Culture method of biological filter filler strain for efficiently treating VOCs (volatile organic compounds) waste gas

Abstract

The invention discloses a culture method of a biological filter filler strain for efficiently treating VOCs waste gas, relates to the technical field of biological filter filler strain culture, and aims to solve the problem of poor VOCs waste gas data monitoring effect. By monitoring the waste gas treatment efficiency and key operation parameters, the treatment capacity and the operation state of the biological filter can be mastered in time, a four-step gradient domestication mode is adopted, the concentration and the flow of VOCs are gradually increased, microbial communities have sufficient time to adapt to environmental changes, microbial inactivation or biological membrane collapse caused by sudden changes of conditions is avoided, and the service life of the biological filter is prolonged. The temperature and the pH value are monitored and adjusted in real time, the optimal environment condition of strain growth is simulated, the requirement of large-scale culture for accurate control over environment parameters is met, the culture quality is guaranteed, and meanwhile the culture efficiency and the yield are improved.

Description

Technical Field

[0001] The invention relates to the technical field of cultivating bacterial strains for biological filter fillers, and in particular to a method for cultivating bacterial strains for biological filter fillers for efficiently treating VOCs waste gas. Background Art

[0002] Biofilter filler bacterial strain cultivation refers to the process of artificially cultivating, optimizing and maintaining the microbial strains attached to the fillers filled in the filter during the process of treating waste gas or wastewater in the biofilter.

[0003] Chinese patent publication number CN103898024B discloses a method for cultivating bacterial strains for treating volatile mixed organic waste gas from petrochemical wastewater systems. The method primarily involves bacterial sample collection, amplification and culture, bacterial acclimatization, bacterial purification, and bacterial identification. The method enables targeted and stable screening, separation, and cultivation of waste gas-treating bacterial strains. The cultivated strains exhibit significant deodorizing effects in treating large volumes of organic waste gas with complex components, with low investment costs. Although the patent addresses the bacterial strain cultivation issue, the following problems remain in actual operation:

[0004] 1. There is no targeted selection of bacterial strains, and no targeted culture monitoring based on different culture methods, resulting in poor quality of bacterial culture.

[0005] 2. There is no effective setting of VOCs waste gas and environmental parameters in the biological filter, and there is no periodic monitoring of VOCs waste gas, which leads to a decrease in waste gas treatment capacity.

[0006] 3. There is no effective monitoring of the VOCs waste gas treatment efficiency and equipment operating parameters, resulting in the inability to locate abnormalities in a timely manner when they occur. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for cultivating strains of biofilter fillers for efficiently treating VOCs waste gas. By monitoring the waste gas treatment efficiency and key operating parameters, the treatment capacity and operating status of the biofilter can be timely grasped. Appearance morphology monitoring can timely detect physical abnormalities such as filler blockage and damage. Microbial status monitoring can capture changes in bacterial activity and population structure. Treatment performance monitoring quantifies the pollutant removal effect. A four-order gradient acclimation mode is adopted to gradually increase the VOCs concentration and flow rate, so that the microbial community has sufficient time to adapt to environmental changes, avoid microbial inactivation or biofilm collapse due to sudden changes in conditions, monitor and adjust temperature and pH value in real time, simulate the optimal environmental conditions for strain growth, meet the requirements of large-scale cultivation for precise control of environmental parameters, ensure cultivation quality, and improve cultivation efficiency and yield, which can solve the problems in the existing technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A method for cultivating bacteria strains for efficiently treating VOCs waste gas in a biofilter filler, comprising:

[0010] First, strains are screened from the strain library and the selected strains are processed. The culture environment of the culture medium is prepared according to the selected strains. The selected strains are inoculated into the culture medium for expanded culture. The filler of the biofilter is pretreated. The strains in the culture medium are inoculated onto the filler of the biofilter. After the inoculation is completed, a biofilm is constructed and the waste gas is passed into the biofilter. At the same time, the waste gas is gradient acclimated. The biofilm construction process in the biofilter is monitored in real time, and the real-time monitoring data is dynamically regulated.

[0011] Preferably, strains are screened from a strain library and the selected strains are processed, including:

[0012] Use gas chromatography to analyze the VOCs waste gas components and select the corresponding bacterial species based on the analysis results;

[0013] Among them, prepare a solid culture medium with target VOCs as the only carbon source, take out candidate strains from the strain library, and use the plate streak method or dilution spread plate method to inoculate the strains onto the solid culture medium plate, and select the strains with normal colony morphology and fast growth rate on the plate as the qualified strains in the initial screening;

[0014] The qualified strains from the initial screening were inoculated into shake flasks containing liquid culture medium. The shake flasks containing liquid culture medium used the target VOCs as the main carbon source. During the culture process, samples were taken regularly and the concentration changes of the target VOCs in the shake flasks were measured by gas chromatography. The degradation rate of the strains on VOCs was calculated, and the strains with high degradation rate and fast degradation speed were selected as the target strains.

[0015] The target bacterial strain is then purified and activated, and the final selected bacterial strain is obtained after the purification and activation treatment is completed.

[0016] Preferably, the culture environment of the culture medium is prepared according to the selected bacterial species, including:

[0017] Determine the nutritional requirements of the selected strains, including metabolic types and nutrients;

[0018] Adjust the pH value of the culture medium according to the growth characteristics of the bacterial species. The pH value of bacteria is between 7.0-7.5, and the pH value of fungi is between 5.0-6.0.

[0019] Then, the culture environment temperature is set according to the growth temperature of the bacteria, and the culture environment temperature is between 25-37°C;

[0020] At the same time, for liquid culture, dissolved oxygen management is also included. Dissolved oxygen management is for shake flask culture and fermenter culture. The liquid volume for shake flask culture is ≤30% of the volume, and the shaking speed is 150-200rpm. For fermenter culture, the dissolved oxygen is controlled to ≥30% saturation through ventilation rate and stirring speed.

[0021] Finally, the preparation of the culture environment is completed.

[0022] Preferably, the selected bacterial strain is inoculated into a culture medium for expansion culture, comprising:

[0023] Sterilize the inoculation tools and culture equipment before inoculating into the culture medium;

[0024] After the sterilization process is completed, the inoculum volume is confirmed, wherein the inoculum volume is 5%-10% of the culture medium volume;

[0025] After the inoculation volume is confirmed, the culture process of the strain is managed;

[0026] Strain culture process management includes:

[0027] If shake flask culture is used, the inoculated shake flask is placed on a shaker, and the temperature, rotation speed, and culture time are set according to the growth requirements of the strain. The temperature is set between 25-37°C, the shaking speed is controlled between 150-200 rpm, and the culture time is between 18-48 hours. After the temperature, rotation speed, and culture time are set, the strain is grown in the shake flask;

[0028] If a fermenter is used for expanded culture, seal the inoculated fermenter, turn on the stirring and ventilation devices, and control the dissolved oxygen content in the fermenter to ≥30% saturation by adjusting the ventilation rate and stirring speed according to the oxygen consumption characteristics of the strain. At the same time, monitor the temperature and pH value in the fermenter in real time and adjust them if they deviate from the set values;

[0029] Finally, the expanded culture of the strain in the culture medium is completed.

[0030] Preferably, the filler of the biofilter is pretreated, comprising:

[0031] First, clean the filler. Place the biofilter filler in the cleaning tank and rinse with clean water. If it is a honeycomb or porous structure filler, use a high-pressure water gun to rinse the inside of the pores. If there is stubborn oil or other substances on the surface of the filler, use chemical cleaning methods.

[0032] After the filler is cleaned, it is subjected to a modification treatment, wherein the surface of the filler is roughened, and nutrients or adsorbents are loaded on the surface of the filler after the surface roughening treatment;

[0033] After the modification is completed, sterilization is carried out. Sterilization includes high temperature sterilization and chemical sterilization. High temperature sterilization is to place the cleaned and modified filler in a high temperature drying oven for sterilization; chemical sterilization is to immerse the cleaned and modified filler in a diluted chemical solution for 30 minutes to 1 hour for sterilization;

[0034] Finally, the sterilized filler is placed in a container containing nutrient solution for activation, and the pretreatment of the filler is completed after activation.

[0035] Preferably, the bacterial strains in the culture medium are inoculated onto the filler of the biofilter, comprising:

[0036] Inoculation of fungi includes soaking inoculation, spraying inoculation or mixed inoculation;

[0037] Among them, immersion inoculation is to immerse the pretreated filler in a container filled with bacterial suspension for 2-4 hours. After the soaking is completed, the filler is fished out and the excess bacterial suspension is drained; spray inoculation is to use a sterile spray gun to evenly spray the bacterial suspension on the filler surface. During the spraying process, the pressure and flow of the spray gun are controlled to form a fine mist of bacterial suspension; mixed inoculation is to fully mix the bacterial suspension and filler in a sterile container, and stir or shake the bacteria to evenly distribute between and on the filler particles. The mixing time is 15-30 minutes;

[0038] After the inoculation, the culture is placed in a ventilated environment with a temperature between 25-37°C for 1-3 days.

[0039] After curing, the inoculation of the fungus is completed.

[0040] Preferably, after the inoculation is completed, a biofilm is constructed, and the waste gas is passed into the biofilter, and the waste gas is subjected to gradient acclimation, including:

[0041] The inoculated filler is placed in a biofilter reactor, wherein the ambient temperature is between 25-37°C, the filler humidity is between 50-70%, and the oxygen concentration is between 15%-20%;

[0042] At the same time, the waste gas is introduced into the biofilter, wherein the waste gas concentration is 10% of the design value, the gas flow rate is controlled according to the empty bed residence time of 120 seconds, and the temperature is maintained at 30±2°C.

[0043] Preferably, after the inoculation is completed, a biofilm is constructed, and the waste gas is passed into the biofilter, and the waste gas is subjected to gradient acclimation, which also includes:

[0044] After the exhaust gas is introduced, a four-step gradient acclimatization is performed;

[0045] After the fourth-step gradient acclimation, the thickness and uniformity of the biofilm were regularly checked by microscopy. In addition, biofilm samples were collected from the surface of the filler and the microbial community structure and activity were analyzed by microscopy and molecular biology techniques.

[0046] Finally, the construction of the biofilm is completed.

[0047] Preferably, real-time monitoring of the biofilm construction process in the biofilter includes:

[0048] Real-time monitoring of the biofilm construction process includes appearance morphology monitoring, microbial status monitoring, and treatment performance monitoring;

[0049] Among them, appearance morphology monitoring involves regular visual observation of the biofilter, recording the coverage of the biofilm on the filler surface, and investigating the cause if the coverage area is found to be stagnant or even decreasing. At the same time, the color change of the biofilm is observed. If there is an abnormal color of local blackening, yellowing or whitishness, the abnormal area is marked. At the same time, an ultrasonic thickness gauge is used to select fillers at different locations in the biofilter to measure the biofilm thickness. Multiple points are measured each time and the average value is taken. A curve of the biofilm thickness change over time is drawn.

[0050] Microbial status monitoring includes microscopic examination and molecular biological testing. Microscopic examination involves scraping biofilm samples from the surface of the filler in different areas of the biofilter, making temporary slides, and observing the type, number, morphology, and activity of the microorganisms under a microscope. Molecular biological testing involves using molecular biological techniques to analyze the dynamic changes in the microbial community structure in the biofilm.

[0051] Treatment performance monitoring includes waste gas treatment efficiency testing and filter operation parameter monitoring. Waste gas treatment efficiency testing is to monitor the concentration of VOCs in the inlet and outlet gases of the biofilter in real time, and calculate the degradation rate of waste gas through online monitoring equipment or regular sampling and analysis; filter operation parameter monitoring is to continuously monitor the key operating parameters of the biofilter, including gas flow, pressure, temperature, humidity and dissolved oxygen;

[0052] The real-time monitoring of the biofilm construction process is completed based on the monitoring results of appearance morphology monitoring, microbial status monitoring and treatment performance monitoring.

[0053] Preferably, dynamic regulation of real-time monitoring data includes:

[0054] According to the monitoring results of appearance morphology monitoring, microbial status monitoring and treatment performance monitoring, the real-time monitoring data is adjusted in sequence;

[0055] Perform threshold comparison between the monitoring results in the real-time monitoring data and the monitoring data of the standard strains, wherein the monitoring data of the standard strains is retrieved from the database;

[0056] According to the threshold comparison results, the threshold types that are inconsistent with the standard strain monitoring data in the monitoring results are confirmed and adjusted according to the threshold range;

[0057] At the same time, a visual report will be generated for the threshold types and threshold ranges that are inconsistent with the standard strain monitoring data, and transmitted to the display terminal for report display.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] 1. The present invention provides a method for culturing strains for efficiently treating VOCs waste gas biofilter fillers. Solid culture medium is prepared using target VOCs as the sole carbon source. Combined with the plate streak method or the dilution spread plate method, strains that cannot adapt to the target carbon source are quickly eliminated, and only strains that can grow using the target VOCs are retained, greatly improving screening efficiency, accurately targeting strains that are highly compatible with waste gas components, and real-time monitoring and adjustment of temperature and pH values ​​to simulate the optimal environmental conditions for strain growth. This meets the requirements for precise control of environmental parameters for large-scale cultivation, ensuring cultivation quality while improving cultivation efficiency and yield.

[0060] 2. The present invention provides a method for cultivating bacteria strains for efficiently treating VOCs waste gas in biological filter fillers. The diversified inoculation methods combined with scientific maintenance can enable the bacteria strains to quickly colonize the filler surface. Compared with the single inoculation method, it can shorten the biofilm construction time and reduce the debugging cost during the filter startup phase. It adopts a four-step gradient acclimation mode to gradually increase the VOCs concentration and flow rate, so that the microbial community has sufficient time to adapt to environmental changes and avoid microbial inactivation or biofilm collapse due to sudden changes in conditions.

[0061] 3. The present invention provides a method for cultivating bacteria strains for efficiently treating VOCs waste gas in biological filter fillers. The method combines qualitative and quantitative methods to make monitoring results more accurate and convincing. Different monitoring methods are adapted to different scenarios and precision requirements. By monitoring waste gas treatment efficiency and key operating parameters, the treatment capacity and operating status of the biological filter can be timely grasped. Appearance morphology monitoring can promptly detect physical abnormalities such as filler blockage and damage. Microbial status monitoring can capture changes in bacterial activity and population structure. Treatment performance monitoring can quantify the pollutant removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a schematic diagram of the steps for cultivating bacterial strains for the biofilter filler of the present invention. DETAILED DESCRIPTION

[0063] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0064] In order to solve the problem in the existing technology that there is no targeted selection of bacterial strains and no targeted culture monitoring according to different culture methods, which leads to poor culture quality of bacterial strains, please refer to Figure 1 , this embodiment provides the following technical solutions:

[0065] A method for cultivating bacteria strains for efficiently treating VOCs waste gas in a biofilter filler, comprising:

[0066] First, strains are screened from the strain library and the selected strains are processed. The culture environment of the culture medium is prepared according to the selected strains. The selected strains are inoculated into the culture medium for expanded culture. The filler of the biofilter is pretreated. The strains in the culture medium are inoculated onto the filler of the biofilter. After the inoculation is completed, a biofilm is constructed and the waste gas is passed into the biofilter. At the same time, the waste gas is gradient acclimated. The biofilm construction process in the biofilter is monitored in real time, and the real-time monitoring data is dynamically regulated.

[0067] Specifically, strains adapted to VOCs are targeted for selection from a strain library to ensure they possess natural degradation advantages for target pollutants. Pretreatment of the strains further enhances their metabolic activity and environmental tolerance, enabling them to efficiently decompose VOCs like benzene and toluene, ensuring treatment efficiency at the source. The culture environment is tailored to the strain's characteristics, providing optimal growth conditions and accelerating its proliferation. Expanding the culture process rapidly accumulates high concentrations of strains, shortening the biofilter's startup cycle. It also ensures that a high-density microbial community quickly forms on the surface of the inoculated filler material, enhancing its sustained waste gas treatment capacity. Pretreatment of the filler material improves its pore structure and surface hydrophilicity, providing a more suitable attachment space for the strains and promoting uniform and stable biofilm growth. Efficient biofilm construction increases the contact area between the microorganisms and the waste gas, improving mass transfer efficiency and enabling rapid adsorption and degradation of VOCs within the filter. Through gradient acclimation of the waste gas, the strains gradually adapt to varying VOC loads, improving their shock resistance and preventing a decrease in treatment efficiency due to fluctuating waste gas concentrations. Real-time monitoring of the biofilm construction process and dynamic regulation of operating parameters can ensure that the system is always in the best working condition and maintain long-term stable treatment effects.

[0068] Screening strains from the strain library and processing the selected strains, including:

[0069] Use gas chromatography to analyze the VOCs waste gas components and select the corresponding bacterial species based on the analysis results;

[0070] Among them, prepare a solid culture medium with target VOCs as the only carbon source, take out candidate strains from the strain library, and use the plate streak method or dilution spread plate method to inoculate the strains onto the solid culture medium plate, and select the strains with normal colony morphology and fast growth rate on the plate as the qualified strains in the initial screening;

[0071] The qualified strains from the initial screening were inoculated into shake flasks containing liquid culture medium. The shake flasks containing liquid culture medium used the target VOCs as the main carbon source. During the culture process, samples were taken regularly and the concentration changes of the target VOCs in the shake flasks were measured by gas chromatography. The degradation rate of the strains on VOCs was calculated, and the strains with high degradation rate and fast degradation speed were selected as the target strains.

[0072] The target bacterial strain is then purified and activated, and the final selected bacterial strain is obtained after the purification and activation treatment is completed.

[0073] Specifically, we start with precise analysis of VOCs waste gas components by gas chromatography, and select corresponding bacterial strains based on the actual composition of the waste gas, avoiding blind screening and making subsequent bacterial strain screening work more targeted. Solid culture medium is prepared with target VOCs as the sole carbon source. Combined with the plate streak method or the dilution spread plate method, it is possible to quickly eliminate strains that cannot adapt to the target carbon source and retain only strains that can grow using the target VOCs, greatly improving screening efficiency and accurately locking in strains that are highly compatible with the exhaust gas composition to ensure treatment effectiveness. During the initial screening, colony morphology and growth rate are used as indicators to preliminarily exclude strains with abnormal or slow growth and ensure the basic activity of the strains. The rescreening is carried out through shake flask culture, and the changes in the target VOCs concentration are regularly measured and the degradation rate is calculated. From the quantitative data level, strains with high degradation efficiency and fast speed are screened out. The dual screening mechanism realizes a comprehensive evaluation from appearance to performance, ensuring that the final strain has excellent degradation ability to meet actual application needs. The target strain is purified and activated to remove interference from miscellaneous bacteria, restore and enhance the activity of the strain, and improve its stability and tolerance, so that the strain can continue to play a role efficiently in the actual exhaust gas treatment process, extend its service life, reduce operating costs, provide a reliable microbial resource guarantee for industrial exhaust gas treatment, and promote the stable application and development of related environmental protection technologies.

[0074] The culture environment of the culture medium is prepared according to the selected bacterial species, including:

[0075] Determine the nutritional requirements of the selected strains, including metabolic types and nutrients;

[0076] Adjust the pH value of the culture medium according to the growth characteristics of the bacterial species. The pH value of bacteria is between 7.0-7.5, and the pH value of fungi is between 5.0-6.0.

[0077] Then, the culture environment temperature is set according to the growth temperature of the bacteria, and the culture environment temperature is between 25-37°C;

[0078] At the same time, for liquid culture, dissolved oxygen management is also included. Dissolved oxygen management is for shake flask culture and fermenter culture. The liquid volume for shake flask culture is ≤30% of the volume, and the shaking speed is 150-200rpm. For fermenter culture, the dissolved oxygen is controlled to ≥30% saturation through ventilation rate and stirring speed.

[0079] Finally, the preparation of the culture environment is completed.

[0080] Specifically, taking the metabolic type of the bacterial strain and the nutrient requirements as the core starting point, by clarifying the autotrophic / heterotrophic metabolic characteristics (such as autotrophic bacteria require inorganic carbon sources, heterotrophic bacteria require organic carbon sources), accurately matching carbon and nitrogen sources, inorganic salts and other nutritional elements to avoid growth inhibition caused by excess or deficiency of nutrients. For example, for heterotrophic anaerobic bacteria such as lactic acid bacteria, efficient reproduction under suitable nutritional conditions can be achieved by optimizing the ratio of glucose to peptone and controlling the anaerobic environment. Precise control of pH and temperature forms a "basic guarantee system" for bacterial growth: the neutral environment of 7.0-7.5, which is adapted to bacteria, maintains cell membrane permeability and enzyme activity, while the acidic conditions of 5.0-6.0, which are preferred by fungi, avoid contamination by foreign bacteria. The temperature setting of 25-37°C not only covers the optimal growth range of most microorganisms, but also fits the conventional temperature control range in laboratories, reducing equipment energy consumption. Differentiated dissolved oxygen schemes are designed for shake flask and fermenter scenarios: Shake flask culture achieves gas-liquid mixing and dissolved oxygen supply under low-cost conditions through ≤30% liquid volume and 150-200rpm oscillation, making it suitable for small-batch screening in the laboratory. The fermenter controls the dissolved oxygen saturation to ≥30% by linking the ventilation rate and agitation speed. This can meet the high oxygen demand of aerobic bacteria (such as penicillin-producing bacteria) in industrial production and avoid the obstruction of secondary metabolite synthesis due to insufficient dissolved oxygen. This hierarchical management model not only lowers the operational threshold for small-scale cultivation, but also provides standardized parameters for large-scale fermentation.

[0081] The selected strains are inoculated into the culture medium for expansion culture, including:

[0082] Sterilize the inoculation tools and culture equipment before inoculating into the culture medium;

[0083] After the sterilization process is completed, the inoculum volume is confirmed, wherein the inoculum volume is 5%-10% of the culture medium volume;

[0084] After the inoculation volume is confirmed, the culture process of the strain is managed;

[0085] Strain culture process management includes:

[0086] If shake flask culture is used, the inoculated shake flask is placed on a shaker, and the temperature, rotation speed, and culture time are set according to the growth requirements of the strain. The temperature is set between 25-37°C, the shaking speed is controlled between 150-200 rpm, and the culture time is between 18-48 hours. After the temperature, rotation speed, and culture time are set, the strain is grown in the shake flask;

[0087] If a fermenter is used for expanded culture, seal the inoculated fermenter, turn on the stirring and ventilation devices, and control the dissolved oxygen content in the fermenter to ≥30% saturation by adjusting the ventilation rate and stirring speed according to the oxygen consumption characteristics of the strain. At the same time, monitor the temperature and pH value in the fermenter in real time and adjust them if they deviate from the set values;

[0088] Finally, the expanded culture of the strain in the culture medium is completed.

[0089] Specifically, the inoculation tools and culture equipment are strictly sterilized before inoculation to eliminate contamination by foreign bacteria at the source. The presence of foreign bacteria will compete with the target strain for nutrients and space, and even produce inhibitory substances, affecting the growth of the target strain, resulting in culture failure or decreased product quality. Sterilization creates a pure growth environment for the strain, ensuring the stability and reliability of the culture. The inoculation volume is strictly controlled at 5%-10% of the culture medium volume. This ratio has been scientifically verified to enable the strain to quickly adapt and reproduce in the culture medium, avoiding slow growth due to too little inoculation, and preventing premature nutrient consumption due to excessive inoculation, maintaining a good growth and metabolic state of the strain, improving culture efficiency and success rate, and formulating differentiated management strategies for shake flask culture and fermenter culture. During shake flask culture, the appropriate temperature, rotation speed and culture time are accurately set according to the growth requirements of the strain to provide the strain with a stable and suitable growth environment, which is conducive to strain growth and accumulation of metabolites. During fermentation tank cultivation, the optimal environmental conditions for bacterial growth are simulated by controlling the dissolved oxygen content, monitoring and adjusting the temperature and pH value in real time, meeting the requirements of large-scale cultivation for precise control of environmental parameters, ensuring the cultivation quality while improving the cultivation efficiency and yield.

[0090] In order to solve the problem that the existing technology does not have effective settings for VOCs waste gas and environmental parameters in the biofilter, and does not have phased monitoring of VOCs waste gas, which leads to a decrease in waste gas treatment capacity, please refer to Figure 1 , this embodiment provides the following technical solutions:

[0091] Pre-treatment of biofilter fillers, including:

[0092] First, clean the filler. Place the biofilter filler in the cleaning tank and rinse with clean water. If it is a honeycomb or porous structure filler, use a high-pressure water gun to rinse the inside of the pores. If there is stubborn oil or other substances on the surface of the filler, use chemical cleaning methods.

[0093] After the filler is cleaned, it is subjected to a modification treatment, wherein the surface of the filler is roughened, and nutrients or adsorbents are loaded on the surface of the filler after the surface roughening treatment;

[0094] After the modification is completed, sterilization is carried out. Sterilization includes high temperature sterilization and chemical sterilization. High temperature sterilization is to place the cleaned and modified filler in a high temperature drying oven for sterilization; chemical sterilization is to immerse the cleaned and modified filler in a diluted chemical solution for 30 minutes to 1 hour for sterilization;

[0095] Finally, the sterilized filler is placed in a container containing nutrient solution for activation, and the pretreatment of the filler is completed after activation.

[0096] Specifically, cleaning is taken as the primary step in pretreatment, and differentiated cleaning strategies are adopted for fillers with different structures. Ordinary fillers are rinsed with clean water, and honeycomb or porous structure fillers are rinsed with high-pressure water guns deep into the pores to thoroughly remove impurities such as dust and sand. For stubborn oil and other substances, chemical cleaning methods are used to prevent impurities from clogging the filler pores, providing a good environment for subsequent microbial attachment and growth, and ensuring the filtration efficiency and air permeability of the biofilter. The filler surface is roughened, which significantly increases the specific surface area of ​​the filler, providing more attachment sites for microorganisms, which is conducive to the formation and growth of microbial membranes. At the same time, nutrients or adsorbents are loaded on the surface. The former continuously provides nutrients for the growth and reproduction of microorganisms, and the latter can enhance the filler's adsorption capacity for pollutants, thereby improving the biofilter's treatment effect on various pollutants. The combination of high-temperature sterilization and chemical sterilization can effectively kill various harmful microorganisms, bacteria and viruses on the filler surface and in the pores. The high temperature environment of the high temperature drying oven can denature and inactivate microbial proteins, and the chemical solution can destroy the microbial cell structure through chemical reactions. This double protection prevents harmful microorganisms from interfering with the microbial community in the biofilter and maintains the stable operation of the biofilter microbial system. The sterilized filler is placed in a container containing nutrient solution for activation, allowing the filler to fully absorb the nutrients in the nutrient solution and further activate the active sites on the filler surface.

[0097] Inoculate the bacteria in the culture medium onto the filler of the biofilter, including:

[0098] Inoculation of fungi includes soaking inoculation, spraying inoculation or mixed inoculation;

[0099] Among them, immersion inoculation is to immerse the pretreated filler in a container filled with bacterial suspension for 2-4 hours. After the soaking is completed, the filler is fished out and the excess bacterial suspension is drained; spray inoculation is to use a sterile spray gun to evenly spray the bacterial suspension on the filler surface. During the spraying process, the pressure and flow of the spray gun are controlled to form a fine mist of bacterial suspension; mixed inoculation is to fully mix the bacterial suspension and filler in a sterile container, and stir or shake the bacteria to evenly distribute between and on the filler particles. The mixing time is 15-30 minutes;

[0100] After the inoculation, the culture is placed in a ventilated environment with a temperature between 25-37°C for 1-3 days.

[0101] After curing, the inoculation of the fungus is completed.

[0102] Specifically, soaking inoculation allows the bacterial suspension to penetrate into the internal pores by immersing the filler. It is suitable for fillers with high porosity (such as ceramsite and volcanic rock), which can ensure that the bacteria are deeply colonized in the filler and expand the area of ​​microbial attachment. The 2-4 hour soaking time has been optimized to ensure that the bacteria are fully adsorbed and avoid excessive water absorption of the filler that affects subsequent ventilation. Spraying inoculation uses a sterile spray gun to form a mist-like bacterial suspension, accurately controlling the pressure and flow rate so that the bacteria evenly cover the filler surface. It is especially suitable for fillers with smooth surfaces or regular shapes (such as plastic modules) to avoid local excessive concentration caused by bacterial liquid aggregation. Mixed inoculation allows the bacterial suspension to fully contact with the filler particles through stirring / oscillation, which is suitable for granular Fillers (such as activated carbon and zeolite) can ensure that the bacteria are evenly distributed in the gaps between particles and enhance the spatial distribution balance of the microbial community. The mixing time of 15-30 minutes takes into account both efficiency and energy consumption. The temperature environment is controlled at 25-37°C after inoculation, which is in line with the optimal growth temperature of most VOCs-degrading bacteria. Ventilation and maintenance can provide sufficient oxygen to promote the reproduction of aerobic bacteria. The 1-3 day maintenance cycle can allow the bacteria to initially form a biofilm on the surface of the filler and avoid long-term maintenance that may cause the bacteria to age. Diversified inoculation methods combined with scientific maintenance can enable the bacteria to quickly colonize on the surface of the filler. Compared with the single inoculation method, it can shorten the biofilm construction time and reduce the debugging cost during the filter startup phase.

[0103] After the inoculation is completed, the biofilm is constructed and the waste gas is passed into the biofilter. At the same time, the waste gas is subjected to gradient acclimation, including:

[0104] The inoculated filler is placed in a biofilter reactor, wherein the ambient temperature is between 25-37°C, the filler humidity is between 50-70%, and the oxygen concentration is between 15%-20%;

[0105] At the same time, the waste gas is introduced into the biofilter, wherein the waste gas concentration is 10% of the design value, the gas flow rate is controlled according to the empty bed residence time of 120 seconds, and the temperature is maintained at 30±2°C.

[0106] After the exhaust gas is introduced, a four-step gradient acclimation is performed. The four-step gradient acclimation table is as follows:

[0107]

[0108]

[0109] After the fourth-step gradient acclimation, the thickness and uniformity of the biofilm were regularly checked by microscopy. In addition, biofilm samples were collected from the surface of the filler and the microbial community structure and activity were analyzed by microscopy and molecular biology techniques.

[0110] Finally, the construction of the biofilm is completed.

[0111] Specifically, the environmental parameters of the biofilter reactor are precisely set, with the temperature controlled at 25-37°C, the packing humidity maintained at 50-70%, and the oxygen concentration maintained at 15%-20%. This meets the growth requirements of most microorganisms, creates a suitable living environment for the bacteria, fully stimulates their activity, ensures efficient microbial metabolism during the biofilm construction process, and improves waste gas treatment efficiency. At the same time, precise control of the temperature, concentration, and flow rate of waste gas during introduction further stabilizes the treatment conditions, laying a good foundation for subsequent acclimation. A four-step gradient acclimation model is adopted to gradually increase the VOCs concentration and flow rate, allowing the microbial community ample time to adapt to environmental changes and avoiding microbial inactivation or biofilm collapse due to sudden changes in conditions. Each stage sets clear threshold requirements for reaching the standard, ranging from degradation rate, outlet concentration, and biofilm thickness to the time it takes to reach the standard. This phased and targeted approach strengthens the microbial treatment capacity for waste gas of varying concentrations, effectively enhancing the biofilter's adaptability and tolerance to complex waste gas conditions and ensuring the stable operation of the treatment system. Regular microscopic inspections of biofilm thickness and uniformity provide an intuitive understanding of the biofilm's growth status. Microscopic examinations and molecular biology techniques are combined to analyze the structure and activity of microbial communities, providing a deep understanding of microbial composition and functional changes at a microscopic level, enabling the timely identification of potential problems and adjustments to treatment strategies. Multi-dimensional monitoring methods provide comprehensive assurance for the quality of biofilm construction and waste gas treatment effectiveness, helping to optimize operating parameters and enhance the reliability and stability of the biofilter's waste gas treatment.

[0112] In order to solve the problem that the existing technology does not effectively monitor the VOCs waste gas treatment efficiency and equipment operating parameters, resulting in the inability to locate abnormalities in a timely manner when abnormalities occur, please refer to Figure 1 , this embodiment provides the following technical solutions:

[0113] Real-time monitoring of the biofilm construction process in the biofilter, including:

[0114] Real-time monitoring of the biofilm construction process includes appearance morphology monitoring, microbial status monitoring, and treatment performance monitoring;

[0115] Among them, appearance morphology monitoring involves regular visual observation of the biofilter, recording the coverage of the biofilm on the filler surface, and investigating the cause if the coverage area is found to be stagnant or even decreasing. At the same time, the color change of the biofilm is observed. If there is an abnormal color of local blackening, yellowing or whitishness, the abnormal area is marked. At the same time, an ultrasonic thickness gauge is used to select fillers at different locations in the biofilter to measure the biofilm thickness. Multiple points are measured each time and the average value is taken. A curve of the biofilm thickness change over time is drawn.

[0116] Microbial status monitoring includes microscopic examination and molecular biological testing. Microscopic examination involves scraping biofilm samples from the surface of the filler in different areas of the biofilter, making temporary slides, and observing the type, number, morphology, and activity of the microorganisms under a microscope. Molecular biological testing involves using molecular biological techniques to analyze the dynamic changes in the microbial community structure in the biofilm.

[0117] Treatment performance monitoring includes waste gas treatment efficiency testing and filter operation parameter monitoring. Waste gas treatment efficiency testing is to monitor the concentration of VOCs in the inlet and outlet gases of the biofilter in real time, and calculate the degradation rate of waste gas through online monitoring equipment or regular sampling and analysis; filter operation parameter monitoring is to continuously monitor the key operating parameters of the biofilter, including gas flow, pressure, temperature, humidity and dissolved oxygen;

[0118] The real-time monitoring of the biofilm construction process is completed based on the monitoring results of appearance morphology monitoring, microbial status monitoring and treatment performance monitoring.

[0119] Specifically, a comprehensive monitoring system is constructed by focusing on three core dimensions: morphology, microbial status, and treatment performance. Morphology monitoring directly reflects biofilm growth, microbial status monitoring provides a deeper understanding of the microbial ecosystem, and treatment performance monitoring correlates with actual application results. These three complementary tools provide a comprehensive overview of the biofilm development process. In morphology monitoring, visual observation can quickly and qualitatively identify abnormalities in biofilm coverage and color, while an ultrasonic thickness gauge accurately and quantitatively measures thickness. In microbial status monitoring, microscopic examination enables qualitative observation of microorganisms, while molecular biology testing quantitatively analyzes community structure. This combination of qualitative and quantitative methods ensures more accurate and convincing monitoring results, with different monitoring methods tailored to specific scenarios and accuracy requirements. Visual observation and microscopic examination are simple and provide quick access to preliminary information, while ultrasonic thickness gauges, molecular biology testing, and online monitoring equipment provide highly accurate data for in-depth analysis. This flexible combination ensures efficient monitoring while accommodating complex and ever-changing monitoring tasks. By monitoring waste gas treatment efficiency and key operating parameters, the biofilter's treatment capacity and operational status can be accurately monitored. Once it is found that the treatment efficiency has decreased or the operating parameters are abnormal, combined with other monitoring results, the problem can be quickly located and the operating strategy can be adjusted to ensure the stable and efficient operation of the biofilter and reduce the risk of failure.

[0120] Dynamically control real-time monitoring data, including:

[0121] According to the monitoring results of appearance morphology monitoring, microbial status monitoring and treatment performance monitoring, the real-time monitoring data is adjusted in sequence;

[0122] Perform threshold comparison between the monitoring results in the real-time monitoring data and the monitoring data of the standard strains, wherein the monitoring data of the standard strains is retrieved from the database;

[0123] According to the threshold comparison results, the threshold types that are inconsistent with the standard strain monitoring data in the monitoring results are confirmed and adjusted according to the threshold range;

[0124] At the same time, a visual report will be generated for the threshold types and threshold ranges that are inconsistent with the standard strain monitoring data, and transmitted to the display terminal for report display.

[0125] Specifically, through three types of monitoring—appearance, microbial status, and treatment performance—the system comprehensively covers the key elements of biofilter operation. Appearance monitoring can promptly detect physical anomalies such as packing blockage and damage. Microbial status monitoring captures changes in bacterial activity and population structure. Treatment performance monitoring quantifies pollutant removal effectiveness. Multi-dimensional data complements and validates each other, avoiding the limitations of single-source monitoring and laying a solid data foundation for precise control. Real-time monitoring data is compared against thresholds of standard bacterial species in a database, using objective data as a benchmark to determine system operating status. When discrepancies are detected with standard data, the system precisely identifies the abnormal threshold type and adjusts it based on the preset threshold range. This effectively mitigates the subjectivity and errors of human judgment, ensuring that the biofilter remains within the optimal operating parameter range and steadily improving pollutant treatment efficiency. Inconsistent threshold types and ranges are generated and transmitted to the display terminal, presenting complex data in intuitive forms such as charts and graphs. This significantly reduces the threshold for data analysis, enabling managers to quickly identify problems, understand system operating trends, and accelerate decision-making. At the same time, visual reports facilitate information sharing between different departments, promote collaborative management, and significantly improve the overall efficiency of operations and maintenance. From data monitoring, threshold comparison, parameter adjustment, to visual feedback, a complete closed-loop management process is formed. By continuously accumulating and analyzing historical data, not only can current operational issues be promptly resolved, but system operating patterns can also be discovered, providing a basis for subsequent optimization of control strategies and improvement of standard strain data thresholds.

[0126] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0127] While the embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions, and alterations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. A method for cultivating bacteria for efficiently treating VOCs waste gas in a biological filter filler, characterized in that: include: First, strains are screened from the strain library and the selected strains are processed. The culture environment of the culture medium is prepared according to the selected strains. The selected strains are inoculated into the culture medium for expanded culture. The filler of the biofilter is pretreated. The strains in the culture medium are inoculated onto the filler of the biofilter. After the inoculation is completed, a biofilm is constructed and the waste gas is passed into the biofilter. At the same time, the waste gas is gradient acclimated. The biofilm construction process in the biofilter is monitored in real time, and the real-time monitoring data is dynamically regulated.

2. The method for cultivating a strain of a biofilter filler for efficiently treating VOCs waste gas according to claim 1, characterized in that: Screening strains from the strain library and processing the selected strains, including: Use gas chromatography to analyze the VOCs waste gas components and select the corresponding bacterial species based on the analysis results; Among them, prepare a solid culture medium with target VOCs as the only carbon source, take out candidate strains from the strain library, and use the plate streak method or dilution spread plate method to inoculate the strains onto the solid culture medium plate, and select the strains with normal colony morphology and fast growth rate on the plate as the qualified strains in the initial screening; The qualified strains from the initial screening were inoculated into shake flasks containing liquid culture medium. The shake flasks containing liquid culture medium used the target VOCs as the main carbon source. During the culture process, samples were taken regularly and the concentration changes of the target VOCs in the shake flasks were measured by gas chromatography. The degradation rate of the strains on VOCs was calculated, and the strains with high degradation rate and fast degradation speed were selected as the target strains. The target bacterial strain is then purified and activated, and the final selected bacterial strain is obtained after the purification and activation treatment is completed.

3. The method for cultivating a strain of bacteria for efficiently treating VOCs waste gas in a biological filter filler according to claim 1, characterized in that: The culture environment of the culture medium is prepared according to the selected bacterial species, including: Determine the nutritional requirements of the selected strains, including metabolic types and nutrients; Adjust the pH value of the culture medium according to the growth characteristics of the bacterial species. The pH value of bacteria is between 7.0-7.5, and the pH value of fungi is between 5.0-6.

0. Then, the culture environment temperature is set according to the growth temperature of the bacteria, and the culture environment temperature is between 25-37°C; At the same time, for liquid culture, dissolved oxygen management is also included. Dissolved oxygen management is for shake flask culture and fermenter culture. The liquid volume for shake flask culture is ≤30% of the volume, and the shaking speed is 150-200rpm. For fermenter culture, the dissolved oxygen is controlled to ≥30% saturation through ventilation rate and stirring speed. Finally, the preparation of the culture environment is completed.

4. The method for cultivating a strain of a biofilter filler for efficiently treating VOCs waste gas according to claim 1, characterized in that: The selected strains are inoculated into the culture medium for expansion culture, including: Sterilize the inoculation tools and culture equipment before inoculating into the culture medium; After the sterilization process is completed, the inoculum volume is confirmed, wherein the inoculum volume is 5%-10% of the culture medium volume; After the inoculation volume is confirmed, the culture process of the strain is managed; Strain culture process management includes: If shake flask culture is used, the inoculated shake flask is placed on a shaker, and the temperature, rotation speed, and culture time are set according to the growth requirements of the strain. The temperature is set between 25-37°C, the shaking speed is controlled between 150-200 rpm, and the culture time is between 18-48 hours. After the temperature, rotation speed, and culture time are set, the strain is grown in the shake flask; If a fermenter is used for expanded culture, seal the inoculated fermenter, turn on the stirring and ventilation devices, and control the dissolved oxygen content in the fermenter to ≥30% saturation by adjusting the ventilation rate and stirring speed according to the oxygen consumption characteristics of the strain. At the same time, monitor the temperature and pH value in the fermenter in real time and adjust them if they deviate from the set values; Finally, the expanded culture of the strain in the culture medium is completed.

5. The method for cultivating a strain of bacteria for efficiently treating VOCs waste gas in a biological filter filler according to claim 1, characterized in that: Pre-treatment of biofilter fillers, including: First, clean the filler. Place the biofilter filler in the cleaning tank and rinse with clean water. If it is a honeycomb or porous structure filler, use a high-pressure water gun to rinse the inside of the pores. If there is stubborn oil or other substances on the surface of the filler, use chemical cleaning methods. After the filler is cleaned, it is subjected to a modification treatment, wherein the surface of the filler is roughened, and nutrients or adsorbents are loaded on the surface of the filler after the surface roughening treatment; After the modification is completed, sterilization is carried out. Sterilization includes high temperature sterilization and chemical sterilization. High temperature sterilization is to place the cleaned and modified filler in a high temperature drying oven for sterilization; chemical sterilization is to immerse the cleaned and modified filler in a diluted chemical solution for 30 minutes to 1 hour for sterilization; Finally, the sterilized filler is placed in a container containing nutrient solution for activation, and the pretreatment of the filler is completed after activation.

6. The method for cultivating a strain of bacteria for efficiently treating VOCs waste gas in a biological filter filler according to claim 1, characterized in that: Inoculate the bacteria in the culture medium onto the filler of the biofilter, including: Inoculation of fungi includes soaking inoculation, spraying inoculation or mixed inoculation; Among them, immersion inoculation is to immerse the pretreated filler in a container filled with bacterial suspension for 2-4 hours. After the soaking is completed, the filler is fished out and the excess bacterial suspension is drained; spray inoculation is to use a sterile spray gun to evenly spray the bacterial suspension on the filler surface. During the spraying process, the pressure and flow of the spray gun are controlled to form a fine mist of bacterial suspension; mixed inoculation is to fully mix the bacterial suspension and filler in a sterile container, and stir or shake the bacteria to evenly distribute between and on the filler particles. The mixing time is 15-30 minutes; After the inoculation, the culture is placed in a ventilated environment with a temperature between 25-37°C for 1-3 days. After curing, the inoculation of the fungus is completed.

7. The method for cultivating a strain of bacteria for efficiently treating VOCs waste gas in a biological filter filler according to claim 1, characterized in that: After the inoculation is completed, the biofilm is constructed and the waste gas is passed into the biofilter. At the same time, the waste gas is subjected to gradient acclimation, including: The inoculated filler is placed in a biofilter reactor, wherein the ambient temperature is between 25-37°C, the filler humidity is between 50-70%, and the oxygen concentration is between 15%-20%; At the same time, the waste gas is introduced into the biofilter, wherein the waste gas concentration is 10% of the design value, the gas flow rate is controlled according to the empty bed residence time of 120 seconds, and the temperature is maintained at 30±2°C.

8. The method for cultivating a strain of bacteria for efficiently treating VOCs waste gas in a biological filter as claimed in claim 7, characterized in that: After the inoculation is completed, the biofilm is constructed and the waste gas is passed into the biofilter. At the same time, the waste gas is subjected to gradient acclimation, which also includes: After the exhaust gas is introduced, a four-step gradient acclimatization is performed; After the fourth-step gradient acclimation, the thickness and uniformity of the biofilm were regularly checked by microscopy. In addition, biofilm samples were collected from the surface of the filler and the microbial community structure and activity were analyzed by microscopy and molecular biology techniques. Finally, the construction of the biofilm is completed.

9. The method for cultivating a strain of bacteria for efficiently treating VOCs waste gas in a biological filter filler according to claim 1, characterized in that: Real-time monitoring of the biofilm construction process in the biofilter, including: Real-time monitoring of the biofilm construction process includes appearance morphology monitoring, microbial status monitoring, and treatment performance monitoring; Among them, appearance morphology monitoring involves regular visual observation of the biofilter, recording the coverage of the biofilm on the filler surface, and investigating the cause if the coverage area is found to be stagnant or even decreasing. At the same time, the color change of the biofilm is observed. If there is an abnormal color of local blackening, yellowing or whitishness, the abnormal area is marked. At the same time, an ultrasonic thickness gauge is used to select fillers at different locations in the biofilter to measure the biofilm thickness. Multiple points are measured each time and the average value is taken. A curve of the biofilm thickness change over time is drawn. Microbial status monitoring includes microscopic examination and molecular biological testing. Microscopic examination involves scraping biofilm samples from the surface of the filler in different areas of the biofilter, making temporary slides, and observing the type, number, morphology, and activity of the microorganisms under a microscope. Molecular biological testing involves using molecular biological techniques to analyze the dynamic changes in the microbial community structure in the biofilm. Treatment performance monitoring includes waste gas treatment efficiency testing and filter operation parameter monitoring. Waste gas treatment efficiency testing is to monitor the concentration of VOCs in the inlet and outlet gases of the biofilter in real time, and calculate the degradation rate of waste gas through online monitoring equipment or regular sampling and analysis; filter operation parameter monitoring is to continuously monitor the key operating parameters of the biofilter, including gas flow, pressure, temperature, humidity and dissolved oxygen; The real-time monitoring of the biofilm construction process is completed based on the monitoring results of appearance morphology monitoring, microbial status monitoring and treatment performance monitoring.

10. The method for cultivating a strain of bacteria for efficiently treating VOCs waste gas in a biological filter filler according to claim 9, characterized in that: Dynamically control real-time monitoring data, including: According to the monitoring results of appearance morphology monitoring, microbial status monitoring and treatment performance monitoring, the real-time monitoring data is adjusted in sequence; Perform threshold comparison between the monitoring results in the real-time monitoring data and the monitoring data of the standard strains, wherein the monitoring data of the standard strains is retrieved from the database; According to the threshold comparison results, the threshold types that are inconsistent with the standard strain monitoring data in the monitoring results are confirmed and adjusted according to the threshold range; At the same time, a visual report will be generated for the threshold types and threshold ranges that are inconsistent with the standard strain monitoring data, and transmitted to the display terminal for report display.

Images