and water are mixed and acclimated to obtain a bacterial strain solution.

[0071] In the present invention, the carbon source is preferably glucose, starch or sodium acetate, and the nitrogen source is preferably urea or ammonium chloride.

[0072] In the present invention, the mass ratio of the bacterial species to the carbon source is preferably 1:0.8-1.2, more preferably 1:0.9-1.1, and even more preferably 1:0.95-1.05.

[0073] In the present invention, the mass ratio of the bacterial strain and the nitrogen source is preferably 1:0.8-1.2, more preferably 1:0.9-1.1, and more preferably 1:0.95-1.05; the mass volume ratio of the bacterial strain and water is preferably 1g:8-12mL, more preferably 1g:9-11mL, and more preferably 1g:9.5-10.5mL.

[0074] In the present invention, the acclimation temperature is preferably 20-30°C, more preferably 22-28°C, and more preferably 24-26°C; the acclimation time is preferably 40-60 days, more preferably 45-55 days, and more preferably 48-52 days.

[0075] In the present invention, the volume-to-mass ratio of the bacterial solution to the filler in step (b) is preferably 1 mL:1.2-1.4 g, more preferably 1 mL:1.25-1.35 g, and even more preferably 1 mL:1.28-1.32 g.

[0076] In the present invention, the bacterial seed solution and the filler in step (b) are mixed before use.

[0077] In the present invention, the mixing temperature is preferably 20-30°C, more preferably 22-28°C, more preferably 24-26°C; the mixing time is preferably 15-25 days, more preferably 16-24 days, more preferably 18-22 days.

[0078] In the present invention, after the bacterial solution and the filler are mixed, the bacterial strain can adhere to the filler, providing a basis for subsequent rapid reproduction and degradation.

[0079] In the present invention, microbial degradation is carried out in a closed degradation tank, and the area of ​​the filler is preferably 0.6 to 0.8 of the area of ​​the degradation tank, more preferably 0.65 to 0.75, and even more preferably 0.68 to 0.72.

[0080] In the present invention, the temperature of the microbial degradation in step (2) is preferably 20-30°C, more preferably 22-28°C, and more preferably 24-26°C; the empty bed residence time is preferably 3.5-120s, more preferably 10-60s, and more preferably 20-50s; the current is preferably 1.2-1.5mA, more preferably 1.25-1.45mA, and more preferably 1.3-1.4mA.

[0081] In the present invention, the particle size of the adsorbent macroporous resin in step (3) is preferably D95; the filling volume is preferably 52 to 76 cm 3 , more preferably 55 to 72 cm 3 , more preferably 57 to 68 cm 3 ; The filling height is preferably 0.012~0.02cm, more preferably 0.013~0.018cm, more preferably 0.015~0.017cm; the wind speed over the surface is preferably ≤0.2m / s, more preferably 0.05~0.16m / s; the gas flow rate of low-concentration chlorine-containing organic waste gas is preferably 600~800mL / min, more preferably 650~750mL / min, more preferably 680~720mL / min; the pressure is preferably 0.3~0.45MPa, more preferably 0.35~0.4MPa, more preferably 0.36~0.38MPa.

[0082] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0083] Example 1

[0084] The initial chlorine-containing organic waste gas is introduced into a plasma reactor, and four stainless steel positive electrodes and a nickel mesh negative electrode are set, with a discharge distance of 50 mm between the positive and negative electrodes; the waste gas is introduced into the reactor at a rate of 400 mL / min, and the discharge voltage is 20 kV for electrolysis to obtain electrically treated waste gas.

[0085] A solution of polyvinylidene fluoride and N,N-dimethylformamide was prepared in a ratio of 1 g:5 mL, and mixed at a frequency of 30 kHz for 0.5 h to obtain a spinning solution; the spinning solution was subjected to electrospinning at a voltage of 14 kV, a needle inner diameter of 0.3 mm, an injection speed of 18 mL / h, and a distance of 10 cm between the needle and the receiving aluminum foil to obtain a fiber membrane; the fiber membrane, ascorbic acid, and 25% ferric chloride solution were mixed in a ratio of 1 g:0.8 g:20 mL, and reacted at 250 rpm and 35°C for 1.5 h; sodium borohydride was added at a mass ratio of 1:0.8 between the fiber membrane and sodium borohydride, and the reaction was continued at 250 rpm and 80°C for 1 h. After the reaction, the product was rinsed with water and naturally dried to obtain a filler. Take Bacillus licheniformis and Bacillus subtilis, mix the strain, glucose, urea and water in a ratio of 1g:1.1g:1.2g:10mL, and acclimate at 25°C for 50 days to obtain a strain solution. During the acclimatization process, observe the strain state at all times, and add carbon source and nitrogen source according to the proportion; mix the strain solution and filler in a ratio of 1mL:1.35g, let it stand at 25°C for 20 days to obtain a usable filler. During the acclimatization process, observe the strain state at all times, and add carbon source and nitrogen source according to the proportion.

[0086] Place the usable filler in a closed degradation tank with an area of ​​the filler being 0.7 of the area of ​​the closed degradation tank. Then fill the degradation tank with water, add glucose and urea, control the glucose concentration to 0.15 mol / L, and the carbon-nitrogen ratio to 8. Then pass the electrically treated waste gas into the closed degradation tank, control the temperature to 25°C, the empty bed residence time to 10s, and apply a current of 1.3 mA to the filler for microbial degradation. Collect the low-concentration chlorine-containing organic gas generated during the degradation process for the next step of macroporous resin adsorption.

[0087] The low concentration of chlorine-containing organic gas is passed into the adsorbent macroporous resin, and the particle size is controlled to be D95 and the filling volume is 68cm 3 , filling height is 0.017cm, wind speed over the surface is 0.05m / s, gas flow rate is 750mL / min, pressure is 0.35MPa, and the waste gas treatment is completed.

[0088] The exhaust gas treated in this embodiment was tested, and the results are recorded in Table 1.

[0089] Example 2

[0090] The initial chlorine-containing organic waste gas was introduced into a plasma reactor, and 6 stainless steel positive electrodes and an aluminum mesh negative electrode were set, with a discharge distance of 40 mm between the positive and negative electrodes. The waste gas was introduced into the reactor at a rate of 350 mL / min, and the discharge voltage was 22 kV for electrolysis to obtain electrically treated waste gas.

[0091] A solution of polyvinylidene fluoride and N,N-dimethylformamide was prepared in a ratio of 1 g:4 mL, and mixed at a frequency of 25 kHz for 1 hour to obtain a spinning solution; the spinning solution was subjected to electrospinning at a voltage of 12.5 kV, a needle inner diameter of 0.28 mm, an injection speed of 19 mL / h, and a distance between the needle and a receiving aluminum foil of 12 cm to obtain a fiber membrane; the fiber membrane, ascorbic acid, and a 26% ferric chloride solution were mixed in a ratio of 1 g:0.6 g:16 mL, and reacted at 300 rpm and 40°C for 1.5 hours; sodium borohydride was added at a mass ratio of 1:0.7 between the fiber membrane and sodium borohydride, and the reaction was continued at 300 rpm and 75°C for 1 hour. After the reaction, the product was rinsed with water and naturally dried to obtain a filler. Take Bacillus subtilis and Sphingomonas, mix the strain, starch, ammonium chloride and water in a ratio of 1g:0.8g:1.1g:9mL, and acclimate at 30°C for 60 days to obtain a strain solution. During the acclimatization process, the strain state is always observed, and carbon source and nitrogen source are added according to the proportion; the strain solution and filler are mixed in a ratio of 1mL:1.2g, and allowed to stand at 30°C for 24 days to obtain a usable filler. During the acclimatization process, the strain state is always observed, and carbon source and nitrogen source are added according to the proportion.

[0092] Place the usable filler in a closed degradation tank with an area of ​​the filler being 0.65 of the area of ​​the closed degradation tank. Then fill the degradation tank with water, add starch and ammonium chloride, control the starch concentration to 0.20 mol / L, and the carbon-nitrogen ratio to 9.1. Then, pass the electrically treated waste gas into the closed degradation tank, control the temperature to 30°C, the empty bed residence time to 25s, and apply a current of 1.5mA to the filler for microbial degradation. Collect the low-concentration chlorine-containing organic gas generated during the degradation process for the next step of macroporous resin adsorption.

[0093] The low concentration of chlorine-containing organic gas is passed into the adsorbent macroporous resin, and the particle size is controlled to be D95 and the filling volume is 58cm 3 , filling height is 0.015cm, wind speed over the surface is 0.07m / s, gas flow rate is 600mL / min, pressure is 0.4MPa, and the waste gas treatment is completed.

[0094] The exhaust gas treated in this embodiment was tested, and the results are recorded in Table 1.

[0095] Example 3

[0096] The initial chlorine-containing organic waste gas was introduced into a plasma reactor, and 8 stainless steel positive electrodes and an aluminum mesh negative electrode were set, with a discharge distance of 30 mm between the positive and negative electrodes. The waste gas was introduced into the reactor at a rate of 360 mL / min, and the discharge voltage was 18 kV for electrolysis to obtain electrically treated waste gas.

[0097] A solution of polyvinylidene fluoride and N,N-dimethylformamide was prepared in a ratio of 1 g:4.8 mL, and mixed at a frequency of 28 kHz for 0.5 h to obtain a spinning solution; the spinning solution was subjected to electrospinning at a voltage of 14.8 kV, a needle inner diameter of 0.3 mm, an injection speed of 20 mL / h, and a distance of 10 cm between the needle and the receiving aluminum foil to obtain a fiber membrane; the fiber membrane, ascorbic acid, and 23% ferric chloride solution were mixed in a ratio of 1 g:0.8 g:19 mL, and reacted at 230 rpm and 40°C for 1 h; sodium borohydride was added at a mass ratio of 1:0.55 to the fiber membrane, and then the reaction was continued at 230 rpm and 80°C for 0.5 h. After the reaction, the product was rinsed with water and naturally dried to obtain a filler. Take Bacillus licheniformis and white rot fungus, mix the strain, glucose, urea and water in a ratio of 1g:1.1g:1.2g:11mL, and acclimate at 30°C for 60 days to obtain a strain solution. During the acclimatization process, the strain state is always observed, and carbon source and nitrogen source are added according to the proportion; the strain solution and filler are mixed in a ratio of 1mL:1.4g, and allowed to stand at 30°C for 15 days to obtain a usable filler. During the acclimatization process, the strain state is always observed, and carbon source and nitrogen source are added according to the proportion.

[0098] Place the usable filler in a closed degradation tank with an area of ​​the filler being 0.7 of the area of ​​the closed degradation tank. Then fill the degradation tank with water, add sodium acetate and ammonium chloride, control the concentration of sodium acetate to 0.18 mol / L, and the carbon-nitrogen ratio to 8.5. Then, pass the electrically treated waste gas into the closed degradation tank, control the temperature to 25°C, the empty bed residence time to 45s, and apply a current of 1.5mA to the filler for microbial degradation. Collect the low-concentration chlorine-containing organic gas generated during the degradation process for the next step of macroporous resin adsorption.

[0099] The low concentration of chlorine-containing organic gas is passed into the adsorbent macroporous resin, and the particle size is controlled to be D95 and the filling volume is 60cm 3 , filling height is 0.015cm, wind speed over the surface is 0.1m / s, gas flow rate is 780mL / min, pressure is 0.42MPa, and the waste gas treatment is completed.

[0100] The exhaust gas treated in this embodiment was tested, and the results are recorded in Table 1.

[0101] Example 4

[0102] The initial chlorine-containing organic waste gas was introduced into a plasma reactor, and 5 stainless steel positive electrodes and a nickel mesh negative electrode were set, with a discharge distance of 60 mm between the positive and negative electrodes. The waste gas was introduced into the reactor at a rate of 375 mL / min, and the discharge voltage was 22 kV for electrolysis to obtain electrically treated waste gas.

[0103] A solution of polyvinylidene fluoride and N,N-dimethylformamide was prepared in a ratio of 1 g:5 mL, and mixed at a frequency of 25 kHz for 1 hour to obtain a spinning solution; the spinning solution was subjected to electrospinning at a voltage of 13.5 kV, a needle inner diameter of 0.3 mm, an injection speed of 19 mL / h, and a distance of 11 cm between the needle and the receiving aluminum foil to obtain a fiber membrane; the fiber membrane, ascorbic acid, and 24% ferric chloride solution were mixed in a ratio of 1 g:0.6 g:17 mL, and reacted at 210 rpm and 35°C for 1.2 hours; sodium borohydride was added at a mass ratio of 1:0.75 between the fiber membrane and sodium borohydride, and the reaction was continued at 280 rpm and 78°C for 1 hour. After the reaction, the product was rinsed with water and naturally dried to obtain a filler. Take Methylobacterium extorquens DM4 and Sphingomonas sp., mix the strain, sodium acetate, urea and water in a ratio of 1g:0.8g:1.1g:9mL, and acclimate at 25°C for 40 days to obtain a strain solution. During the acclimatization process, the strain state is always observed, and carbon source and nitrogen source are added according to the proportion; the strain solution and filler are mixed in a ratio of 1mL:1.2g, and allowed to stand at 20°C for 20 days to obtain a usable filler. During the acclimatization process, the strain state is always observed, and carbon source and nitrogen source are added according to the proportion.

[0104] The usable filler is placed in a closed degradation tank with an area of ​​the filler being 0.66 of the area of ​​the closed degradation tank. Then, water is filled into the degradation tank, and starch and urea are added to control the starch concentration to 0.21 mol / L and the carbon-nitrogen ratio to 9. The electrically treated waste gas is then introduced into the closed degradation tank, the temperature is controlled to 30°C, the empty bed residence time is 50s, and the current applied to the filler is 1.4 mA for microbial degradation. The low-concentration chlorine-containing organic gas generated during the degradation process is collected for the next step of macroporous resin adsorption.

[0105] The low concentration of chlorine-containing organic gas is passed into the adsorbent macroporous resin, and the particle size is controlled to be D95 and the filling volume is 65cm 3 , filling height is 0.016cm, wind speed over the surface is 0.15m / s, gas flow rate is 660mL / min, pressure is 0.36MPa, and the waste gas treatment is completed.

[0106] The exhaust gas treated in this embodiment was tested, and the results are recorded in Table 1.

[0107] Table 1 Test results

[0108]

[0109]

[0110] As can be seen from the above examples, the present invention provides a method for electrically enhanced biological treatment of chlorine-containing organic waste gas. The present invention is carried out in an "electrolysis-biological-adsorption" manner; the present invention introduces chlorine-containing organic waste gas into a plasma reactor for electrolysis, and supplies electron energy through an external strong electric field, thereby converting it into high-energy electrons; the high-energy electrons stimulate and ionize gases such as oxygen in the air, generating active groups that act on the waste gas, removing most of the chlorine-containing organic gases in the waste gas to obtain electrically treated waste gas; the electrically treated waste gas is introduced into a biological treatment tank, and the focus of this step is on the treatment and electrical stimulation of microorganisms; a conductive filler is obtained by electrospinning, and domesticated microorganisms are formed on the surface of the filler. During the treatment process, a certain current is applied to stimulate the microbial reaction and increase physiological activity, thereby achieving efficient treatment and reproduction of microorganisms, and the chlorine-containing organic compounds in the waste gas are oxidized and decomposed by microorganisms in an aqueous environment; at this time, the low-concentration chlorine-containing organic waste gas obtained is close to the emission standard, and the chlorine-containing organic compounds therein are adsorbed by the macroporous resin to meet the emission standard. According to the description of the examples, the treatment method provided by the present application has a removal rate of 99.02% for Cl-VOCs in waste gas, effectively completing the waste gas treatment.

[0111] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for electrically enhanced biological treatment of chlorine-containing organic waste gas, characterized in that: It includes the following steps: (1) Passing chlorine-containing organic waste gas into a plasma reactor for electrolysis to obtain electrically treated waste gas; (2) subjecting the electrically treated waste gas to microbial degradation to obtain low-concentration chlorine-containing organic waste gas; (3) The low-concentration chlorine-containing organic waste gas is adsorbed by macroporous resin to complete the treatment; In step (2), the microbial degradation is carried out in water; The water contains a carbon source, a nitrogen source and a filler; The preparation method of the filler comprises the following steps: (a) Electrospinning of polyvinylidene fluoride in N,N-dimethylformamide to obtain a fiber membrane; (b) mixing the fiber membrane, ascorbic acid and ferric chloride solution, and then adding sodium borohydride to carry out a reduction reaction to obtain the filler; Mixing the bacterial solution and the filler in step (b) to obtain a usable filler; The process of subjecting the electrically treated waste gas to microbial degradation in step (2) is as follows: placing the usable filler in a closed degradation tank, filling it with water, adding a carbon source and a nitrogen source, and then passing the electrically treated waste gas into the closed degradation tank for microbial degradation.

2. The method according to claim 1, wherein The number of positive electrodes of the electrolysis in step (1) is 4 to 8, and the negative electrode of the electrolysis is a nickel mesh or an aluminum mesh; The discharge distance between the positive and negative electrodes of the electrolysis is 30-60 mm, and the discharge voltage is 18-22 kV.

3. The method according to claim 1 or 2, wherein: The gas flow rate of the electrolysis in step (1) is 350-400 mL / min.

4. The method according to claim 1, wherein The concentration of the carbon source is 0.15-0.22 mol / L, and the carbon-nitrogen ratio of the water is 7.5-9.3; The carbon source is glucose, starch or sodium acetate, and the nitrogen source is urea or ammonium chloride.

5. The method according to claim 4, wherein The mass volume ratio of polyvinylidene fluoride to N,N-dimethylformamide in the N,N-dimethylformamide solution of polyvinylidene fluoride in step (a) is 1 g: 4-5 mL; The polyvinylidene fluoride and N,N-dimethylformamide are mixed and then electrospun, wherein the mixing frequency is 25 to 30 kHz and the mixing time is 0.5 to 1 hour; The electrospinning voltage is 12-16 kV, the injection speed is 18-20 mL / h, the distance between the needle and the receiving aluminum foil is 10-12 cm, and the inner diameter of the needle is 0.26-0.3 mm.

6. The method according to claim 5, wherein The mass ratio of the fiber membrane to ascorbic acid in step (b) is 1:0.6-0.9; The mass volume ratio of the fiber membrane and the ferric chloride solution is 1g:15~20mL; The mass fraction of the ferric chloride solution is 23-26%; The mass ratio of the fiber membrane to sodium borohydride is 1:0.5-0.8; The stirring speed of the mixed solution in step (b) is 200-300 rpm, the temperature is 30-40° C., and the time is 1-1.5 h; The reduction reaction is carried out at a stirring speed of 200-300 rpm, a temperature of 75-80° C., and a time of 0.5-1 h.

7. The method according to claim 6, wherein The bacterial solution is obtained by mixing bacterial strains, a carbon source, a nitrogen source and water for acclimation; The bacterial species is Bacillus licheniformis, Bacillus subtilis, white rot fungus, Sphingomonas or Methylobacterium extorquens DM4; The carbon source is glucose, starch or sodium acetate, and the nitrogen source is urea or ammonium chloride; The mass ratio of the bacterial strain to the carbon source is 1:0.8-1.2; The mass ratio of the bacterial strain to the nitrogen source is 1:0.8-1.2; the mass volume ratio of the bacterial strain to water is 1g:8-12mL; The acclimation temperature is 20-30°C and the time is 40-60 days; The volume-to-mass ratio of the bacterial solution to the filler in step (b) is 1 mL: 1.2-1.4 g; The mixing temperature is 20-30° C. and the mixing time is 15-25 days.

8. The method according to claim 1 or 7, wherein: The temperature of the microbial degradation in step (2) is 20-30°C, the empty bed residence time is 3.5-120s, and the current is 1.2-1.5mA.

9. The method according to claim 8, wherein The particle size of the macroporous resin in step (3) is D95, and the filling volume is 52~76cm 3 The filling height is 0.012~0.02cm, the wind speed over the surface is ≤0.2m / s, the gas flow rate of low-concentration chlorine-containing organic waste gas is 600~800mL / min, and the pressure is 0.3~0.45MPa.

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