A method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms

Abstract

The present invention relates to the technical field of organic waste gas treatment, and specifically to an organic waste gas treatment method based on the combination of high-efficiency activated carbon and microorganisms, comprising the following steps: S1, preparation of a microbial agent; S2, preparation of reusable activated carbon; S3, preparation of an activated carbon-microorganism composite carrier; S4, treatment of organic waste gas; the present invention semi-wraps a microbial composite film on the surface of the reusable activated carbon, while not affecting the contact between the activated carbon and the organic waste gas, utilizes the synergistic area formed by the microorganisms between the film and the activated carbon to more effectively degrade and adsorb the organic waste gas, thereby further improving the adsorption efficiency; the semi-wrap design can provide a suitable growth environment for the microorganisms while maintaining a certain air permeability, which is beneficial to the growth and metabolism of the microorganisms, and can also effectively reduce the replacement frequency of the activated carbon, thereby further reducing the cost of waste gas treatment.

Description

Technical Field

[0001] The invention relates to the technical field of organic waste gas treatment, and in particular to an organic waste gas treatment method based on the combination of high-efficiency activated carbon and microorganisms. Background Art

[0002] High-efficiency activated carbon usually has a porous structure, a large specific surface area and abundant surface chemical groups, which endow it with excellent adsorption capacity. The pores of activated carbon vary in size, with micropores dominating. These pores can effectively adsorb organic matter in wastewater, including non-water-soluble organic solvents. The surface chemical properties of activated carbon, such as acidic and alkaline surface functional groups, affect its adsorption performance for pollutants.

[0003] Microorganisms can use pollutants in organic waste gas as a source of energy and convert them into harmless substances such as carbon dioxide and water through metabolism. This process is called biodegradation, and microorganisms play a key role in this process. Biological treatment is also effective for organic waste gas that is poorly water-soluble and difficult to biodegrade, and will not cause secondary pollution.

[0004] Activated carbon provides physical adsorption, and microorganisms provide biodegradation. The combination of the two can more thoroughly remove organic pollutants in waste gas. Compared with simple physical or chemical treatment methods, the biodegradation of microorganisms does not require additional chemical reagents, reducing treatment costs. At the same time, this method does not produce secondary pollution, which is in line with the concept of green environmental protection. It can adapt to organic waste gas of different concentrations and compositions, and has high flexibility.

[0005] However, the high-efficiency activated carbon and microbial combined treatment method also has the following disadvantages: Activated carbon saturation problem: Activated carbon is easily saturated and needs to be replaced or regenerated regularly, which increases the treatment cost. Limitations of microbial culture and reaction conditions: Microbial culture requires specific temperature, humidity and nutrients, and these conditions need to be strictly controlled during the treatment process, which increases the difficulty and cost of treatment. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms.

[0007] The technical solution of the present invention is: a method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms, comprising the following steps:

[0008] S1. Preparation of microbial inoculants

[0009] The Pseudomonas proteus strain is taken out and pretreated to obtain activated bacterial bodies; the activated bacterial bodies are inoculated into a beef extract peptone medium at a volume ratio of 2.5-3.5% for low-density fermentation treatment, and then the activated bacterial bodies after the low-density fermentation treatment are inoculated into an LB medium at a volume ratio of 4.2-6.2% for liquid deep fermentation treatment to obtain a liquid bacterial agent, and finally the liquid bacterial agent obtained by the fermentation is dried and crushed to obtain a solid bacterial agent;

[0010] S2. Preparation of reusable activated carbon

[0011] S2-1, coating the surface of activated carbon microspheres with a diameter of 250-450 nm with a dispersion liquid, with a coating thickness of 20-30 nm, activating the surface for 4-6 min and drying the surface at 35-40° C. for 2-3 min to obtain swollen activated carbon microspheres;

[0012] S2-2, coating a SiO2 layer with a thickness of 0.03 to 0.05 μm on the surface of the swelling activated carbon microspheres to obtain reusable activated carbon;

[0013] S3. Preparation of activated carbon-microorganism composite carrier

[0014] In percentage by mass, 35-40% of solid bacterial agent, 15-20% of microbial extracellular polysaccharide, 10-12% of volcanic rock powder and the rest of deionized water are mixed to obtain an attachment liquid, and then the attachment liquid is used to partially impregnate the reusable activated carbon prepared in step S2-2, so that the attachment liquid is half-wrapped on the surface of the reusable activated carbon, the impregnation time is 13-15 minutes, the thickness is 30-40 nm, and after the impregnation is completed, it is taken out and dried at 30-35° C. to obtain an activated carbon-microorganism composite carrier;

[0015] S4. Treatment of organic waste gas

[0016] The activated carbon-microorganism composite carrier prepared in step S3 is placed in a container, and then the organic waste gas to be treated is introduced into the container, and reacts for 2 to 5 hours until the treatment is completed, and then the activated carbon-microorganism composite carrier is taken out and desorbed for reuse;

[0017] Description: The present invention provides a process for the microorganisms to gradually adapt to the production environment by first performing low-density fermentation on the microorganisms, so that they can perform better in the subsequent high-density fermentation. Low-density fermentation helps microorganisms establish stable metabolic pathways and reduce metabolic disorders that may occur during high-density fermentation. High-density fermentation can significantly improve the metabolic activity of microorganisms, accelerate the accumulation of target products, and thus improve the performance of microbial agents; and by coating the surface of the swelling activated carbon microspheres with silica, the pore volume and pore size distribution of the activated carbon can be effectively improved, thereby improving its adsorption efficiency; the use of activated carbon microspheres coated with silica can also help reduce the environmental release of harmful substances, and the swelling activated carbon microspheres coated with silica can maintain their performance in multiple cycles due to the chemical stability and heat resistance of their surfaces, thereby improving the reuse performance; combining activated carbon and microorganisms in the form of an activated carbon-microorganism composite carrier can effectively utilize the biofilm formed by microorganisms on the surface of the activated carbon to biodegrade some pollutants adsorbed by the activated carbon, thereby regenerating the activated carbon, extending its service life, reducing the regeneration frequency of the activated carbon, reducing the treatment cost, and being more environmentally friendly.

[0018] Further, in step S1, the pretreatment method is: adding 2.5-4.5 wt.% of mannitol to the Pseudomonas proteans strain at a rate of 2-3 mL / min, and then culturing at a temperature of 28-32° C. for 24-36 hours;

[0019] Description: Mannitol can protect bacteria from oxidative stress and promote their activation; mannitol can serve as a carbon source for Pseudomonas and promote the growth of bacteria.

[0020] Furthermore, in step S1, the culture temperature of the low-density fermentation treatment is 30-35° C., the oscillation speed is 80-160 r / min, the culture time is 30-40 h, and after the culture is completed, the culture solution is centrifuged at a speed of 7000-9000 r / min for 8-12 min, and the supernatant is discarded;

[0021] The liquid deep fermentation treatment method comprises: firstly, oscillating culture is performed for 15 to 20 hours at a temperature of 20 to 25° C. and an oscillating speed of 300 to 500 r / min, and after the oscillating culture is completed, the phosphate buffer is used for washing 2 to 4 times, and the washing liquid is used as a bacterial suspension; then, the bacterial suspension is passed through sterile air until the pressure is 0.03 to 0.05 MPa, the temperature is 28 to 38° C., the rotation speed is 180 to 220 r / min, and the dissolved oxygen is ≥18%, and the culture is continued for 4 to 8 hours to obtain a liquid bacterial agent;

[0022] Description: Beef extract peptone medium can avoid excessive microbial growth caused by excessive nutrient concentration during low-density fermentation. At the same time, beef extract peptone medium does not contain antibiotics, which can effectively prevent antibiotics from interfering with bacterial growth. Low-density fermentation helps to activate beneficial bacteria, while deep fermentation is carried out at a lower temperature, which helps to improve the activity of specific microbial strains and further improve the ability of microorganisms to decompose organic matter. The ions in the phosphate buffer can enhance the activity of microorganisms by interacting with the negative charges on the surface of microorganisms. The phosphate buffer can effectively neutralize the acidic substances produced during the fermentation process and maintain a suitable pH environment, which is conducive to the normal growth of microorganisms. In addition, the ions in the phosphate buffer can enhance the activity of microorganisms, improve their metabolic capacity and growth rate, and contribute to the efficiency of high-density fermentation. At the same time, the phosphate buffer can effectively prevent microbial contamination, ensure the purity of the culture, and further improve the treatment effect of microbial agents on organic waste gas.

[0023] Furthermore, in step S2-1, the dispersion is packaged in a layered manner, and the layered packaging includes the following steps:

[0024] (1) Dividing the dispersion into 3 to 4 equal parts;

[0025] (2) adding microspheres to one of the dispersions, wrapping the microspheres on the surface of the microspheres in a mass volume ratio of 1 g: 3-5 mL of the dispersion, taking out and drying at 30-40° C. to obtain a microporous layer; then taking out another portion of the dispersion, spraying 2.5-4.5 wt.% of lignite humic acid into the dispersion, stirring evenly to obtain a mixed solution, wrapping the microspheres on the surface of the microspheres in a mass volume ratio of 1 g: 5-7 mL of the mixed solution, and then drying at 45-55° C. to obtain a transition layer; finally, taking the remaining dispersion and cellulose in a mass volume ratio of 2.5-4.5 wt.% of the dispersion, wrapping the microspheres on the surface of the transition layer in a mass volume ratio of 1 g: 9-11 mL of the mixed solution, and finally drying at 22-26° C. to obtain a macroporous layer; wherein the pore size of the microporous layer is less than the pore size of the transition layer and less than the pore size of the macroporous layer; and the pore size of the macroporous layer is 6-10 nm.

[0026] Description: The multi-layer structure enables the activated carbon to adsorb molecules of different sizes at the same time during the adsorption process, thus improving the adsorption efficiency. During the desorption process, the macroporous layer first desorbs the macromolecular substances, followed by the medium-molecular substances in the transition layer and the small-molecular substances in the microporous layer. This orderly desorption process helps to reduce the pore blockage of the activated carbon and improve the regeneration efficiency. Since the multi-layer structure improves the adsorption efficiency and regeneration efficiency of the activated carbon, the activated carbon can still maintain good performance after multiple uses, thereby extending its service life. The multi-layer structure also helps to reduce the wear and breakage of the activated carbon during use, further improving its reusability.

[0027] Furthermore, the dispersion is obtained by mixing titanium gel, dispersant and solvent in a weight ratio of 0.8-1.2:2-3:5-7; the solvent is amyl alcohol or cyclopentanone; the dispersant is polystyrene or polyvinyl pyridine;

[0028] Description: Titanium gel, as a hard material, can provide support in the preparation process of activated carbon micropores and help form a more ordered and regular pore structure. Titanium gel itself has certain adsorption properties. Combining it with activated carbon can further improve the adsorption performance of activated carbon, so that the activated carbon micropores can better adsorb harmful substances; Titanium gel provides a suitable growth environment for microorganisms, which helps the attachment and growth of microorganisms on the surface of activated carbon. The microorganisms attached to the surface of activated carbon can accelerate the biodegradation of harmful substances through their metabolic activities, further improving the treatment efficiency of activated carbon; Pentanol and cyclopentanone, as organic solvents, can better penetrate into the pores of activated carbon and dissolve impurities and residues therein, thereby helping to clean the surface of activated carbon and improve its pore-making effect; Polystyrene can affect the microstructure of activated carbon, and may control the pore size distribution by regulating the degree of polymerization and cross-linking density, thereby optimizing the adsorption performance of activated carbon; Polyvinylpyridine can change the wettability of the activated carbon surface and help the activated carbon to be better dispersed in the medium, thereby affecting the pore structure of activated carbon.

[0029] Furthermore, in step S2-1, the activation treatment method is: placing the activated carbon microspheres coated with the dispersion in a preheating tank at 70-75°C for preheating treatment for 10-15 minutes, then transferring the preheated microspheres to an activation furnace, and passing 750-850°C water vapor into the activation furnace in an oxygen-free environment. After activation treatment for 30-50 minutes, the microspheres are cooled to room temperature in a nitrogen or argon atmosphere.

[0030] Note: Preheating may be a necessary step to increase the reactivity of the microspheres and the dispersion. In the activation furnace, the activated carbon microspheres will react with water vapor at high temperature to generate a new pore structure. Water vapor reacts with the dispersion components on the surface of the activated carbon microspheres, which may generate new compounds or structures; quickly reduce its temperature to prevent the adverse effects caused by overheating; slowly cool to room temperature under nitrogen or argon protection to facilitate the formation of swollen activated carbon microspheres. This method can effectively prevent the oxidation and rupture of the activated carbon microspheres during the cooling process, thereby ensuring its pore structure and adsorption performance.

[0031] Furthermore, in step S3, the local impregnation method is: suspending the reusable activated carbon in the attachment liquid, and chemically depositing the attachment liquid on the surface of the bottom of the reusable activated carbon through ultrasonic treatment to form a thin film, the deposition time is 30 to 40 seconds, the deposition temperature is 55 to 65°C, and the deposition thickness is 30 to 40 nm.

[0032] Note: The above-mentioned deposition parameters can improve the uniformity of the distribution of the impregnated material on the surface of activated carbon, while avoiding damage to the structure of the activated carbon itself, so that the impregnated material on the surface of the activated carbon can fully exert its adsorption effect and further improve the overall adsorption performance of the activated carbon.

[0033] Furthermore, the parameters of the ultrasonic treatment are: ultrasonic power density is 0.8-1 W / cm 2 , amplitude is 5-10nm, time is 10-12s;

[0034] Note: The above ultrasonic parameters can effectively avoid the intensified movement of microspheres caused by liquid overheating, so that the reusable activated carbon stays relatively stably on the top of the attachment liquid, thereby improving the local impregnation effect of the attachment liquid.

[0035] Further, in step S4, the desorption treatment method is: passing steam at a temperature of 40 to 50° C. and a pressure of 0.5 to 0.7 MPa into a container containing an activated carbon-microorganism composite carrier to be desorbed, so that the adsorbate in the activated carbon is desorbed for 20 to 30 minutes, and then taken out and dried at 55 to 65° C.; wherein the volume ratio of the steam to the activated carbon-microorganism composite carrier is 3:2 to 4;

[0036] Description: Thermal desorption can effectively utilize the conditions of temperature and air flow to decompose and detach the adsorbed substances, effectively restoring the adsorption performance of activated carbon. After desorption, the activated carbon can be used again to adsorb organic waste gas for recycling; steam desorption can achieve desorption at a lower temperature and will not cause structural damage to the activated carbon, effectively improving the service life of the activated carbon-microorganism composite carrier.

[0037] The beneficial effects of the present invention are:

[0038] (1) The present invention can effectively improve the pore volume and pore size distribution of activated carbon by coating the surface of swellable activated carbon microspheres with silicon dioxide, thereby improving its adsorption efficiency; the use of activated carbon microspheres coated with silicon dioxide can also help reduce the environmental release of harmful substances. At the same time, the swellable activated carbon microspheres coated with silicon dioxide can maintain their performance during multiple cycles due to the chemical stability and heat resistance of their surfaces, thereby improving the recycling performance.

[0039] (2) The present invention semi-wraps the surface of the reusable activated carbon with a microbial composite film. This can fully utilize the synergistic area formed between the film and the activated carbon without affecting the contact between the activated carbon and the organic waste gas, more effectively degrade and adsorb the organic waste gas, and further improve the adsorption efficiency. The semi-wrapped design can provide a suitable growth environment for the microorganisms while maintaining a certain air permeability, which is beneficial to the growth and metabolism of the microorganisms. It can also effectively reduce the replacement frequency of the activated carbon, further reducing the cost of waste gas treatment.

[0040] (3) The present invention utilizes a dispersed liquid to layeredly coat the surface of activated carbon, which can effectively utilize the multi-layer structure, promote the activated carbon to adsorb molecules of different sizes at the same time, and further improve the adsorption efficiency; and the layered coated activated carbon can sequentially and orderly desorb large molecules, medium molecules and small molecules during the desorption process. This desorption process helps to reduce the pore blockage rate of the activated carbon and improve the regeneration efficiency; because the multi-layer structure improves the adsorption efficiency and regeneration efficiency of the activated carbon, the activated carbon can still maintain good performance after multiple uses, thereby extending its service life; the multi-layer structure also helps to reduce the wear and breakage of the activated carbon during use, further improving its reusability. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a trend chart of the change of the organic waste gas treatment effect of the activated carbon-microorganism composite carrier prepared in Examples 1 to 9 of the present invention and Comparative Examples 1 to 2;

[0042] Figure 2 It is a trend chart of the recovery rate of the adsorption performance of the activated carbon-microorganism composite carrier prepared in Examples 1 to 9 of the present invention and Comparative Examples 1 to 2;

[0043] Figure 3 It is a trend chart of the treatment effect of organic waste gas of the activated carbon-microorganism composite carrier prepared in Example 1, Example 10 to Example 18, Example 27 to Example 28 and Comparative Examples 3 to 4 of the present invention;

[0044] Figure 4 It is a trend chart of the recovery rate of the adsorption performance of the activated carbon-microorganism composite carrier prepared in Example 1, Example 10 to Example 18, Example 27 to Example 28 and Comparative Examples 3 to 4 of the present invention;

[0045] Figure 5 It is a trend chart of the treatment effect of organic waste gas of the activated carbon-microorganism composite carrier prepared in Example 1, Example 19 to Example 26 and Comparative Examples 5 to 6 of the present invention;

[0046] Figure 6It is a trend chart of the recovery rate of the adsorption performance of the activated carbon-microorganism composite carriers prepared in Example 1, Examples 19 to 26 and Comparative Examples 5 to 6 of the present invention. DETAILED DESCRIPTION

[0047] In order to further illustrate the method adopted by the present invention and the effect achieved, the technical solution of the present invention will be clearly and completely described in combination with experiments below.

[0048] Example 1: A method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms, comprising the following steps:

[0049] S1. Preparation of microbial inoculants

[0050] The Pseudomonas proteus strain is taken out and pretreated to obtain activated bacteria; the activated bacteria are inoculated into a beef extract peptone medium at a volume ratio of 3.0% for low-density fermentation treatment, and then the activated bacteria after the low-density fermentation treatment are inoculated into an LB medium at a volume ratio of 5.2% for liquid deep fermentation treatment to obtain a liquid bacterial agent, and finally the liquid bacterial agent obtained by the fermentation is dried and crushed to obtain a solid bacterial agent;

[0051] The pretreatment method is as follows: adding 3.5 wt.% of mannitol to the Pseudomonas proteans strain at a rate of 2.5 mL / min, and then culturing at a temperature of 30° C. for 30 hours;

[0052] The culture temperature of the low-density fermentation treatment was 33°C, the shaking speed was 120 r / min, the culture time was 35 h, and after the culture was completed, the culture solution was centrifuged at a speed of 8000 r / min for 10 min, and the supernatant was discarded;

[0053] The method of liquid deep fermentation treatment is: first, oscillate and culture for 18 hours at a temperature of 23°C and an oscillation speed of 400 r / min, wash three times with phosphate buffer after the oscillation culture is completed, and use the washing liquid as a bacterial suspension; then, pass sterile air through the bacterial suspension until the pressure is 0.04 MPa, the temperature is 33°C, the rotation speed is 200 r / min, and the dissolved oxygen is 18%, and continue to culture for 6 hours to obtain a liquid bacterial agent;

[0054] S2. Preparation of reusable activated carbon

[0055] S2-1, coating the surface of activated carbon microspheres with a diameter of 350 nm with a dispersion liquid to a coating thickness of 25 nm, activating the surface for 5 min and drying the surface at 37° C. for 2.5 min to obtain swollen activated carbon microspheres;

[0056] In step S2-1, the activation treatment method is: placing the activated carbon microspheres coated with the dispersion in a preheating tank at 73°C for preheating for 13 minutes, then transferring the preheated microspheres to an activation furnace, introducing 800°C water vapor into the activation furnace in an oxygen-free environment, activating for 40 minutes, and then cooling to room temperature in a nitrogen or argon atmosphere;

[0057] S2-2, coating a SiO2 layer with a thickness of 0.04 μm on the surface of the swelling activated carbon microspheres to obtain reusable activated carbon;

[0058] S3. Preparation of activated carbon-microorganism composite carrier

[0059] In percentage by mass, 38% of solid bacterial agent, 18% of microbial extracellular polysaccharide, 11% of volcanic rock powder with a particle size of 15 to 20 nm and the rest of deionized water are mixed to obtain an attachment liquid, and then the attachment liquid is used to partially impregnate the reusable activated carbon prepared in step S2-2, so that the attachment liquid is half-wrapped on the surface of the reusable activated carbon, the impregnation time is 14 minutes, the thickness is 35 nm, and after the impregnation is completed, it is taken out and dried at 33° C. to obtain an activated carbon-microorganism composite carrier;

[0060] In step S3, the local impregnation method is: suspending the reusable activated carbon in the attachment liquid, and using ultrasonic treatment to chemically deposit the attachment liquid on the surface of the bottom of the reusable activated carbon to form a thin film, the deposition time is 35s, the deposition temperature is 60°C, and the deposition thickness is 35nm; the parameters of the ultrasonic treatment are: ultrasonic power density is 0.9W / cm 2 , amplitude is 8nm, time is 11s;

[0061] S4. Treatment of organic waste gas

[0062] The activated carbon-microorganism composite carrier prepared in step S3 is placed in a container, and then the organic waste gas after chemical washing in a washing tower and impurity removal in a biological trickling filter is introduced into the container, and reacted for 3.5 hours until the treatment is completed, and then the activated carbon-microorganism composite carrier is taken out and desorbed for reuse;

[0063] In step S4, the desorption treatment method is: steam with a temperature of 45°C and a pressure of 0.6MPa is passed into a container containing the activated carbon-microorganism composite carrier to be desorbed, so that the adsorbate in the activated carbon is desorbed, the desorption time is 25min, and after taking out, it is dried at 60°C; wherein the volume ratio of steam to the activated carbon-microorganism composite carrier is 3:3.

[0064] Example 2: Different from Example 1, the pretreatment method is: add 2.5 wt.% of mannitol to the Pseudomonas aeruginosa strain at a rate of 2 mL / min, and then culture at a temperature of 28° C. for 36 h.

[0065] Example 3: Different from Example 1, the pretreatment method is: 4.5 wt.% of mannitol is added to the Pseudomonas aeruginosa strain at a rate of 3 mL / min, and then cultured at a temperature of 32° C. for 24 h.

[0066] Example 4: Different from Example 1, the activated bacteria are inoculated into beef extract peptone culture medium at an inoculum volume ratio of 2.5% for low-density fermentation treatment, and then the activated bacteria after completing the low-density fermentation treatment are inoculated into LB culture medium at an inoculum volume ratio of 4.2% for liquid deep fermentation treatment.

[0067] Example 5: Different from Example 1, the activated bacteria are inoculated into beef extract peptone culture medium at an inoculum volume ratio of 3.5% for low-density fermentation treatment, and then the activated bacteria after the low-density fermentation treatment are inoculated into LB culture medium at an inoculum volume ratio of 6.2% for liquid deep fermentation treatment.

[0068] Example 6: Different from Example 1, the culture temperature of the low-density fermentation treatment is 30°C, the oscillation speed is 80r / min, the culture time is 30h, and after the culture is completed, the culture solution is centrifuged at a speed of 7000r / min for 12min, and the supernatant is discarded.

[0069] Example 7: Different from Example 1, the culture temperature of the low-density fermentation treatment is 35°C, the oscillation speed is 160r / min, the culture time is 40h, and after the culture is completed, the culture solution is centrifuged at a speed of 9000r / min for 8min, and the supernatant is discarded.

[0070] Example 8: Different from Example 1, the method of liquid deep fermentation treatment is: first, oscillate and culture for 20 hours at a temperature of 20°C and an oscillation speed of 300 r / min, and after the oscillation culture is completed, wash twice with phosphate buffer, and use the washing liquid as the bacterial suspension; then pass sterile air through the bacterial suspension to a pressure of 0.03 MPa, a temperature of 28°C, a rotation speed of 180 r / min, and a dissolved oxygen of 18%, and continue to culture for 4 hours to obtain a liquid bacterial agent.

[0071] Example 9: Different from Example 1, the method of liquid deep fermentation treatment is: first, oscillate and culture for 15 hours at a temperature of 25°C and an oscillation speed of 500 r / min, and after the oscillation culture is completed, wash 4 times with phosphate buffer, and use the washing liquid as the bacterial suspension; then pass sterile air through the bacterial suspension to a pressure of 0.05 MPa, a temperature of 38°C, a rotation speed of 220 r / min, and a dissolved oxygen of 18%, and continue to culture for 8 hours to obtain a liquid bacterial agent.

[0072] Example 10: Different from Example 1, S2-1, the dispersion is coated on the surface of activated carbon microspheres with a diameter of 250 nm, the coating thickness is 20 nm, and after the coating is completed, it is activated for 4 minutes and dried at 35°C for 3 minutes to obtain swollen activated carbon microspheres.

[0073] Example 11: Different from Example 1, S2-1, the dispersion is coated on the surface of activated carbon microspheres with a diameter of 450nm, the coating thickness is 30nm, and after the coating is completed, it is activated for 6min and dried at 40°C for 2min to obtain swollen activated carbon microspheres.

[0074] Embodiment 12: Different from Embodiment 1, in step S2-1, the dispersion is wrapped in a layered manner, and the layered wrapping includes the following steps:

[0075] (1) Divide the dispersion into three equal parts;

[0076] (2) adding microspheres to one of the dispersions, wrapping the microspheres on the surface of the microspheres in a mass volume ratio of 1 g:3 mL of the dispersion, taking out and drying at 30°C to obtain a microporous layer; then taking out one of the dispersions, spraying 2.5 wt.% of lignite humic acid into the dispersion, stirring evenly to obtain a mixed solution, wrapping the microspheres in a ratio of 1 g:5 mL of the mixed solution, and then drying at 45°C to obtain a transition layer; finally taking the remaining dispersion and cellulose in a ratio of 2.5 wt.% of the dispersion, wrapping the microspheres on the surface of the transition layer in a mass volume ratio of 1 g:9 mL of the mixed solution, and finally drying at 22°C to obtain a macroporous layer; wherein the pore size of the microporous layer is less than the pore size of the transition layer and less than the pore size of the macroporous layer; the pore size of the macroporous layer is 6 nm;

[0077] The dispersion is obtained by mixing titanium gel, a dispersant and a solvent in a weight ratio of 0.8:2:5; the solvent is amyl alcohol; and the dispersant is polyvinyl pyridine.

[0078] Example 13: Different from Example 12, the microspheres are wrapped on the surface of the microspheres in a mass volume ratio of 1g:4mL to the dispersion, and then dried at 35°C to obtain a microporous layer; then one portion of the dispersion is taken, and 3.5wt.% of lignite humic acid is sprayed into the dispersion, stirred evenly to obtain a mixed liquid, and the microspheres are wrapped in a mass volume ratio of 1g:6mL to the mixed liquid, and then dried at 50°C to obtain a transition layer; finally, the remaining dispersion and 3.5wt.% of cellulose in the dispersion are taken and wrapped on the surface of the transition layer, and the microspheres are wrapped in a mass volume ratio of 1g:10mL to the mixed liquid, and finally dried at 24°C to obtain a macroporous layer; the dispersion is obtained by mixing titanium gel, dispersant and solvent in a weight ratio of 1.0:2.5:6.

[0079] Example 14: Different from Example 12, the microspheres are wrapped on the surface of the microspheres in a mass volume ratio of 1g:5mL to the dispersion, and then dried at 40°C to obtain a microporous layer; then one portion of the dispersion is taken, and 4.5wt.% of lignite humic acid is sprayed into the dispersion, stirred evenly to obtain a mixed liquid, and the microspheres are wrapped in a mass volume ratio of 1g:7mL to the mixed liquid, and then dried at 55°C to obtain a transition layer; finally, the remaining dispersion and 4.5wt.% of cellulose in the dispersion are taken and wrapped on the surface of the transition layer, and the microspheres are wrapped in a mass volume ratio of 1g:11mL to the mixed liquid, and finally dried at 26°C to obtain a macroporous layer; the dispersion is obtained by mixing titanium gel, dispersant and solvent in a weight ratio of 1.2:3:7.

[0080] Example 15: Different from Example 13, in step S2-1, the activation treatment method is: put the activated carbon microspheres coated with the dispersion into a preheating tank at 70°C for preheating treatment for 15 minutes, then transfer the preheated microspheres to an activation furnace, and pass 750°C water vapor into the activation furnace in an oxygen-free environment. After activation treatment for 50 minutes, cool to room temperature in a nitrogen atmosphere.

[0081] Example 16: Different from Example 13, in step S2-1, the activation treatment method is: put the activated carbon microspheres coated with the dispersion into a preheating tank at 75°C for preheating for 10 minutes, then transfer the preheated microspheres to an activation furnace, and pass 850°C water vapor into the activation furnace in an oxygen-free environment. After activation treatment for 30 minutes, cool to room temperature in an argon atmosphere.

[0082] Example 17: Different from Example 13, S2-2, a SiO2 layer with a thickness of 0.03 μm is coated on the surface of the swelling activated carbon microspheres to obtain reusable activated carbon.

[0083] Example 18: Different from Example 13, S2-2, a SiO2 layer with a thickness of 0.05 μm is coated on the surface of the swelling activated carbon microspheres to obtain reusable activated carbon.

[0084] Example 19: Different from Example 13, in step S3, 35% of solid bacterial agent, 15% of microbial extracellular polysaccharide, 10% of volcanic rock powder with a particle size of 15 to 20 nm and the rest of deionized water are mixed by mass percentage to obtain an attachment liquid.

[0085] Example 20: Different from Example 13, in step S3, 40% of solid bacterial agent, 20% of microbial extracellular polysaccharide, 12% of volcanic rock powder with a particle size of 15 to 120 nm and the rest of deionized water are mixed by mass percentage to obtain an attachment liquid.

[0086] Example 21: Different from Example 13, in step S3, the immersion time is 13 minutes, the thickness is 30 nm, and after the immersion is completed, the carrier is taken out and dried at 30°C; wherein the volume ratio of the steam to the activated carbon-microorganism composite carrier is 3:2.

[0087] Example 22: Different from Example 13, in step S3, the immersion time is 15 minutes, the thickness is 40 nm, and after the immersion is completed, the carrier is taken out and dried at 35°C; wherein the volume ratio of the steam to the activated carbon-microorganism composite carrier is 3:4.

[0088] Example 23: Different from Example 13, in the local immersion method of step S3, the deposition time is 30 s, the deposition temperature is 55° C., and the deposition thickness is 30 nm.

[0089] Example 24: Different from Example 13, in the local immersion method of step S3, the deposition time is 40 s, the deposition temperature is 65° C., and the deposition thickness is 40 nm.

[0090] Example 25: Different from Example 13, in the local immersion method of step S3, the parameters of ultrasonic treatment are: ultrasonic power density is 0.8 W / cm 2 , amplitude is 5nm, and time is 12s.

[0091] Example 26: Different from Example 13, in the local immersion method of step S3, the parameters of ultrasonic treatment are: ultrasonic power density is 1 W / cm 2 , amplitude is 10nm, time is 10s.

[0092] Example 27: Different from Example 13, in step S4, the desorption treatment method is: steam with a temperature of 40°C and a pressure of 0.5 MPa is passed into a container containing the activated carbon-microorganism composite carrier to be desorbed, so that the adsorbate in the activated carbon is desorbed, and the desorption time is 30 minutes. After taking out, it is dried at 55°C.

[0093] Example 28: Different from Example 13, in step S4, the desorption treatment method is: steam with a temperature of 50°C and a pressure of 0.7 MPa is introduced into a container containing the activated carbon-microorganism composite carrier to be desorbed, so that the adsorbate in the activated carbon is desorbed, and the desorption time is 20 minutes. After taking out, it is dried at 65°C.

[0094] Experimental example: The narrative basis of this experimental example is the recorded scheme in Example 1, which aims to illustrate the practical application effect of the present invention. In order to explore the influence of the parameters of each embodiment on the treatment effect of organic waste gas, the removal rate of organic waste gas treatment in Examples 1 to 28 and Control Examples 1 to 28 and the adsorption performance recovery rate of the activated carbon-microorganism composite carrier were tested respectively. In this experimental example, the organic waste gas from a chemical plant was selected for detection, and ammonia, hydrogen sulfide and other odor components were used as the main components for detection, and the average removal rate of each component was taken as the final removal rate; Among them, the ammonia concentration was measured at the air inlet: 135.9mg / m 3 , hydrogen sulfide concentration is 38.2mg / m 3 , TVOC concentration is 46.4mg / m 3 ;

[0095] The adsorption performance recovery rate is determined as follows: adsorption performance recovery rate = adsorption capacity of activated carbon-microorganism composite carrier after desorption treatment (mg / g) / adsorption capacity of original activated carbon-microorganism composite carrier (mg / g) × 100%;

[0096] Study 1: Study the effect of the preparation method of microbial agents on the treatment of organic waste gas

[0097] Control Example 1: Different from Example 1, mannitol was not added during the pretreatment process;

[0098] Comparative Example 2: Different from Example 1, no phosphate buffer solution was used for washing in the liquid submerged fermentation process;

[0099] Conclusion: Figure 1 , Figure 2It can be seen that the average removal rate of ammonia, hydrogen sulfide and TVOC in organic waste gas by the activated carbon-microorganism composite carrier prepared in Examples 1 to 9 can reach 98%, and the removal effect is best under the various parameter conditions of Example 1. By comparing Control Example 1 with Examples 1 to 3, we can see that the lack of mannitol addition in Control Example 1 limits the activation effect of Pseudomonas, thereby weakening the organic waste gas treatment effect of microorganisms. At the same time, due to the viscosity and solubility of mannitol, it is helpful to mix the solid bacterial agent, microbial extracellular polysaccharides and volcanic rock powder in water, further improving the composite effect of microorganisms on the surface of reusable activated carbon, thereby affecting the adsorption performance recovery rate of the activated carbon-microorganism composite carrier;

[0100] By comparing Control Example 2 with Example 1, Example 8, and Example 9, we can see that Control Example 2 lacks the step of washing with phosphate buffer, which affects the microbial activity in the microbial liquid inoculant and fails to improve the microbial contamination. As a result, the average removal rate of pollutants in organic waste gas is significantly reduced, further affecting the recovery rate of the adsorption performance of the activated carbon-microorganism composite carrier.

[0101] Study 2: Study the effect of dispersion packaging method and parameters on the treatment effect of organic waste gas

[0102] Comparative Example 3: Different from Example 13, the dispersion does not contain titanium gel.

[0103] Control Example 4: Different from Example 13, in step S2-2, the SiO2 layer is not coated.

[0104] Conclusion: Figure 3 , Figure 4It can be seen that the activated carbon-microorganism composite carriers prepared in Example 1 and Example 10 to Example 18 can achieve an average removal rate of 99% for ammonia, hydrogen sulfide and TVOC in organic waste gas, and by comparing Example 1 and Example 10 to Example 14, the activated carbon-microorganism composite carriers prepared in Example 12 to Example 14 have significantly improved organic waste gas removal rate and activated carbon-microorganism composite carrier adsorption performance recovery rate, and the activated carbon-microorganism composite carrier obtained under the various parameter conditions of Example 13 has the best performance effect. From the graphical comparison of Examples 10 to Example 18 and Control Example 3, it can be seen that the lack of added titanium gel in Control Example 3 leads to a weakened support effect during the preparation of activated carbon micropores, thereby reducing the stability of the activated carbon micropores. , further weakening the average removal effect of recyclable activated carbon on ammonia, hydrogen sulfide and TVOC in organic waste gas; and from the comparison of the diagrams of Control Example 4 and Examples 10 to 18, it can be seen that the lack of the step of coating the SiO2 layer in Control Example 4 causes the organic waste gas removal rate and adsorption performance recovery rate of the prepared activated carbon-microorganism composite carrier to be significantly reduced. The main reason is that the addition of silicon dioxide can improve the pore volume and pore size distribution of the activated carbon, thereby improving its adsorption efficiency; the swellable activated carbon microspheres coated with silicon dioxide can maintain their performance in multiple cycles due to the chemical stability and heat resistance of their surface, thereby improving the reuse performance. At the same time, the use of activated carbon microspheres coated with silicon dioxide can also help reduce the environmental release of harmful substances.

[0105] Study 3: Study the effect of the preparation method of activated carbon-microorganism composite carrier on the treatment effect of organic waste gas

[0106] Comparative Example 5: Different from Example 13, the attachment liquid does not contain volcanic rock powder.

[0107] Comparative Example 6: Different from Example 13, the attachment liquid is completely immersed in the surface of the reusable activated carbon.

[0108] Conclusion: Figure 5 , Figure 6It can be seen from the graphical results of Example 13, Example 19 to Example 26 and Control Example 5 that in Control Example 5, the mixing effect of the microbial agent is weakened due to the lack of volcanic rock powder, thereby reducing the attachment effect of the attachment liquid on the surface of the reusable activated carbon, further weakening the removal effect of the prepared activated carbon-microorganism composite carrier on organic waste gas and the adsorption performance recovery rate of the reusable activated carbon; it can be concluded that volcanic rock powder can provide a three-dimensional support structure in the microbial solution, increase the specific surface area of ​​the microorganism, promote the adsorption and growth of the microorganism, further improve the adhesion and activity of the microorganism, optimize the growth environment of the microorganism, and enhance the microorganism's ability to remove pollutants; From the graphical results of Example 13, Example 19 to Example 26 and Control Example 6, it can be seen that the activated carbon-microorganism composite carrier prepared by directly wrapping the attachment liquid completely on the surface of the reusable activated carbon in Control Example 6 has limited recovery rate of the adsorption performance of the activated carbon, and more obviously, the treatment effect of the organic waste gas shows a significant downward trend. The above situation mainly occurs because the wrapping of the activated carbon by the microbial composite film affects the treatment of the organic waste gas by the activated carbon. At the same time, since the microbial film is completely wrapped on the surface of the activated carbon, the film can only be breathable on one side, which weakens the breathability effect, thereby affecting the growth and metabolism of the microorganisms, and further reducing the treatment effect of the organic waste gas.

Claims

1. A method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms, characterized in that: The following steps are involved: S1. Preparation of microbial inoculants The Pseudomonas proteus strain is taken out and pretreated to obtain activated bacteria; the activated bacteria are inoculated into a beef extract peptone medium at a volume ratio of 2.5-3.5% for low-density fermentation treatment, and then the activated bacteria after the low-density fermentation treatment are inoculated into an LB medium at a volume ratio of 4.2-6.2% for liquid deep fermentation treatment to obtain a liquid bacterial agent, and finally the liquid bacterial agent obtained by the fermentation is dried and crushed to obtain a solid bacterial agent; S2. Preparation of reusable activated carbon S2-1, coating the surface of activated carbon microspheres with a diameter of 250-450nm with a dispersion, wherein the coating method of the dispersion is layered coating, wherein the dispersion, the dispersion and lignite humic acid accounting for 2.5-4.5wt.% of the dispersion, and the dispersion and cellulose accounting for 2.5-4.5wt.% of the dispersion are coated layer by layer in sequence, and the coating thickness is 20-30nm. After the coating is completed, an activation treatment is performed for 4-6min and a drying treatment is performed at 35-40°C for 2-3min to obtain swollen activated carbon microspheres; the dispersion is obtained by mixing titanium gel, a dispersant and a solvent in a weight ratio of 0.8-1.2:2-3:5-7; the dispersant is polystyrene or polyvinyl pyridine; S2-2, coating a SiO2 layer with a thickness of 0.03-0.05 μm on the surface of the swelling activated carbon microspheres to obtain reusable activated carbon; S3. Preparation of activated carbon-microorganism composite carrier In percentage by mass, 35-40% of solid bacterial agent, 15-20% of microbial extracellular polysaccharide, 10-12% of volcanic rock powder and 28-40% of deionized water are mixed to obtain an attachment liquid, and then the attachment liquid is used to partially impregnate the reusable activated carbon prepared in step S2-2, so that the attachment liquid is half-wrapped on the surface of the reusable activated carbon, the impregnation time is 13-15 minutes, the thickness is 30-40 nm, and after the impregnation is completed, it is taken out and dried at 30-35° C. to obtain an activated carbon-microorganism composite carrier; S4. Treatment of organic waste gas The activated carbon-microorganism composite carrier prepared in step S3 is placed in a container, and then the organic waste gas to be treated is introduced into the container. After reacting for 2 to 5 hours until the treatment is completed, the activated carbon-microorganism composite carrier is taken out and desorbed for reuse.

2. The method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms as claimed in claim 1, characterized in that: In step S1, the pretreatment method is: adding mannitol accounting for 2.5-4.5 wt.% of the Pseudomonas proteus strain at a rate of 2-3 mL / min, and then culturing at a temperature of 28-32° C. for 24-36 hours.

3. The method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms as claimed in claim 1, characterized in that: In step S1, the culture temperature of the low-density fermentation treatment is 30-35° C., the oscillation speed is 80-160 r / min, the culture time is 30-40 h, and after the culture is completed, the culture solution is centrifuged at a speed of 7000-9000 r / min for 8-12 min, and the supernatant is discarded; The method for liquid deep fermentation treatment is: first, oscillating culture is carried out for 15 to 20 hours at a temperature of 20 to 25° C. and an oscillating speed of 300 to 500 r / min, and after the oscillating culture is completed, it is washed 2 to 4 times with a phosphate buffer, and the washing liquid is used as a bacterial suspension; then, sterile air is passed through the bacterial suspension to a pressure of 0.03 to 0.05 MPa, a temperature of 28 to 38° C., a rotation speed of 180 to 220 r / min, and dissolved oxygen ≥18%, and the culture is continued for 4 to 8 hours to obtain a liquid bacterial agent.

4. The method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms as claimed in claim 1, characterized in that: In step S2-1, the layered wrapping includes the following steps: (1) Divide the dispersion into 3 to 4 equal parts; (2) Adding activated carbon microspheres to one of the dispersions, wrapping the activated carbon microspheres on the surface of the activated carbon microspheres in a mass volume ratio of 1 g: 3-5 mL of the dispersion, taking out and drying at 30-40°C to obtain a microporous layer; then taking out one of the dispersions, spraying 2.5-4.5 wt.% of lignite humic acid into the dispersion, stirring evenly to obtain a mixed solution, wrapping the activated carbon microspheres on the surface of the mixed solution in a mass volume ratio of 1 g: 5-7 mL, and then drying at 45-55°C to obtain a transition layer; finally, taking the remaining dispersion and cellulose in a mass volume ratio of 2.5-4.5 wt.% of the dispersion, wrapping the activated carbon microspheres on the surface of the transition layer in a mass volume ratio of 1 g: 9-11 mL, and finally drying at 22-26°C to obtain a macroporous layer; wherein the pore size of the microporous layer is less than the pore size of the transition layer and less than the pore size of the macroporous layer; the pore size of the macroporous layer is 6-10 nm.

5. The method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms as claimed in claim 4, characterized in that: The solvent is amyl alcohol or cyclopentanone.

6. The method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms as claimed in claim 1, characterized in that: In step S2-1, the activation treatment method is: placing the activated carbon microspheres coated with the dispersion in a preheating tank at 70-75°C for preheating treatment for 10-15 minutes, then transferring the preheated activated carbon microspheres to an activation furnace, and passing 750-850°C water vapor into the activation furnace in an oxygen-free environment. After the activation treatment for 30-50 minutes, the microspheres are cooled to room temperature in a nitrogen or argon atmosphere.

7. The method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms as claimed in claim 1, characterized in that: In step S3, the local impregnation method is: suspending the reusable activated carbon in the attachment liquid, and chemically depositing the attachment liquid on the surface of the bottom of the reusable activated carbon through ultrasonic treatment to form a thin film, the deposition time is 30~40s, the deposition temperature is 55~65℃, and the deposition thickness is 30~40nm.

8. The method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms as claimed in claim 7, characterized in that: The parameters of the ultrasonic treatment are: ultrasonic power density is 0.8~1W / cm 2 , amplitude is 5~10nm, and time is 10~12s.

9. The method for treating organic waste gas based on the combination of high-efficiency activated carbon and microorganisms as claimed in claim 1, characterized in that: In step S4, the desorption treatment method is: steam with a temperature of 40~50°C and a pressure of 0.5~0.7MPa is passed into a container containing the activated carbon-microorganism composite carrier to be desorbed, so that the adsorbate in the activated carbon is desorbed, and the desorption time is 20~30min. After taking out, it is dried at 55~65°C; wherein the volume ratio of the steam to the activated carbon-microorganism composite carrier is 3:2~4.

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