A method for treating VOCs in sewage

Abstract

The present invention relates to the field of sewage treatment, and in particular to a method for treating VOCs in sewage. The method comprises: using a special microbial degradation method, adding an active bacterial agent to the target sewage for aeration treatment; the active bacterial agent is prepared by the following method: (1) mixing an aromatic acid and an inorganic salt in water, adjusting the pH value to a weak acidity, stirring the reaction to obtain a precarrier, mixing the prepared precarrier with an organic metal compound and placing it in a salt solution, stirring the reaction, filtering, washing and drying to obtain a carrier; (2) mixing a microbial capsule with the carrier in water, and aerating the mixture under light conditions to obtain an active bacterial agent. The present invention breaks the metabolic activity limitation of volatile organic compounds by constructing a bioelectrochemical system and the synergistic effect between microorganisms, and ensures the metabolic activity of the microbial system in sewage by using a special microbial carrier, and ensures the survival rate of the microbial agent in the sewage environment in a multi-stage domestication manner.

Description

Technical Field

[0001] The present invention relates to the field of sewage treatment, and in particular to a method for treating VOCs in sewage. Background Art

[0002] With the rapid development of industrialization in my country, people have paid more attention to the quality of the air environment in recent years. The volatile organic compounds emitted have caused serious pollution to the air quality and posed a huge threat to human survival. Therefore, the control technology of volatile organic compounds has become one of the research hotspots of scholars at home and abroad.

[0003] The basic principle of VOCs biological treatment technology is to oxidize and decompose most organic waste gases into small-molecule inorganic substances such as water and carbon dioxide during the growth and metabolism of microorganisms, and a very small number of them will be converted into microbial cytoplasmic organisms. Biological purification technology is more suitable for treating volatile organic compound waste gases with lower concentrations. Compared with other previous technologies, this technology has the advantages of simple operating equipment, low cost, and less secondary pollution. However, the existing technical solutions have the following technical defects: (1) The area required for construction increases with the increase in waste gas concentration; (2) During the treatment, elements such as N, Cl, and S cannot be contained, otherwise the pH value in the material will change and have a certain inhibitory effect on microorganisms; (3) Bacterial culture is difficult, the survival rate is unstable, and it is greatly affected by climate. Summary of the Invention

[0004] The technical solution of the present invention addresses the technical difficulties in traditional technical solutions, such as low microbial metabolic activity, harsh microbial growth environment, and the need to further improve the removal rate of VOCs by biological methods, and provides a method for treating VOCs in sewage.

[0005] The main objectives of the present invention are:

[0006] 1. Improve the metabolic activity of microorganisms in the process of VOCs biological treatment technology;

[0007] 2. Improve the removal rate of VOCs by biological methods and break the activity limit of organisms;

[0008] 3. Improve the survival rate of microorganisms in VOCs environment.

[0009] To achieve the above objectives, the present invention adopts the following technical solutions.

[0010] A method for treating VOCs in sewage,

[0011] The method comprises: using a special microbial degradation method, adding an active bacterial agent into target wastewater containing VOCs for aeration treatment for 1 to 3 days;

[0012] The active bacterial agent is prepared by the following method:

[0013] (1) Mixing an aromatic acid and an inorganic salt in water, adjusting the pH value to a weak acid, stirring the reaction, filtering, washing, and drying to obtain a pre-carrier, mixing the prepared pre-carrier with an organometallic compound, placing the mixture in a salt solution, stirring the reaction, filtering, washing, and drying to obtain a carrier;

[0014] (2) The microbial capsules and the carrier are mixed in water and aerated under light conditions to obtain an active bacterial agent.

[0015] As a preference,

[0016] The aromatic acid in step (1) is trimesic acid;

[0017] The inorganic salt in step (1) is a soluble iron halide salt;

[0018] The mass ratio of the aromatic acid and the inorganic salt used in step (1) is 1:(2.3-2.7). When mixed in water, the amount of water used is 600-700 wt% of the total mass of the aromatic acid and the inorganic salt.

[0019] As a preference,

[0020] In the step (1), the pH value is adjusted to 5 to 6, and after the first stirring reaction for 12 to 24 hours, the pre-support is filtered, washed and dried;

[0021] The mass ratio of the pre-support to the organometallic compound in step (1) is 1:(0.45-0.55);

[0022] The organometallic compound in step (1) is manganese citrate;

[0023] The salt solution in step (1) is a 0.01-0.03 mol / L sodium chloride aqueous solution, and its amount is 300-350 wt% of the total mass of the pre-support and the organometallic compound, and the second stirring reaction is carried out for 10-12 hours.

[0024] As a preference,

[0025] The mass ratio of the microbial capsule to the carrier in step (2) is (2.8-3.2):1;

[0026] In step (2), the microbial capsules and the carrier are mixed in water with a total mass of 200 to 300 wt%, and aerated for 2 to 4 hours under natural light conditions.

[0027] As a preference,

[0028] The microbial capsules in step (2) are prepared by the following method:

[0029] (a) acclimating the microbial agent multiple times in the presence of halogenated hydrocarbons, benzene series, and organic ketones to produce a high-quality bacterial population;

[0030] (b) Proliferation and cultivation of high-quality bacterial flora and preparation of microbial capsules.

[0031] As a preference,

[0032] The microbial agent in step (a) is composed of a mixture of Corynebacterium glutamicum, Bacteroides thetaiotaomicron, Chloroflexus spp. and Acidobacterium spp., with the proportion of each component being 18-22 wt% of Corynebacterium glutamicum, 13-17 wt% of Chloroflexus spp., 9-11 wt% of Acidobacterium spp., and the balance being Bacteroides thetaiotaomicron. The concentration of the microbial agent is 3×10 11 ~5×10 11 CFU / mL.

[0033] As a preference,

[0034] The halogenated hydrocarbon in step (a) is a chlorobenzene aqueous solution with a concentration of 0.05 g / L;

[0035] The benzene series compound in step (a) is a resorcinol aqueous solution with a concentration of 2.50 g / L;

[0036] The organic ketone in step (a) is a 0.15 g / L 2,4-pentanedione aqueous solution.

[0037] As a preference,

[0038] The volume ratio of the halogenated hydrocarbon, benzene series and organic ketone in step (a) is 1:1:1. During the acclimation process, the three are added dropwise every 3 to 5 hours, and the total amount added each time is 0.6 to 1.0 mL / mL of microbial agent.

[0039] The multiple acclimation processes in step (a) are specifically as follows:

[0040] The microbial agent is proliferated and cultivated in an inorganic salt culture medium at a temperature of 27-29°C and a pH of 7.0-8.0 for 6-8 hours. Subsequently, a chlorobenzene aqueous solution, a resorcinol aqueous solution and a 2,4-pentanedione aqueous solution are added dropwise to the culture medium every 4 hours for degradation screening. The degradation screening is performed 3-5 times to cultivate a high-quality bacterial community.

[0041] As a preference,

[0042] The high-quality bacterial colony in step (b) was cultivated to a concentration of 4×10 11 ~6×10 11CFU / mL, then the inoculum containing high-quality bacterial flora and sodium alginate solution with a concentration of 5.00-5.10 mol / L were mixed evenly in a volume ratio of 1: (1.8-2.2), and calcium salt was added. The amount of calcium salt added was 25-30 wt% of the sodium alginate content in the sodium alginate solution. Then, it was mixed with 4.5-5.5 times the volume of liquid paraffin to form an oil-in-water emulsion. After adding a sedimentation agent, the sedimentation was carried out to obtain a microbial capsule;

[0043] The liquid paraffin contains 0.5 to 1.5 wt% of Span 80;

[0044] The precipitant is a 2-3 mol / L calcium chloride solution containing 0.8-1.0 wt% tween-80, and the precipitant is slowly added dropwise until the precipitate at the bottom of the solution no longer increases.

[0045] Existing biological methods for the adsorption and degradation of volatile organic compounds in wastewater hold great promise. However, the difficulty of cultivating bacteria and their low survival rates significantly limit their degradation rate, impacting the removal efficiency of single biological treatment technologies. The present invention utilizes a microbial interstellate system and a specialized carrier to create an internal electric field, ensuring both microbial survival and degradation activity.

[0046] The activity of microorganisms in sewage environment is the key parameter for biological degradation of volatile organic compounds. In the technical solution of the present invention, filamentous fungi with large specific surface area and hyphae are helpful in removing pollutants with limited mass transfer. Bacteria have a strong ability to utilize nitrogen and carbon sources in sewage environment. At the same time, the pheromones transmitted to the water environment can attract the growth of fungal hyphae. Fungi are more tolerant to acidic environment than bacteria, and bacteria have a stronger ability to neutralize and transform the environment. Therefore, the formation and growth of suspended bacterial clusters in the technical solution of the present invention can increase the mass transfer of volatile organic compounds from the gas phase to the biological phase, thereby improving the biomass of volatile organic compounds. In order to improve the survival rate of microbial agents in sewage environment, the present invention specifically attempts to use multiple groups of bacteria to build bacterial community relationships to ensure the activity of sludge. First, in most sewage systems, the water system pH shows obvious acidity or even strong acidity. As an acidophilic chemical trophic bacterium, it first grows under pH conditions of 3 to 6 and produces Esculin, which hydrolyzes β-galactosidase and catalase in the microorganisms and begins to multiply in large quantities. It can effectively degrade oxidized metals and unsaturated aromatic alkanes in the water system and begins to multiply in large quantities. When the concentration of newly proliferated acidobacillus cysts in the water system reaches 7×10 12 ~8×10 12When the CFU / mL is reached, the microorganisms begin to secrete a large amount of exopolysaccharides to the outside world. The presence of exopolysaccharides will help increase the adhesion between microbial monomers and build the skeleton of the microbial flora; then, after the initial purification of the water system by acid bacteria, the water system becomes weakly acidic. Under this condition, the acid bacteria capsule enters the decay stage of microbial growth, and Corynebacterium glutamicum and Bacteroides thetaiotaomicron form a symbiotic system. Under weak acid conditions, Corynebacterium glutamicum metabolizes the organic components in the water system mainly into acetylglutamine. At the same time, the pheromones released to the outside world can stimulate the formation of the outer membrane vesicle structure of Bacteroides thetaiotaomicron, which helps Bacteroides thetaiotaomicron decompose the organic components in the water system. The metabolic products of other microorganisms, such as complex polysaccharides, proteins and lipids, are used to initially construct the bacterial cluster system. Finally, without a complete C, N and O cycle, the bacterial cluster system cannot exist. Therefore, the technical solution of the present invention also adds Chloroflexus. In the bacterial cluster system, Chloroflexus first absorbs the nutrients decomposed by the symbiotic system and begins to multiply in large quantities. It constructs different forms according to the specific water environment and forms multiple metabolic pathways. The operation mode can not only construct a complete chemical cycle process of a series of important biogenic elements such as C, N, O, better participate in the ecological construction process of microorganisms, but also help the microbial cluster to adapt to the environment and its evolution.

[0047] The technical solution of the present invention uses the mechanical movement of microbial growth and metabolism to resist entropy, prevent the decay of the bacterial mass in which the microorganisms themselves are located, and achieve balance through the transmission of pheromones and genetic factors, thereby reaching the stable period of the microbial growth curve. In a system such as a sewage environment, microorganisms maintain the activity of the bacterial mass through continuous metabolism and proliferation, converting volatile organic compounds and inorganic particles into biological phases and capturing them.

[0048] Maintaining the stability of the bacterial consortium system. Changes in external conditions (such as temperature, pH, nutrient deficiencies, etc.) and shock loads can affect the stability of the consortium. Fluctuations in flow and concentration, which occur in actual industry, are key factors affecting microbial removal performance. Due to their growth characteristics, microorganisms can maintain removal performance under stable conditions. However, sudden changes in the wastewater system can exceed their resistance, prolonging their adaptation time and resulting in poor purification results or even microbial death. The technical solution of the present invention is to autonomously screen and protect benign mutations in the consortium, and to achieve this goal through the preparation and use of special carriers. The present invention selects to use metal organic matter as a bacterial agent carrier. On the one hand, the metal organic matter prepared by the scheme of the present invention can act as a photocatalyst to promote the reaction of intolerant volatile organic matter in the sewage system into hydrophilic volatile organic matter or soluble organic matter, which is beneficial to the degradation treatment of microorganisms. The photocatalyst causes an increase in the capture of photogenerated electrons, produces more active free radicals, and increases the reaction free radicals, thereby accelerating the photocatalytic performance. The radiation of light excites the carrier material to generate electron-hole pairs. The electrons absorb the energy of photons and jump from the valence band to the conduction band, leaving corresponding holes in the valence band. The electrons and holes participate in the redox reaction of strong oxidizing free radicals in the water system and are converted into active oxides, thereby decomposing the volatile organic matter into carbon dioxide, water and soluble organic matter. On the other hand, due to the special structure of the carrier material itself as a heterogeneous For photocatalysts, before light irradiation, electrons near the metal interface tend to diffuse into the organic skeleton, making the metal positively charged. At the same time, holes on trimesic acid tend to diffuse into the metal interface, leaving a negative charge. As electrons and holes continue to diffuse until the Fermi level of the system reaches equilibrium, an electronically active space will be formed at the interface between the carrier material and the microorganism. Under light conditions, photoelectrons and holes, under the influence of the electronically active space, migrate to the conduction band of the metal interface and the valence band of the organic skeleton, respectively, thereby obtaining spatial separation of photogenerated electron-hole pairs and generating an internal electric field with the microbial flora. Metal ion doping can not only become a capture trap for photogenerated electron-hole pairs, but also cause defects in the carrier material lattice to make electron transfer more likely and reduce the activation energy barrier for conversion.

[0049] In this technical solution, the active substances produced by photocatalytic decomposition promote microbial growth. This improves system performance by constructing a bioelectrochemical system that couples bioelectrolysis with biotrickling filtration and the synergistic effects between microorganisms. Under weak electrical stimulation, the metabolic activity of oxygenases and dehalogenases in the microbial flora is significantly enhanced, strengthening the microbial flora's ability to degrade aromatic organic compounds through ring-opening reactions and enhancing the microbial redox reactions on volatile organic compounds.

[0050] The advantages of the present invention are:

[0051] (1) The present invention breaks the metabolic activity limitation of volatile organic compounds by constructing a bioelectrochemical system and the synergistic effect between microorganisms;

[0052] (2) The technical solution of the present invention ensures the metabolic activity of the microbial system in sewage by using special microbial carriers;

[0053] (3) The present invention uses a multi-stage domestication method to ensure the survival rate of microbial agents in sewage environments. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below are generally only a portion of the embodiments of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0055] Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all methods known to those skilled in the art.

[0056] Example 1: A method for treating VOCs in sewage.

[0057] The method comprises:

[0058] (1) A mixture of 18 wt% of Corynebacterium glutamicum, 13 wt% of Chloroflexus, 9 wt% of Acidobacterium cysts and the remainder of Bacteroides thetaiotaomicron was prepared at a concentration of 3×10 11 A microbial inoculum with a CFU / mL was cultured in an inorganic salt culture medium at 27°C and a pH of 7.0 for 8 h. Subsequently, 1.0 mL of a 0.05 g / L chlorobenzene aqueous solution, 1.0 mL of a 2.50 g / L resorcinol aqueous solution, and 1.0 mL of a 0.15 g / L 2,4-pentanedione aqueous solution were added dropwise to the culture medium every 4 h. Degradation screening was performed three times to cultivate a high-quality bacterial population, and multiple acclimation tests were performed to obtain a high-quality bacterial population.

[0059] (2) High-quality bacterial flora were cultured to a concentration of 4×10 11CFU / mL and the concentration difference value is less than 5%, and microbial capsules are prepared. The specific preparation method is as follows: the mixed high-quality bacterial agent and a sodium alginate solution with a concentration of 5.05 mol / L are mixed evenly in a volume ratio of 1:1.8, and then calcium salt is added, and the amount of calcium salt added is 25 wt% of the sodium alginate content in the sodium alginate solution. Subsequently, it is mixed with 4.5 times the volume of liquid paraffin to form an oil-in-water emulsion, and a sedimentation agent is added and precipitated to obtain microbial capsules, wherein the liquid paraffin contains 0.5 wt% of Span 80, and the sedimentation agent is a 2 mol / L calcium chloride solution containing 0.8 wt% of tween-80. The sedimentation agent is slowly added dropwise until the sediment at the bottom of the solution no longer increases.

[0060] (3) 98% pure trimesic acid and 45% pure ferric chloride solution were mixed evenly in a mass ratio of 1:2.3, and 600 wt% of the mass of the mixture of trimesic acid and ferric chloride solution was added to deionized water, and 1.0 mol / L sodium hydroxide solution was used to adjust the pH to 5. The mixture was stirred for 12 h, washed and dried to obtain a prefabricated carrier. The prefabricated carrier was mixed evenly with 90% manganese citrate (wherein the concentration of silver nitrate was ≤0.02 mol / L) in a mass ratio of 1:0.45, and 300 wt% of the mass of the mixture of the prefabricated carrier and manganese citrate and 0.01 mol / L sodium chloride solution were mixed into the mixture, stirred for 10 h, washed and dried to obtain a carrier.

[0061] (4) The microbial capsules and the carrier were mixed evenly at a mass ratio of 2.8:1, and 200 wt% of the mass of the mixture of microbial capsules and the carrier was added into the mixture. The mixture was aerated for 2 h under natural light conditions to obtain an active bacterial agent.

[0062] Industrial wastewater discharged from petroleum refining and petrochemical enterprises was treated by adding the prepared active bacterial agent to the aeration tank at a ratio of 20 mL per cubic meter of wastewater. The performance of the industrial wastewater after wastewater treatment (aeration for 3 days) was tested in a natural environment. The specific test items are as follows.

[0063] VOCs removal rate: VOCs removal rate = 100% - (VOCs content in industrial wastewater after treatment / VOCs content in industrial wastewater before treatment) × 100%.

[0064] Suspended solids concentration in the water system: The mass of suspended solids per unit volume of mixed liquid in the aeration tank. Take 25 mL of water sample and dilute it to 50 mL with distilled water. Turn on the 3S-TR80 suspended solids / turbidity analyzer for testing. Measure three times and take the average value to calculate the suspended solids concentration in the water system. The specific calculation formula is:

[0065] Suspended solids concentration = n × Mss

[0066] Where: n——distilled water dilution multiple;

[0067] Mss - the average of three 3S-TR80 suspended solids / turbidity analyzer readings.

[0068] Volatile suspended solids: Take 100 mL of sludge from the sedimentation tank and centrifuge it at 4500 rpm for 10 minutes. Transfer the solid portion of the sludge to a crucible after centrifugation. Place it in an oven and dry it at 105°C to a constant weight. Then place it in a muffle furnace and burn it at 600°C until the mass no longer changes. Weigh the ash content and calculate VSS. The specific details are as follows: .

[0069] Where: VSS - Volatile Suspended Solids, mg / L;

[0070] TSS - total suspended solids, the amount of solids remaining after evaporation of suspended solids after centrifugation, mg;

[0071] M0——mass of ash, mg.

[0072] Sludge volume index: The volume of wet sludge formed per unit mass of dry sludge after the mixed liquid in the aeration tank has settled for 30 minutes. Take 1 L of mixed test sample liquid at the outlet of the aeration tank, measure the suspended solids concentration, pour the mixed test sample liquid into a 2000 mL graduated cylinder, and let it stand for 30 minutes. The volume ratio of the settled sludge to the mixed test sample liquid is the sludge settling volume. Calculate the sludge volume index according to the following formula: .

[0073] Where: SVI - sludge volume index;

[0074] SV%——sludge settling volume, mL / L;

[0075] MLSS - suspended solids concentration, g / L.

[0076]

[0077] In addition, the treated water system was observed, and the microbial activity (Ma), microbial self-oxidation residues (Me), organic matter adsorbed on the carrier that was not degraded by microorganisms (Mi) and inorganic suspended solids (Mii) in the water system were observed using an electron microscope. The color of the sediment in the water system was observed, and the types, quantity and metabolic activity of microbial flora in the solid sediment of industrial drainage were observed using an electron microscope. The inventors discovered that the active bacterial agent prepared in the embodiment of the present invention can effectively form a flocculent precipitate with high microbial activity and stable structure during the sewage treatment process, and then form activated sludge with the inorganic components in the sewage. The activated sludge is tea-brown in color, and the active microorganisms exist in the form of bacterial flocs, which improves the bacteria's resistance to adverse growth factors in the external environment. The polysaccharide metabolites secreted during microbial growth can coat the organic and inorganic components in the sewage system to form sticky clumps, which not only enhances the adsorption effect of the carrier, but also provides nitrogen and carbon sources for the microbial flora. The inventors observed that the active bacterial flora adsorbed VOCs in the sewage system very quickly, and the adsorption process could be completed in about 20 minutes with strong stability. The concentration of suspended organic matter in the treated discharge water was very high, indicating that the bacterial flora had a strong adsorption effect. At the same time, the sludge in the sedimentation tank and the return sludge generated by the aeration tank still contained a large number of active microorganisms and could be re-entered into the aeration tank for industrial sewage treatment.

[0078] Example 2: A method for treating VOCs in sewage.

[0079] The method comprises:

[0080] (1) A mixture of 20 wt% of Corynebacterium glutamicum, 15 wt% of Chloroflexus, 10 wt% of Acidobacterium cysts and the remainder of Bacteroides thetaiotaomicron was prepared at a concentration of 4×10 11 A microbial inoculum with a CFU / mL was cultured in an inorganic salt culture medium at 28°C and a pH of 7.5 for 7 h. Subsequently, 1.0 mL of a 0.05 g / L chlorobenzene aqueous solution, 1.0 mL of a 2.50 g / L resorcinol aqueous solution, and 1.0 mL of a 0.15 g / L 2,4-pentanedione aqueous solution were added dropwise to the culture medium every 4 h. Degradation screening was performed four times to cultivate a high-quality bacterial population, and multiple acclimation tests were performed to obtain a high-quality bacterial population.

[0081] (2) High-quality bacterial flora were cultured to a concentration of 5×10 11CFU / mL and the concentration difference value is less than 5%, and microbial capsules are prepared. The specific preparation method is as follows: the mixed high-quality bacterial agent and a sodium alginate solution with a concentration of 5.05 mol / L are mixed evenly in a volume ratio of 1:2, and then calcium salt is added, and the amount of calcium salt added is 27 wt% of the sodium alginate content in the sodium alginate solution. Subsequently, it is mixed with 5 times the volume of liquid paraffin to form an oil-in-water emulsion, and a sedimentation agent is added and precipitated to obtain microbial capsules, wherein the liquid paraffin contains 1 wt% of Span 80, and the sedimentation agent is a 2.5 mol / L calcium chloride solution containing 0.9 wt% of tween-80. The sedimentation agent is slowly added dropwise until the sediment at the bottom of the solution no longer increases.

[0082] (3) 98% pure trimesic acid and 45% pure ferric chloride solution were mixed evenly in a mass ratio of 1:2.5, and 650 wt% of the mass of the mixture of trimesic acid and ferric chloride solution was added to deionized water, and the pH was adjusted to 5.5 using 1.0 mol / L sodium hydroxide solution. The mixture was stirred for 18 hours, washed and dried to obtain a prefabricated carrier. The prefabricated carrier was mixed evenly with 90% manganese citrate (wherein the concentration of silver nitrate was ≤0.02 mol / L) in a mass ratio of 1:0.45, and 300 wt% of the mass of the mixture of the prefabricated carrier and manganese citrate and 0.01 mol / L sodium chloride solution were mixed in. The mixture was stirred for 10 hours, washed and dried to obtain a carrier.

[0083] (4) The microbial capsules and the carrier were mixed evenly in a mass ratio of 3:1, and 250 wt% of the mass of the mixture of microbial capsules and the carrier was added into the mixture. The mixture was aerated for 3 h under natural light conditions to obtain an active bacterial agent.

[0084] Industrial wastewater discharged from petroleum refining and petrochemical enterprises was treated as in Example 1. The prepared active bacterial agent was added to the aeration tank at a ratio of 20 mL per cubic meter of wastewater. The performance of the industrial wastewater after wastewater treatment (aeration for 3 days) was tested in a natural environment. The specific test items are as follows.

[0085] VOCs removal rate: VOCs removal rate = 100% - (VOCs content in industrial wastewater after treatment / VOCs content in industrial wastewater before treatment) × 100%.

[0086] Suspended solids concentration in the water system: The mass of suspended solids per unit volume of mixed liquid in the aeration tank. Take 25 mL of water sample and dilute it to 50 mL with distilled water. Turn on the 3S-TR80 suspended solids / turbidity analyzer for testing. Measure three times and take the average value to calculate the suspended solids concentration in the water system. The specific calculation formula is:

[0087] Suspended solids concentration = n × Mss

[0088] Where: n——distilled water dilution multiple;

[0089] Mss - the average of three 3S-TR80 suspended solids / turbidity analyzer readings.

[0090] Volatile suspended solids: Take 100 mL of sludge from the sedimentation tank and centrifuge it at 4500 rpm for 10 minutes. Transfer the solid portion of the sludge to a crucible after centrifugation. Place it in an oven and dry it at 105°C to a constant weight. Then place it in a muffle furnace and burn it at 600°C until the mass no longer changes. Weigh the ash content and calculate VSS. The specific details are as follows: .

[0091] Where: VSS - Volatile Suspended Solids, mg / L;

[0092] TSS - total suspended solids, the amount of solids remaining after evaporation of suspended solids after centrifugation, mg;

[0093] M0——mass of ash, mg.

[0094] Sludge volume index: The volume of wet sludge formed per unit mass of dry sludge after the mixed liquid in the aeration tank has settled for 30 minutes. Take 1 L of mixed test sample liquid at the outlet of the aeration tank, measure the suspended solids concentration, pour the mixed test sample liquid into a 2000 mL graduated cylinder, and let it stand for 30 minutes. The volume ratio of the settled sludge to the mixed test sample liquid is the sludge settling volume. Calculate the sludge volume index according to the following formula: .

[0095] Where: SVI - sludge volume index;

[0096] SV%——sludge settling volume, mL / L;

[0097] MLSS - suspended solids concentration, g / L.

[0098]

[0099] In addition, the treated water system was observed using an electron microscope to measure microbial activity (Ma), microbial oxidation residues (Me), organic matter adsorbed on the carrier and not degraded by the microorganisms (Mi), and inorganic suspended solids (Mii). The color of the sediment in the water system was also observed. Furthermore, the types, numbers, and metabolic activity of microbial flora in the solid sediment of industrial wastewater were also observed using an electron microscope. The inventors found that the active bacterial agent prepared in this example can achieve good adsorption and sedimentation performance.

[0100] Example 3: A method for treating VOCs in sewage,

[0101] The method comprises:

[0102] (1) A mixture of 22 wt% of Corynebacterium glutamicum, 17 wt% of Chloroflexus, 11 wt% of Acidobacterium cysts and the remainder of Bacteroides thetaiotaomicron was prepared at a concentration of 5×10 11 A microbial inoculum with a CFU / mL was cultured in an inorganic salt culture medium at 29°C and pH 8.0 for 6 h. Subsequently, 1.0 mL of a 0.05 g / L chlorobenzene aqueous solution, 1.0 mL of a 2.50 g / L resorcinol aqueous solution, and 1.0 mL of a 0.15 g / L 2,4-pentanedione aqueous solution were added dropwise to the culture medium every 4 h. Degradation screening was performed five times to cultivate a high-quality bacterial population, and multiple acclimation tests were performed to obtain a high-quality bacterial population.

[0103] (2) High-quality bacterial colonies were grown to a concentration of 6×10 11 CFU / mL and a concentration difference value of <5%, and preparing microbial capsules, specifically preparing the following method: the mixed high-quality bacterial agent and a sodium alginate solution with a concentration of 5.05 mol / L are mixed evenly in a volume ratio of 1:2.2, and then calcium salt is added, and the amount of calcium salt added is 30 wt% of the sodium alginate content in the sodium alginate solution, and then mixed with 5.5 times the volume of liquid paraffin to form an oil-in-water emulsion, and a sedimentation agent is added and precipitated to obtain microbial capsules, wherein the liquid paraffin contains 1.5 wt% of Span 80, and the sedimentation agent is a 3 mol / L calcium chloride solution containing 1.0 wt% of tween-80, and the sedimentation agent is slowly added dropwise until the sediment at the bottom of the solution no longer increases;

[0104] (3) 98% pure trimesic acid and 45% pure ferric chloride solution were mixed evenly in a mass ratio of 1:2.7, and 700 wt% of the mass of the mixture of trimesic acid and ferric chloride solution was added to deionized water, and 1.0 mol / L sodium hydroxide solution was used to adjust the pH to 6. The mixture was stirred for 24 hours, washed and dried to obtain a prefabricated carrier. The prefabricated carrier was mixed evenly with 90% manganese citrate (wherein the concentration of silver nitrate was ≤0.02 mol / L) in a mass ratio of 1:0.45, and 300 wt% of the mass of the mixture of the prefabricated carrier and manganese citrate and 0.01 mol / L sodium chloride solution were mixed into the mixture, and the mixture was stirred for 10 hours, washed and dried to obtain a carrier.

[0105] (4) The microbial capsules and the carrier were mixed evenly at a mass ratio of 3.2:1, and 300 wt% of the mass of the mixture of microbial capsules and the carrier was added into the mixture. The mixture was aerated under natural light for 4 h to obtain an active bacterial agent.

[0106] Industrial wastewater discharged from petroleum refining and petrochemical enterprises was treated as in Example 1. The prepared active bacterial agent was added to the aeration tank at a ratio of 20 mL per cubic meter of wastewater. The performance of the industrial wastewater after wastewater treatment (aeration for 3 days) was tested in a natural environment. The specific test items are as follows.

[0107] VOCs removal rate: VOCs removal rate = 100% - (VOCs content in industrial wastewater after treatment / VOCs content in industrial wastewater before treatment) × 100%.

[0108] Suspended solids concentration in the water system: The mass of suspended solids per unit volume of mixed liquid in the aeration tank. Take 25 mL of water sample and dilute it to 50 mL with distilled water. Turn on the 3S-TR80 suspended solids / turbidity analyzer for testing. Measure three times and take the average value to calculate the suspended solids concentration in the water system. The specific calculation formula is:

[0109] Suspended solids concentration = n × Mss

[0110] Where: n——distilled water dilution multiple;

[0111] Mss - the average of three 3S-TR80 suspended solids / turbidity analyzer readings.

[0112] Volatile suspended solids: Take 100 mL of sludge from the sedimentation tank and centrifuge it at 4500 rpm for 10 minutes. Transfer the solid portion of the sludge to a crucible after centrifugation. Place it in an oven and dry it at 105°C to a constant weight. Then place it in a muffle furnace and burn it at 600°C until the mass no longer changes. Weigh the ash content and calculate VSS. The specific details are as follows: .

[0113] Where: VSS - Volatile Suspended Solids, mg / L;

[0114] TSS - total suspended solids, the amount of solids remaining after evaporation of suspended solids after centrifugation, mg;

[0115] M0——mass of ash, mg.

[0116] Sludge volume index: The volume of wet sludge formed per unit mass of dry sludge after the mixed liquid in the aeration tank has settled for 30 minutes. Take 1 L of mixed test sample liquid at the outlet of the aeration tank, measure the suspended solids concentration, pour the mixed test sample liquid into a 2000 mL graduated cylinder, and let it stand for 30 minutes. The volume ratio of the settled sludge to the mixed test sample liquid is the sludge settling volume. Calculate the sludge volume index according to the following formula: .

[0117] Where: SVI - sludge volume index;

[0118] SV%——sludge settling volume, mL / L;

[0119] MLSS - suspended solids concentration, g / L.

[0120]

[0121] In addition, the treated water system was observed using an electron microscope to measure microbial activity (Ma), microbial oxidation residues (Me), organic matter adsorbed on the carrier and not degraded by the microorganisms (Mi), and inorganic suspended solids (Mii). The color of the sediment in the water system was also observed. Furthermore, the types, numbers, and metabolic activity of microbial flora in the solid sediment of industrial wastewater were also observed using an electron microscope. The inventors found that the active bacterial agent prepared in this example can achieve good adsorption and sedimentation performance.

[0122] Comparative Example 1: A method for treating VOCs in sewage. The specific preparation method is the same as that of Example 2, except that the unique multi-stage acclimation method of the present invention is not used. The specific operation is as follows:

[0123] (1) A mixture of 20 wt% of Corynebacterium glutamicum, 15 wt% of Chloroflexus, 10 wt% of Acidobacterium cysts and the remainder of Bacteroides thetaiotaomicron was prepared at a concentration of 4×10 11 The microbial inoculum was cultured to a concentration of 5×10 11 CFU / mL and the concentration difference value is less than 5%, and microbial capsules are prepared. The specific preparation method is as follows: the mixed high-quality bacterial agent and a sodium alginate solution with a concentration of 5.05 mol / L are mixed evenly in a volume ratio of 1:2, and then calcium salt is added, and the amount of calcium salt added is 27 wt% of the sodium alginate content in the sodium alginate solution. Subsequently, it is mixed with 5 times the volume of liquid paraffin to form an oil-in-water emulsion, and a sedimentation agent is added and precipitated to obtain microbial capsules, wherein the liquid paraffin contains 1 wt% of Span 80, and the sedimentation agent is a 2.5 mol / L calcium chloride solution containing 0.9 wt% of tween-80. The sedimentation agent is slowly added dropwise until the sediment at the bottom of the solution no longer increases.

[0124] (2) 98% pure trimesic acid and 45% pure ferric chloride solution were mixed in a mass ratio of 1:2.5, and 650 wt% of the mass of the mixture of trimesic acid and ferric chloride solution was added to deionized water, and the pH was adjusted to 5.5 using 1.0 mol / L sodium hydroxide solution. The mixture was stirred for 18 hours, washed and dried to obtain a prefabricated carrier. The prefabricated carrier was mixed with 90% manganese citrate (wherein the concentration of silver nitrate was ≤0.02 mol / L) in a mass ratio of 1:0.45, and 300 wt% of the mass of the mixture of the prefabricated carrier and manganese citrate and 0.01 mol / L sodium chloride solution were mixed in. The mixture was stirred for 10 hours, washed and dried to obtain a carrier.

[0125] (3) The microbial capsules and the carrier were mixed evenly in a mass ratio of 3:1, and 250 wt% of the mass of the mixture of microbial capsules and the carrier was added into the mixture. The mixture was aerated for 3 h under natural light conditions to obtain an active bacterial agent.

[0126] The active bacterial agent prepared in the comparative example was used in the same manner as in Example 2 to treat industrial wastewater discharged from petroleum refining and petrochemical enterprises. The prepared active bacterial agent was added to the aeration tank at a ratio of 20 mL per cubic meter of wastewater. The industrial wastewater after wastewater treatment (aeration for 3 days) was partially tested in a natural environment using the same method as in Example 2. The characterization results are as follows:

[0127]

[0128] From the comparison of the above characterization results with Example 2, it was found that the suspended solids concentration, volatile suspended solids and sludge volume index in the water system formed by the active bacterial agent prepared in the comparative example were reduced to varying degrees. After research and observation by the inventors, although the activated sludge formed in the comparative example can perform simple adsorption in the sewage system, the content of organic pollutants actually degraded and adsorbed in the activated sludge is small. The unique carrier of the present invention can generate a weak electrical signal under light conditions and cannot effectively stimulate the active bacterial agent prepared in the comparative example. The number of receptors on the membrane of microorganisms is reduced in the sewage system containing high concentrations of halogen organic matter, and they cannot receive external electrical signal stimulation. The resulting bacterial flocs are small and compact, contain more inorganic matter, and the sludge activity is poor.

[0129] Comparative Example 2: A method for treating VOCs in sewage. The specific preparation method is the same as that in Example 2, except that the unique high-quality bacterial flora of the present invention is modified, and an equal amount of Proteus is used instead of Corynebacterium glutamicum to treat VOCs in sewage. The specific operation is as follows:

[0130] (1) A mixture of 20 wt% Proteus, 15 wt% Chloroflexus, 10 wt% Acidobacterium capsule and the remainder Bacteroides thetaiotaomicron was prepared at a concentration of 4×1011 A microbial inoculum with a CFU / mL was cultured in an inorganic salt culture medium at 28°C and a pH of 7.5 for 7 h. Subsequently, 1.0 mL of a 0.05 g / L chlorobenzene aqueous solution, 1.0 mL of a 2.50 g / L resorcinol aqueous solution, and 1.0 mL of a 0.15 g / L 2,4-pentanedione aqueous solution were added dropwise to the culture medium every 4 h. Degradation screening was performed four times to cultivate a high-quality bacterial population, and multiple acclimation tests were performed to obtain a high-quality bacterial population.

[0131] (2) High-quality bacterial flora were cultured to a concentration of 5×10 11 CFU / mL and the concentration difference value is less than 5%, and microbial capsules are prepared. The specific preparation method is as follows: the mixed high-quality bacterial agent and a sodium alginate solution with a concentration of 5.05 mol / L are mixed evenly in a volume ratio of 1:2, and then calcium salt is added, and the amount of calcium salt added is 27 wt% of the sodium alginate content in the sodium alginate solution. Subsequently, it is mixed with 5 times the volume of liquid paraffin to form an oil-in-water emulsion, and a sedimentation agent is added and precipitated to obtain microbial capsules, wherein the liquid paraffin contains 1 wt% of Span 80, and the sedimentation agent is a 2.5 mol / L calcium chloride solution containing 0.9 wt% of tween-80. The sedimentation agent is slowly added dropwise until the sediment at the bottom of the solution no longer increases.

[0132] (3) 98% pure trimesic acid and 45% pure ferric chloride solution were mixed evenly in a mass ratio of 1:2.5, and 650 wt% of the mass of the mixture of trimesic acid and ferric chloride solution was added to deionized water, and the pH was adjusted to 5.5 using 1.0 mol / L sodium hydroxide solution. The mixture was stirred for 18 hours, washed and dried to obtain a prefabricated carrier. The prefabricated carrier was mixed evenly with 90% manganese citrate (wherein the concentration of silver nitrate was ≤0.02 mol / L) in a mass ratio of 1:0.45, and 300 wt% of the mass of the mixture of the prefabricated carrier and manganese citrate and 0.01 mol / L sodium chloride solution were mixed in. The mixture was stirred for 10 hours, washed and dried to obtain a carrier.

[0133] (4) The microbial capsules and the carrier were mixed evenly in a mass ratio of 3:1, and 250 wt% of the mass of the mixture of microbial capsules and the carrier was added into the mixture. The mixture was aerated for 3 h under natural light conditions to obtain an active bacterial agent.

[0134] The active bacterial agent prepared in the comparative example was used in the same manner as in Example 2 to treat industrial wastewater discharged from petroleum refining and petrochemical enterprises. The prepared active bacterial agent was added to the aeration tank at a ratio of 20 mL per cubic meter of wastewater. The industrial wastewater after wastewater treatment (aeration for 3 days) was partially tested in a natural environment using the same method as in Example 2. The characterization results are as follows:

[0135]

[0136] The above characterization results indicate that, after changing the bacterial strain, it was difficult to maintain the original strain synergy, effectively forming an internal cycle and maintaining strain activity. This resulted in a significant decrease in the actual VOC removal rate. The decreases in suspended solids concentration, VSS, and SVI were even more pronounced, indicating a significant decrease in the active bacterial agent's ability to capture pollutants and a significant weakening of its VOC removal effectiveness in industrial wastewater. Furthermore, the active bacteria in the return sludge were significantly reduced, reaching a reduction of approximately 73% compared to Example 2. Consequently, it was difficult to maintain treatment activity and was no longer valuable for recycling.

[0137] Comparative Example 3: A method for treating VOCs in sewage. The specific preparation method is the same as that in Example 2, except that the unique high-quality bacterial flora of the present invention is modified, and an equal amount of Firmicutes is used to replace the Acidobacterium capsule to treat VOCs in sewage. The specific operation is as follows:

[0138] (1) A mixture of 20 wt% of Corynebacterium glutamicum, 15 wt% of Chloroflexus, 10 wt% of Firmicutes and the remainder of Bacteroides thetaiotaomicron was prepared at a concentration of 4×10 11 A microbial inoculum with a CFU / mL was cultured in an inorganic salt culture medium at 28°C and a pH of 7.5 for 7 h. Subsequently, 1.0 mL of a 0.05 g / L chlorobenzene aqueous solution, 1.0 mL of a 2.50 g / L resorcinol aqueous solution, and 1.0 mL of a 0.15 g / L 2,4-pentanedione aqueous solution were added dropwise to the culture medium every 4 h. Degradation screening was performed four times to cultivate a high-quality bacterial population, and multiple acclimation tests were performed to obtain a high-quality bacterial population.

[0139] (2) High-quality bacterial flora were cultured to a concentration of 5×10 11 CFU / mL and the concentration difference value is less than 5%, and microbial capsules are prepared. The specific preparation method is as follows: the mixed high-quality bacterial agent and a sodium alginate solution with a concentration of 5.05 mol / L are mixed evenly in a volume ratio of 1:2, and then calcium salt is added, and the amount of calcium salt added is 27 wt% of the sodium alginate content in the sodium alginate solution. Subsequently, it is mixed with 5 times the volume of liquid paraffin to form an oil-in-water emulsion, and a sedimentation agent is added and precipitated to obtain microbial capsules, wherein the liquid paraffin contains 1 wt% of Span 80, and the sedimentation agent is a 2.5 mol / L calcium chloride solution containing 0.9 wt% of tween-80. The sedimentation agent is slowly added dropwise until the sediment at the bottom of the solution no longer increases.

[0140] (3) 98% pure trimesic acid and 45% pure ferric chloride solution were mixed evenly in a mass ratio of 1:2.5, and 650 wt% of the mass of the mixture of trimesic acid and ferric chloride solution was added to deionized water, and the pH was adjusted to 5.5 using 1.0 mol / L sodium hydroxide solution. The mixture was stirred for 18 hours, washed and dried to obtain a prefabricated carrier. The prefabricated carrier was mixed evenly with 90% manganese citrate (wherein the concentration of silver nitrate was ≤0.02 mol / L) in a mass ratio of 1:0.45, and 300 wt% of the mass of the mixture of the prefabricated carrier and manganese citrate and 0.01 mol / L sodium chloride solution were mixed in. The mixture was stirred for 10 hours, washed and dried to obtain a carrier.

[0141] (4) The microbial capsules and the carrier were mixed evenly in a mass ratio of 3:1, and 250 wt% of the mass of the mixture of microbial capsules and the carrier was added into the mixture. The mixture was aerated for 3 h under natural light conditions to obtain an active bacterial agent.

[0142] The active bacterial agent prepared in the comparative example was used in the same manner as in Example 2 to treat industrial wastewater discharged from petroleum refining and petrochemical enterprises. The prepared active bacterial agent was added to the aeration tank at a ratio of 20 mL per cubic meter of wastewater. The industrial wastewater after wastewater treatment (aeration for 3 days) was partially tested in a natural environment using the same method as in Example 2. The characterization results are as follows:

[0143]

[0144] The characterization results of Comparative Examples 2 and 3 were compared with those of Example 2. It was found that the coordination relationship between the microbial flora used in the present invention cannot be easily changed, which will directly affect the treatment effect of sewage. After research and observation by the inventors, a series of nutrient exchanges, information signal transmission and gene metabolism regulation are carried out through a variety of extracellular products in the flora relationship. In the material cycle of biological elements and the interaction between microbial food loops, there is both mutual competition and synergy. In the technical solution of the present invention, after multiple domestication, the flora grows rapidly and competitively, and can produce antibiotics to poison other microorganisms, shorten the lag period on the microbial growth curve, and accelerate the microorganisms to enter the logarithmic growth period. On the other hand, the inventors also found that when the suspended solids concentration is lower than 2000 g / L, the active bacterial agent is prone to foaming in the aeration tank, the air supply per unit tank volume is reduced, and the aerobic metabolism of the microorganisms cannot be met, resulting in a reduction in the microbial polysaccharide content in the water system, and the inability to form a stable bacterial block, which has a good adsorption effect on inorganic particles and organic pollutants in sewage. When the suspended solids concentration is higher than 5000 g / L, the active bacterial agent is prone to foaming in the aeration tank, and the air supply per unit tank volume is reduced, which cannot meet the aerobic metabolism of the microorganisms, resulting in a reduction in the microbial polysaccharide content in the water system, and the inability to form a stable bacterial block, which has a good adsorption effect on inorganic particles and organic pollutants in sewage. When the active bacterial agent is 2.5 g / L, the activated sludge produced in the aeration tank will show different color changes. The part near the bottom will be short of oxygen due to long-term sedimentation. At this time, the microbial flora will begin to perform anaerobic respiration, producing metabolites such as organic acids, ethanol, and methane. This process cannot effectively adsorb and degrade organic pollutants in sewage, and will also change the water environment near the sludge and affect the activity of suspended bacteria, making the activated sludge black and accompanied by an unpleasant odor produced by sulfide. Although the suspended activated sludge can be exposed to sufficient oxygen for aerobic respiration, However, due to the fluctuation of pH, the metabolic activity of microbial polysaccharides is inhibited, and they cannot bind inorganic particles and organic pollutants in sewage in large quantities. The microbial flora cannot obtain sufficient nitrogen and carbon sources from the sewage system, resulting in malnutrition of the flora and appearing grayish white. In particular, in the process of recycling the return sludge and the remaining sludge in the sedimentation tank back into the aeration tank, the black activated sludge changes the pH of the water system, which shortens the stable period of the active bacteria and advances the decay period, resulting in poor sewage degradation ability in the secondary stage and shortened sludge age of the activated sludge.

[0145] Comparative Example 4: A method for treating VOCs in sewage. The specific preparation method is the same as that in Example 2, except that the preparation and use of the carrier unique to the present invention are not used. Ordinary biochar is used instead to treat VOCs in sewage. The specific operation is as follows:

[0146] (1) A mixture of 20 wt% of Corynebacterium glutamicum, 15 wt% of Chloroflexus, 10 wt% of Acidobacterium cysts and the remainder of Bacteroides thetaiotaomicron was prepared at a concentration of 4×10 11A microbial inoculum with a CFU / mL was cultured in an inorganic salt culture medium at 28°C and a pH of 7.5 for 7 h. Subsequently, 1.0 mL of a 0.05 g / L chlorobenzene aqueous solution, 1.0 mL of a 2.50 g / L resorcinol aqueous solution, and 1.0 mL of a 0.15 g / L 2,4-pentanedione aqueous solution were added dropwise to the culture medium every 4 h. Degradation screening was performed four times to cultivate a high-quality bacterial population, and multiple acclimation tests were performed to obtain a high-quality bacterial population.

[0147] (2) High-quality bacterial flora were cultured to a concentration of 5×10 11 CFU / mL and the concentration difference value is less than 5%, and microbial capsules are prepared. The specific preparation method is as follows: the mixed high-quality bacterial agent and a sodium alginate solution with a concentration of 5.05 mol / L are mixed evenly in a volume ratio of 1:2, and then calcium salt is added, and the amount of calcium salt added is 27 wt% of the sodium alginate content in the sodium alginate solution. Subsequently, it is mixed with 5 times the volume of liquid paraffin to form an oil-in-water emulsion, and a sedimentation agent is added and precipitated to obtain microbial capsules, wherein the liquid paraffin contains 1 wt% of Span 80, and the sedimentation agent is a 2.5 mol / L calcium chloride solution containing 0.9 wt% of tween-80. The sedimentation agent is slowly added dropwise until the sediment at the bottom of the solution no longer increases.

[0148] (3) The microbial capsules and biochar were mixed evenly in a mass ratio of 3:1, and deionized water (250 wt% of the mass of the microbial capsules and carrier mixture) was added. The mixture was aerated under natural light for 3 h to obtain an active bacterial agent.

[0149] The active bacterial agent prepared in the comparative example was used in the same manner as in Example 2 to treat industrial wastewater discharged from petroleum refining and petrochemical enterprises. The prepared active bacterial agent was added to the aeration tank at a ratio of 20 mL per cubic meter of wastewater. The industrial wastewater after wastewater treatment (aeration for 3 days) was partially tested in a natural environment using the same method as in Example 2. The characterization results are as follows:

[0150]

[0151] From the comparison of the above characterization results with Example 2, it was found that the suspended solids concentration, volatile suspended solids and sludge volume index in the water system formed by the active bacterial agent prepared in the comparative example were reduced to varying degrees. The sludge volume index is an important parameter for judging the activity and degradation performance of sludge, and can accurately reflect the sedimentation performance of sludge. When the sludge is 100-150, the sludge sedimentation performance is good and the activity is high. After research and observation by the inventors, the unique carrier prepared in the technical solution of the present invention can be used as a catalyst for photocatalytic reaction. It can not only form a heterojunction, but also form a micro-electric space in the interface area in contact with sewage, form an internal electric field with microorganisms, control the duration of microorganisms in the logarithmic growth period, and extend the stable range of microorganisms. At the same time, weak electrical stimulation can promote the formation of microbial biofilms and the secretion of extracellular polymers, which is conducive to the formation of suspended bacterial clusters.

[0152] Comparative Example 5: A commercially available facultative anaerobic granular sludge was subjected to the same performance characterization as in Example 2. The specific characterization results are as follows:

[0153]

[0154] Analysis of the above characterization results clearly shows that the commercially available facultative anaerobic granular sludge and the technical solution provided by the present invention can achieve the same treatment effect. However, the instructions for use of the commercially available facultative anaerobic granular sludge clearly state that the water system in sewage treatment cannot contain N, Cl, S and F elements, because such elements will inhibit the sewage treatment effect of the facultative anaerobic granular sludge. Compared with the active bacterial agent prepared by the technical solution of the present invention, the advantage of the present invention is that the microbial cultivation operation is simple, it has high metabolic activity during the sewage treatment process, and can avoid the influence of the climate environment on the survival rate of microorganisms.

Claims

1. A method for treating VOCs in sewage, characterized in that: The method comprises: using a special microbial degradation method, adding an active bacterial agent into target wastewater containing VOCs for aeration treatment for 1 to 3 days; The active bacterial agent is prepared by the following method: (1) Mixing an aromatic acid and an inorganic salt in water, adjusting the pH value to a weak acid, stirring the reaction, filtering, washing, and drying to obtain a pre-carrier, mixing the prepared pre-carrier with an organometallic compound, placing the mixture in a salt solution, stirring the reaction, filtering, washing, and drying to obtain a carrier; (2) Mixing the microbial capsules and the carrier in water, and aerating the water under light conditions to obtain an active bacterial agent; The aromatic acid in step (1) is trimesic acid; The inorganic salt in step (1) is a soluble iron halide salt; The organometallic compound in step (1) is manganese citrate; The salt solution in step (1) is a sodium chloride aqueous solution; The microbial capsules in step (2) are prepared by the following method: (a) acclimating the microbial agent multiple times in the presence of halogenated hydrocarbons, benzene series, and organic ketones to produce a high-quality bacterial population; (b) Proliferation and cultivation of high-quality bacterial flora and preparation of microbial capsules; The microbial agent in step (a) is composed of a mixture of Corynebacterium glutamicum, Bacteroides thetaiotaomicron, Chloroflexus chlororaphis and Acidobacterium capsule.

2. The method for treating VOCs in sewage according to claim 1, characterized in that: The mass ratio of the aromatic acid and the inorganic salt used in step (1) is 1:(2.3-2.7). When mixed in water, the amount of water used is 600-700 wt% of the total mass of the aromatic acid and the inorganic salt.

3. A method for treating VOCs in sewage according to claim 1 or 2, characterized in that: In the step (1), the pH value is adjusted to 5 to 6, and after the first stirring reaction for 12 to 24 hours, the pre-support is filtered, washed and dried; The mass ratio of the pre-support to the organometallic compound in step (1) is 1:(0.45-0.55); The salt solution in step (1) is a 0.01-0.03 mol / L sodium chloride aqueous solution, and its amount is 300-350 wt% of the total mass of the pre-support and the organometallic compound, and the second stirring reaction is carried out for 10-12 hours.

4. The method for treating VOCs in sewage according to claim 1, characterized in that: The mass ratio of the microbial capsule to the carrier in step (2) is (2.8-3.2):1; In step (2), the microbial capsules and the carrier are mixed in water with a total mass of 200 to 300 wt%, and aerated for 2 to 4 hours under natural light conditions.

5. The method for treating VOCs in sewage according to claim 1, characterized in that: The proportion of each component in the microbial agent in step (a) is 18-22 wt% of Corynebacterium glutamicum, 13-17 wt% of Chloroflexus, 9-11 wt% of Acidobacterium saccharum, and the balance is Bacteroides thetaiotaomicron. The concentration of the microbial agent is 3×10 11 ~5×10 11 CFU / mL.

6. The method for treating VOCs in sewage according to claim 1, characterized in that: The halogenated hydrocarbon in step (a) is a chlorobenzene aqueous solution with a concentration of 0.05 g / L; The benzene series compound in step (a) is a resorcinol aqueous solution with a concentration of 2.50 g / L; The organic ketone in step (a) is a 0.15 g / L 2,4-pentanedione aqueous solution.

7. The method for treating VOCs in sewage according to claim 6, characterized in that: The volume ratio of the halogenated hydrocarbon, benzene series and organic ketone in step (a) is 1:1:

1. During the acclimation process, the three are added dropwise every 3 to 5 hours, and the total amount added each time is 0.6 to 1.0 mL / mL of microbial agent. The multiple acclimation processes in step (a) are specifically as follows: The microbial agent is proliferated and cultivated in an inorganic salt culture medium at a temperature of 27-29°C and a pH of 7.0-8.0 for 6-8 hours. Subsequently, a chlorobenzene aqueous solution, a resorcinol aqueous solution and a 2,4-pentanedione aqueous solution are added dropwise to the culture medium every 4 hours for degradation screening. The degradation screening is performed 3-5 times to cultivate a high-quality bacterial community.

8. The method for treating VOCs in sewage according to claim 1, characterized in that: The high-quality bacterial colony in step (b) was cultivated to a concentration of 4×10 11 ~6×10 11 CFU / mL, then the inoculum containing high-quality bacterial flora and sodium alginate solution with a concentration of 5.00-5.10 mol / L were mixed evenly in a volume ratio of 1: (1.8-2.2), and calcium salt was added. The amount of calcium salt added was 25-30 wt% of the sodium alginate content in the sodium alginate solution. Then, it was mixed with 4.5-5.5 times the volume of liquid paraffin to form an oil-in-water emulsion. After adding a sedimentation agent, the sedimentation was carried out to obtain a microbial capsule; The liquid paraffin contains 0.5 to 1.5 wt% of Span 80; The precipitant is a 2-3 mol / L calcium chloride solution containing 0.8-1.0 wt% tween-80, and the precipitant is slowly added dropwise until the precipitate at the bottom of the solution no longer increases.

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