A method and device for in-situ screening of microbial flora and anaerobic acid production enrichment based on selective metal ion removal

Abstract

The present invention discloses a method and device for in-situ screening of microecological flora and anaerobic acid production enrichment based on selective metal ion removal, which belongs to the field of anaerobic treatment of high-concentration organic waste. The method solves the problems of coordinating the relationship between organic waste flora and improving the efficiency of anaerobic short-chain fatty acid enrichment. By gradually removing soluble, exchangeable, and carbonate-bound Fe, Co, Ni, Mg, and Ca from organic waste through a filler loaded with a chelating group, an environment lacking polyvalent metal ions is created. The method utilizes the difference in selective dependence of acid-producing fermentation flora and methanogenic flora on metal ions to force the evolution of the microecological system, regulate the interaction between polyvalent metals and acid-producing fermentation flora and methanogenic flora, exert the flora screening effect, enrich the acid-producing fermentation flora, inhibit the methanogenic flora, and promote the acid-producing fermentation flora to become the dominant bacteria and reproduce and proliferate in large quantities, thereby improving the acid production reaction and inhibiting the methanogenic reaction, thereby achieving the efficiency improvement and lossless enrichment of anaerobic acid production from high-concentration organic waste.

Description

Technical Field

[0001] The present invention belongs to the field of anaerobic treatment of high-concentration organic waste, and specifically relates to a method and device for in-situ screening of microecological flora and anaerobic acid production enrichment based on selective metal ion removal. Background Art

[0002] Currently, organic waste comes from a wide range of sources and is produced in huge quantities. Typical organic waste includes high-concentration organic wastewater, sludge, food waste, and domestic waste. High-concentration organic wastewater is widely sourced from industrial production such as food, chemicals, and papermaking. Sludge comes from sewage treatment, and food waste comes from urban catering waste. Sludge is a major by-product of urban sewage treatment. High-concentration organic wastewater, sludge, and food waste generally contain large amounts of easily degradable organic matter, pathogenic bacteria, heavy metals, and other toxic substances, posing a serious threat to the environment and health. The organic matter rich in organic waste can be recycled as a resource product after proper resource recovery. This not only reduces waste emissions and environmental hazards, but also generates additional economic and environmental benefits during the resource recovery process.

[0003] Currently, anaerobic treatment is considered to be an effective process for resource-based treatment of organic waste, and has been widely used in the treatment of high-concentration organic wastewater, sludge, food waste, and domestic waste. Anaerobic acidogenesis is one of the main processes of anaerobic treatment, which can convert macromolecular organic matter in organic waste into short-chain fatty acids. It can not only reduce the discharge of organic waste and the hazards of organic pollutants, but also the short-chain fatty acids produced can replace commercial carbon sources for biological denitrification and phosphorus removal of sewage, and can also be used as high-quality substrates for bio-electricity generation, bio-hydrogen generation, and biosynthesis of degradable plastics. The anaerobic acidogenesis process involves three stages: hydrolysis, acidification, and methanogenesis. The hydrolysis and acidification stages can convert the organic matter of organic waste into short-chain fatty acids through biodegradation, while the methanogenesis stage consumes short-chain fatty acids to generate biogas such as methane. The above processes all rely on functional bacteria and functional biological enzymes to achieve. At present, organic waste hydrolysis technology has become increasingly sophisticated. Against this background, how to enhance acidification activity and inhibit methanogenesis activity has become the main bottleneck of anaerobic acidogenesis enrichment. The disorder of the bacterial community system limits the accumulation and enrichment of short-chain fatty acids, which is mainly reflected in: (1) The acidogenic fermentation bacterial community is affected by the competition of many other bacterial communities such as methanogenic bacteria and polyphosphate bacteria, resulting in insufficient abundance of acidogenic fermentation bacterial community, low ratio in the micro-ecosystem, limited acidogenic fermentation activity, restricting hydrolysis and acidification efficiency, and hindering the degradation of large-molecule organic matter into small-molecule short-chain fatty acids; (2) The methanogenic bacteria consume short-chain fatty acids, which is not conducive to acidogenesis enrichment, limits the accumulation of short-chain fatty acids, and makes it impossible to maximize the acidogenesis recovery efficiency.

[0004] To coordinate microbial relationships and enhance anaerobic acidification enrichment efficiency, researchers have proposed various methods for regulating microbial structure, such as adding exogenous acidogenic agents, adjusting system pH (alkaline fermentation), and adding chemical methane inhibitors (sodium 2-bromoethanesulfonate). While these methods can, to a certain extent, enrich acidogenic and fermentative microorganisms and inhibit methanogenic bacteria, thereby improving hydrolysis and acidification efficiency and inhibiting methanogenic activity, they also pose challenges such as the inability of exogenous agents to remain in the environment for a long time, the need for regular dosing, high drug consumption, harsh system pH conditions that can damage reactor equipment, and residual chemical inhibitors that can affect subsequent sludge disposal. Therefore, the development of novel methods for screening microbial communities and enhancing anaerobic acidification enrichment is urgently needed. Summary of the Invention

[0005] In response to the problems existing in current organic waste resource treatment and short-chain fatty acid recovery technologies, the present invention provides a method and device for in-situ screening of microecological flora and anaerobic acid production enrichment based on selective metal ion removal, which solves the problems of coordinating the relationship between organic waste flora and improving the efficiency of anaerobic short-chain fatty acid enrichment. By gradually removing soluble, exchangeable, and carbonate-bound Fe, Co, Ni, Mg, and Ca from organic waste through fillers loaded with chelating groups, an environment lacking polyvalent metal ions is created. The selective dependence of acid-producing and fermentative flora and methanogenic flora on metal ions is utilized to force the evolution of the microecological system, regulate the interaction between polyvalent metals and acid-producing and fermentative flora, and methanogenic flora, exert the flora screening effect, enrich the acid-producing and fermentative flora, inhibit the methanogenic flora, and promote the acid-producing and fermentative flora to become the dominant bacteria and multiply and proliferate in large quantities.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for in-situ screening of microbial communities in organic waste and anaerobic acid production enrichment based on selective metal ion removal, when the organic waste is sewage sludge, comprises the following steps:

[0008] S1, acclimating the anaerobic acidogenic inoculum sludge and the chelating agent to obtain an acclimated inoculum sludge, and then completing the startup in a closed reactor uniformly loaded with a filler loaded with a chelating group to obtain a mixed system a;

[0009] S2, continuously introduce organic waste into the closed reactor described in S1, so that the loading rate of organic waste is 1-10kg SS / m 3 / d or 5~20 kg SS / m 3 / d, the residence time of organic waste is ≥48h, and the mass ratio of organic waste to filler loaded with chelating groups is 1:1.6~1:4.8, and then the mixed system a and organic waste are stirred at 100~300 rpm. When the loading rate is 1-10 kg SS / m 3 / d at 25-37o C, when the load rate is 5~20 kg SS / m 3 / d at 45-60 o C, selectively remove exchangeable and carbonate-bound metal ions in organic waste to conduct in-situ screening of microecological flora and anaerobic short-chain fatty acid enrichment, and continuously overflow and discharge the mixed system after the reaction;

[0010] S3, treating the mixed system discharged from S2 by mechanical dehydration to remove water so that the water content is ≤80%, and the obtained dehydrated filtrate is a filtrate enriched with short-chain fatty acids.

[0011] Preferably, the chelating agent described in S1 is a compound having a cationic chelating group, and the chelating group in the filler loaded with the chelating group includes tripolyphosphate, sulfonic acid, ethylenediaminediacetate, ethylenediaminetetraacetic acid, iminodiacetic acid and ethylenediaminedisuccinate, and the density of the chelating agent corresponding to the chelating group in the closed reactor is 10-40 kg / m 3 The filler is irregular spherical chitosan particles with a particle size of 3-5 mm.

[0012] Preferably, S1 acclimates the anaerobic acidogenic inoculum sludge and the chelating agent for 8-24 hours, then the volume ratio of the acclimated inoculum sludge to the closed reactor is 1:5-1:10, stirring is maintained, and the startup time is 2-7 days to obtain a mixed system a.

[0013] Preferably, when the loading rate of the organic waste, the residence time of the organic waste and the mass ratio of the organic waste to the filler loaded with chelating groups in S2 are not within the above ranges, the density of the filler loaded with chelating groups in the closed reactor is changed, and the flow rate of the organic waste is changed at the same time, so that the above three parameters simultaneously meet the above ranges.

[0014] Preferably, the pH of S2 during anaerobic short-chain fatty acid enrichment is 6.0-8.5. During the reaction, the metal occurrence form and content in the organic waste, as well as the biogas yield, enzyme activity, short-chain fatty acid concentration and bacterial community structure are measured. 1 g of filler loaded with chelating groups is taken out every 1-3 days to detect the ion exchange capacity; wherein: the soluble multivalent metal content is reduced to <5 mg / g SS, the exchangeable multivalent metal content is reduced to <3 mg / g SS, and the carbonate-bound multivalent metal content is reduced to <0.1 mg / g SS; the acetate kinase activity is >20 U / g SS, the butyrate kinase activity is >3.5 U / g SS, the coenzyme F420 enzyme activity is <50 U / gSS, the abundance of the acid-producing fermentation bacteria community is >40%, the abundance of the methanogenic bacteria community is <25%, and the biogas yield is <1 m 3 / ton SS, short-chain fatty acid production>100 kg COD / ton SS. When the biogas production, enzyme activity, short-chain fatty acid concentration and bacterial community structure are not within the above ranges, replace the filler loaded with chelating groups, increase the density of the filler loaded with chelating groups, or reduce the loading rate of organic waste until the range is met; when the ion exchange capacity of the filler loaded with chelating groups is less than 30% of the initial ion exchange capacity, replace the filler described in S1.

[0015] Preferably, when the organic waste is high-concentration organic wastewater, when S2 continuously introduces the organic waste into the closed reactor described in S1, the domesticated inoculum sludge described in S1 is simultaneously introduced, and the volume ratio of the domesticated inoculum sludge to the organic waste is 1:4~1:9.

[0016] Preferably, when the organic waste is kitchen waste or domestic waste, the organic waste in S2 is obtained by the following process:

[0017] Dilute the initial organic waste with water to make the solid content of the diluted organic waste less than 50 kg SS / m 3 , obtaining the organic waste.

[0018] A device for in-situ screening and anaerobic acid production enrichment of microecological flora of sewage sludge or high-concentration organic wastewater based on selective metal ion removal, based on the above-mentioned method for in-situ screening and anaerobic acid production enrichment of microecological flora of organic waste based on selective metal ion removal, comprising a closed reactor with a rectangular structure, a temperature control device, an inoculated sludge acclimation tank and a mechanical dewatering machine; the closed reactor is divided into a plurality of reaction cells in the length direction, and each reaction cell is provided with two honeycomb layered filler supports spaced up and down and fitted with its own inner wall to form a spacer area, the filler support is used to support filler loaded with chelating groups, the closed reactor is provided with an inoculated sludge addition port and a first feed port for introducing sewage sludge or high-concentration organic wastewater, the first feed port and the inoculated sludge addition port are located on the same side in the length direction of the closed reactor, the first feed port is close to one end in the width direction of the closed reactor, and each A first stirring device is provided in the interval area of ​​each reaction grid, and the first feed port is connected to the outlet end of the first feed pump; the detection end of the temperature control device is provided in the reaction grid of the closed reactor, and the closed reactor is provided with a first discharge port, which is located on the other side of the length direction of the closed reactor, and an overflow channel is provided between two adjacent reaction grids. The first feed port, all overflow channels and the first discharge port are alternately distributed along one end and the other end of the width direction of the closed reactor in sequence, the inlet end of the mechanical dewatering machine is connected to the first discharge port, and the outlet end of the mechanical dewatering machine is externally connected to a filtrate barrel; a second stirring device is provided in the inoculated sludge acclimation tank, and a second feed port for adding anaerobic acid-producing inoculated sludge and chelating agent is provided at the top of the inoculated sludge acclimation tank, and a second discharge port is provided at the bottom center of the inoculated sludge acclimation tank, and the second discharge port is connected to the inoculated sludge adding port through a second feed pump.

[0019] Preferably, the closed reactor is further provided with a pH adjustment port, a vent port and a filler sampling port, and the outside of the closed reactor is provided with a metal extraction and morphology detection device, a pH online monitor, a biological enzyme activity detector, a gas collection device, a short-chain fatty acid detector, a bacterial community analyzer and an ion exchange capacity detection platform; the metal extraction and morphology detection device is used to measure the metal occurrence form and content in the organic waste, the pH online monitor is used to monitor the pH of the system in the closed reactor, the biological enzyme activity detector is used to detect the activity of acetate kinase, butyrate kinase and coenzyme F420 enzyme, the short-chain fatty acid detector and the bacterial community analyzer are used to detect the concentration of short-chain fatty acids and the bacterial community structure, respectively, and the ion exchange capacity detection platform is used to detect the ion exchange capacity of the filler loaded with chelating groups taken out from the filler sampling port. The gas collection device is used to collect the generated biogas, the outlet end of the gas collection device is connected to the inlet end of the exhaust device, and the outlet end of the exhaust device is connected to the inlet of the deodorizing filler bag, and the deodorizing filler bag is filled with activated carbon.

[0020] A device for in-situ screening and anaerobic acid production enrichment of microecological flora of food waste and domestic waste based on selective metal ion removal is disclosed. The device is based on the above-mentioned device for in-situ screening and anaerobic acid production enrichment of microecological flora of sewage sludge or high-concentration organic wastewater based on selective metal ion removal. The device also includes an organic waste pretreatment tank and a water storage tank higher than the organic waste pretreatment tank. A third stirring device is provided in the organic waste pretreatment tank. A third feed port and a water supply pipe are provided at the top of the organic waste pretreatment tank. The water storage tank is connected to the inlet of the water supply pipe. The third feed port is used for adding food waste and domestic waste. A third discharge port is provided at the bottom center of the inoculated sludge acclimation tank. The third discharge port is connected to the first feed port via a first feed pump.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] The present invention discloses an in-situ screening and anaerobic acid enrichment method for organic waste microecological flora based on selective metal ion removal. First, anaerobic acid inoculum sludge and chelating agent are subjected to acclimation treatment to remove polyvalent metal ions, thereby obtaining acclimated anaerobic acid inoculum sludge, which can quickly provide inoculum flora adapted to the polyvalent metal deficiency environment. When the organic waste is sewage sludge, 100-300 The stirring rate of rpm can ensure that the sewage sludge and the filler loaded with chelating groups are fully contacted and reacted. The filler loaded with chelating groups can gradually remove soluble, exchangeable, and carbonate-bound polyvalent metal (Fe, Co, Ni, Mg, Ca) ions from the organic waste, creating an environment lacking polyvalent metal ions. Based on the strong resistance of acid-producing fermentation bacteria and functional enzymes to the environment lacking polyvalent metal ions, and the low resistance and high sensitivity of methanogenic bacteria and functional enzymes to the environment lacking polyvalent metal ions, by controlling the loading rate, residence time and mass ratio of sewage sludge to the filler loaded with chelating groups, the polyvalent metal ions in the organic waste can be selectively removed, and a screening effect can be exerted on the two major bacteria and functional enzymes of the microecosystem, thereby changing the abundance and metabolic activity of the functional bacteria, enriching the acid-producing fermentation bacteria and functional enzymes, inhibiting the methanogenic bacteria and functional enzymes, and promoting the acid-producing fermentation bacteria to become the dominant bacteria and multiply in large quantities. The present invention promotes the hydrolysis and acidification processes, inhibits the methanogenesis process, and ultimately drives the biological metabolism of organic matter in organic waste to convert into short-chain fatty acids without adding exogenous bacterial agents and without changing the acid-base environment. It also hinders the further metabolic consumption of short-chain fatty acids, thereby breaking through the bottleneck of bacterial metabolic disorder in the acid-producing fermentation system, simultaneously improving the short-chain fatty acid yield and reducing the short-chain fatty acid consumption, and enriching short-chain fatty acids from organic waste to the greatest extent. Finally, water is removed to a water content of ≤80%. The obtained dehydrated filtrate is a filtrate enriched with short-chain fatty acids, which can be recycled as a chemical raw material, thereby improving the efficiency of organic waste resource recovery. The present invention can significantly reduce the contents of soluble metals, exchangeable metals, and carbonate-bound metals, thereby increasing the abundance of acidogenic fermentation bacteria by 1.26 to 1.28 times (>40%), reducing the abundance of methanogenic bacteria by 25.10 to 26.52% (<25%), increasing the activity of acetate kinase by 1.28 to 1.29 times (>20 U / g SS), increasing the activity of butyrate kinase by 1.27 to 1.46 times (>3.5 U / g SS), and reducing the activity of coenzyme F420 by 45.30 to 54.35% (<50 U / g SS); ultimately, the yield of short-chain fatty acids can be increased by 1.10 to 1.22 times (>100 kg COD / ton SS), and the yield of biogas can be reduced by 67.86 to 80.00% (<1 m 3 / ton SS).

[0023] The present invention simultaneously overcomes the two major bottleneck problems of low short-chain fatty acid yield caused by insufficient acid fermentation activity and consumption of short-chain fatty acids in the methane production process, and has the technical benefit of simultaneously solving the bottleneck constraint of the whole chain of microecological flora disorder. The mechanism of action of the present invention comes from the removal of metal ions in the organic waste itself, rather than the application of exogenous chemical agents or energy, and does not change the properties of the organic waste itself. The economic and environmental benefits are significant, and the efficiency of anaerobic acid production enrichment is improved above that of similar methods. The operation process of the present invention only requires stirring and temperature control, and the energy consumption is low. Microecological flora screening and enhanced anaerobic acid production enrichment can be achieved under the conditions of low drug consumption and low energy consumption, with low cost and significant economic benefits. There are no chemical residues in the organic waste, the dry matter mass of the organic waste is not increased, and the subsequent disposal and discharge of the organic waste are not affected. The present invention does not introduce excessive energy, the temperature of the reactor is mild, no toxic and harmful substances are produced during the treatment process, the anaerobic acid production reaction is not negatively affected, the reactor equipment is not damaged, and no inhibitory or environmentally polluting products are produced. This invention overcomes the challenges of conventional technologies, including the inability to retain exogenous microbial agents over a long period of time, the need for regular dosing, high drug consumption, harsh system pH conditions that damage reactor equipment, and residual chemical inhibitors that affect subsequent sludge disposal. During operation, this invention can increase packing density or reduce the organic waste loading rate (by adjusting feed flow rate, organic waste solids content, and reactor volume), improve the metal ion removal rate and its distribution, and precisely control the anaerobic acid enrichment efficiency. It offers the technical advantages of high operational precision and controllability.

[0024] Furthermore, when the organic waste is high-concentration organic wastewater, the acclimated anaerobic acid-producing inoculum sludge is added simultaneously with the introduction of the high-concentration organic wastewater. By regulating the volume ratio of the two, a sufficient amount of inoculum sludge can be maintained in the closed reactor for a long time.

[0025] Furthermore, when the organic waste is food waste or domestic waste, since the solid content of food waste and domestic waste is higher than 50 kg SS / m 3 Therefore, water must be added to dilute it first, so that the solid content of the diluted organic waste is less than 50 kg SS / m 3 , can be continuously introduced into the closed reactor and then fully contact and react with the filler loaded with chelating groups.

[0026] The present invention discloses an in-situ screening and anaerobic acid production enrichment device for microecological flora of sewage sludge or high-concentration organic wastewater based on selective metal ion removal. The stirring device in the inoculated sludge acclimation tank can acclimate the anaerobic acid production inoculated sludge and the chelating agent. Then, the acclimated inoculated sludge is transported to the closed reactor through the inoculated sludge feeding port by using the discharge port and the feed pump connected thereto. The filler support supports the filler loaded with chelating groups, and the filler loaded with chelating groups can be loaded in the closed reactor. The honeycomb layered filler support can arrange the filler loaded with chelating groups on its inner and outer surfaces. The feed port, all the overflow channels and the first discharge port are alternately distributed along one end and the other end of the width direction of the closed reactor in turn, so that the organic waste can slowly flow through the reactor in an S-shaped route, and the organic waste and the filler surface chelating group fully contact and react, the spacer formed by the filler bracket is convenient for arranging the stirring device for convenient stirring, the detection end of the temperature control device is located in the reaction grid of the closed reactor and can keep the organic waste temperature within the required range, the mechanical dehydrator can process the mixed system discharged from the discharge port for mechanical dehydration and make the moisture content meet the requirements, and the filtrate bucket can collect the filtrate enriched with short-chain fatty acids. The long-term effect of the device of the present invention is stable, simple to operate, does not require frequent dosing, and does not have complex operating equipment, can reduce the difficulty of operation and management, and has strong engineering practicality. By adjusting the metal environment conditions of the micro-ecosystem by selective metal ion removal, coordinating the relationship between the micro-ecological flora, realizing flora structure screening and flora metabolism regulation, the abundance and activity of acid-producing fermentation bacteria are insufficient, the metabolic activity of methanogens consumes short-chain fatty acids, and the restriction constraints of the micro-ecological flora system on anaerobic acid production enrichment can be solved simultaneously, and the accumulation and enrichment of short-chain fatty acids and recovery efficiency are improved.

[0027] The present invention provides an in-situ screening and anaerobic acid enrichment device for microecological flora of kitchen waste and domestic waste based on selective metal ion removal. The device has the same working process and technical effect as sewage sludge and high-concentration organic wastewater, but the difference is that the solid content of kitchen waste and domestic waste is higher than 50 kg SS / m 3 , it is necessary to add water to dilute it first, so an organic waste pretreatment pool and a water storage tank are added. The water storage tank is higher than the organic waste pretreatment pool, and water can be injected by gravity flow. Water is injected and diluted through the water pipe and the feed port. The stirring paddle can mix the food waste, domestic waste and water. Then, the diluted food waste and domestic waste are transported to the closed reactor through the feed port using the discharge port and the feed pump connected to it. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a side sectional view of the operating part of the device described in the present invention.

[0029] Figure 2 It is a side sectional view of the pre-processing part of the device of the present invention.

[0030] Figure 3 It is a front cross-sectional view of the device of the present invention.

[0031] Figure 4 It is a top plan view of the operating part of the device described in the present invention.

[0032] Figure 5 This is a top plan view of the pre-processing part of the device of the present invention

[0033] Figure 6 Schematic diagram of the filler and filler support loaded with chelating groups used in the present invention.

[0034] Figure 7 It is a schematic diagram of the flow direction of organic waste when viewed from above during the operation of the device of the present invention.

[0035] In the figure: 1-chelating agent; 2-filler loaded with chelating groups; 3-closed reactor; 4-filler support; 5-first stirring device; 6-temperature control device; 7- pH adjustment port; 8-organic waste pretreatment tank; 9-first feed port; 10-water addition pipe; 11-water storage tank; 12-first discharge port; 13-second stirring device; 14-inoculated sludge acclimation tank; 15-third stirring device; 16-second feed port; 17-second discharge port; 18-inoculated sludge addition port; 19-first feed pump; 20-third feed port; 21-second feed pump; 22-third discharge port; 23-vent port; 24-filler sampling port; 25-metal extraction and morphology detection device; 26-pH online monitor; 27-biological enzyme activity detector; 28-gas collection device; 29-short-chain fatty acid detector; 30-bacteria analyzer; 31-ion exchange capacity detection platform; 32-mechanical dehydrator; 33-supporting components; 34-deodorizing filler bag; 35-exhaust device; 36-flow channel. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0037] Anaerobic microbial ecosystems exhibit the following selective dependence on the amount and state of polyvalent metal ions: acidogenic fermentation bacteria and their functional enzymes are less dependent on polyvalent metal ions, exhibiting greater resistance in polyvalent metal-deficient environments and maintaining high hydrolysis and acidification activities. In contrast, methanogenic bacteria and their functional enzymes are more dependent on polyvalent metal ions, experiencing significant decline and methanogenesis in polyvalent metal-deficient environments. Therefore, polyvalent metal ions are an effective regulatory pathway for microbial community structure and anaerobic acid production enrichment. Removing polyvalent metal ions from anaerobic microbial ecosystems can modulate the interactions between polyvalent metal ions, microbial communities, and functional enzymes, enabling in situ screening and precise regulation of microbial communities and functional enzyme activities. Based on the above ideas, the present invention designs a method and device for in situ screening of microecological flora and anaerobic acid production enrichment based on selective metal ion removal to promote the directional evolution of flora and key enzyme activities, and drive the microecological system towards the direction of acid production accumulation and enrichment by flora screening, thereby enhancing the accumulation and enrichment efficiency of short-chain fatty acids.

[0038] In a first aspect, the present invention provides a method for in situ screening of microbial flora and anaerobic acid production enrichment based on selective metal ion removal, including the following specific embodiments:

[0039] Specific implementation method 1: It is completed according to the following steps:

[0040] (1) If Figure 6 As shown, the chelating agent 1 is loaded on the surface of the honeycomb porous structure filler by chemical grafting to form a filler 2 loaded with chelating groups, which is fixed on the filler support 4 by adhesion, and is evenly loaded in a closed reactor after dispersion; the density of the filler 2 in the closed reactor is 10-40 kg chelating agent / m 3 The chelating agent is a compound having a cationic chelating group, including tripolyphosphate, sulfonic acid, ethylenediaminediacetate, ethylenediaminetetraacetate, iminodiacetate, and ethylenediaminedisuccinate. The filler is made of chitosan particles, which are irregular spherical particles with a particle size of 3-5 mm.

[0041] (2) During the startup phase of the closed reactor, the anaerobic acidogenic inoculum sludge and the chelating agent 1 are stirred and mixed at a dry matter ratio of 2:1 to 1:5, the anaerobic acidogenic inoculum sludge is acclimated for 8-24 hours to remove polyvalent metal ions, and the acclimated anaerobic acidogenic inoculum sludge is added to the closed reactor at a volume ratio of the inoculum sludge to the effective volume of the closed reactor of 1:5 to 1:10. The stirring is maintained, and the startup time is 2-7 days, followed by the closed reactor entering a stabilization period.

[0042] (3) When the organic waste is sewage sludge, its solid content is less than 50 kg SS / m 3, organic waste is introduced into the closed reactor in the form of continuous feeding 24 hours a day. By adjusting the feed flow rate, the loading rate, residence time, and mass ratio of organic waste to chelating groups in the closed reactor are controlled, and the following requirements must be met at the same time:

[0043] a. The loading rate of organic waste in the closed reactor is 1-10 kg SS / m 3 / d;

[0044]

[0045] b. It is necessary to ensure that the residence time of organic waste in the closed reactor is not less than 2 days, that is, the volume of organic waste discharged continuously per day does not exceed 1 / 2 of the volume of the closed reactor;

[0046]

[0047] c. The dry matter ratio Q of the organic waste processed daily to the filler loaded with chelating groups is 1:1.6~1:4.8;

[0048]

[0049] If the closed reactor cannot be operated while meeting the above requirements by adjusting the feed flow rate, the packing holder 4 (loaded with the packing 2) can be added to the closed reactor, or some packing holders 4 (loaded with the packing 2) can be removed from the closed reactor to change the packing density of the reactor and the feed flow rate. The feed flow rate can be adjusted to allow the closed reactor to operate while meeting the above requirements.

[0050] (4) Adjust the temperature to 25-37 oC, the organic waste is stirred at a stirring speed of 100-300 rpm, so that the organic waste is fully contacted and reacted with the filler 2 loaded with chelating groups, and the exchangeable and carbonate-bound Fe, Co, Ni, Mg, and Ca metals in the organic waste are removed, and the occurrence state and occurrence content of the metals are selectively changed. The occurrence form and content of the metals in the organic waste are measured, and the soluble multivalent metal content is reduced to <5 mg / g SS, the exchangeable multivalent metal content is reduced to <3 mg / g SS, and the carbonate-bound multivalent metal content is reduced to <0.1 mg / g SS, thereby ensuring that the system is in a selective metal ion deficiency environment, that is, the acid-producing fermentation bacteria and functional enzyme activities are enhanced, while the methanogenic bacteria and functional enzyme activities are inhibited; at the same time, the pH is monitored, and 2 mol / L HCl or 2 mol / L NaOH solution, controlling the pH at 6.0-8.5, for anaerobic acid production and enrichment; in this process, utilizing the difference in the selective dependence of acidogenic fermentation bacteria and methanogenic bacteria on metal ions, regulating the interaction between soluble, exchangeable, and carbonate-bound metals and acidogenic fermentation bacteria, methanogenic bacteria, and biological enzymes, in situ screening and enriching acidogenic fermentation bacteria that are conducive to acid production and accumulation in the microecosystem, and inhibiting methanogenic bacteria that consume short-chain fatty acids, while changing the activity of key biological enzymes, promoting hydrolysis and acidification processes, and inhibiting methanogenesis. Without adding exogenous bacterial agents or chemical agents, in situ screening and enriching functional bacteria that are conducive to acid production and enrichment in the microecosystem, thereby improving the yield of short-chain fatty acids and non-consumption enrichment;

[0051] (5) During the operation of the closed reactor, the generated biogas is collected and the biogas production is monitored in situ. The biogas production should meet the following index range requirements, and the effect of this method is indirectly evaluated in the form of biogas inhibition; samples are taken from the closed reactor every day, and the activity of acetate kinase, butyrate kinase, and coenzyme F420 enzymes are detected using a biological enzyme activity detector. The above biological enzyme activities should meet the following index range requirements, and the bacterial screening effect of this method is indirectly evaluated by biological enzyme activity; the short-chain fatty acid concentration and bacterial community structure are detected using a short-chain fatty acid detector and a bacterial community analyzer, respectively, and the following index requirements should be met:

[0052] a. Acetate kinase activity > 20 U / g SS, butyrate kinase activity > 3.5 U / g SS, coenzyme F420 activity < 50 U / g SS;

[0053] b. The abundance of acidogenic and fermentative bacteria is >40%, and the abundance of methanogenic bacteria is <25%;

[0054] c. Biogas production <1 m 3 / ton SS, short-chain fatty acid production>100 kg COD / ton SS;

[0055] The above-mentioned detection indicators are coordinated and cooperated to realize the monitoring of the bacterial population screening and anaerobic acid production enrichment effect in the closed reactor; if the above-mentioned indicators do not meet the requirements, the filler 2 loaded with chelating groups is replaced (the chelating agent or filler therein is replaced) and replaced in the reactor, or the filler packing density is increased, or the reactor load rate is reduced until the requirements are met;

[0056] (6) discharging the organic waste from the closed reactor by continuous overflow discharge 24 hours a day and transporting it to a mechanical dehydrator by gravity discharge, with the discharge flow rate being the same as the feed flow rate;

[0057] (7) using a mechanical dehydrator and supporting components to treat the organic solid waste discharged from the closed reactor by mechanical dehydration to remove moisture to a moisture content of ≤80%, the obtained dehydrated filtrate being the filtrate, which can be recycled, and the obtained dehydrated water cake being transported for disposal;

[0058] (8) During the operation of the closed reactor 3, a small amount of filler sample is taken out every day, and the ion exchange capacity is tested using the ion exchange capacity testing platform. When the ion exchange capacity is lower than 30% of the initial ion exchange capacity, the filler needs to be replaced, and then steps (1), (3), (4), (5), (6), and (7) are repeated.

[0059] The core principle of this invention lies in the strong resistance of acidogenic fermentation bacteria and their functional enzymes to environments lacking polyvalent metal ions, resulting in enhanced activity after metal ion removal. In contrast, methanogenic bacteria and their functional enzymes are less resistant to polyvalent metal ions and their activity is suppressed after metal ion removal. By regulating the metal ion content and presence, the abundance and metabolic activity of the functional bacteria are altered, thereby promoting anaerobic acid production and inhibiting methanogenesis, ultimately significantly improving anaerobic acid production. By adjusting the reactor's packing density, chelating group type, and loading rate (achieved by adjusting feed flow rate, organic waste solids content, and reactor volume) and other operating parameters, the metal ion removal rate, amount removed, and distribution of its presence within the system can be selectively controlled. This, in turn, modulates the microbial screening process and distribution characteristics, ultimately precisely regulating anaerobic acid production efficiency. This system offers the technical advantages of high operational precision and controllability. Continuous online monitoring of various indicators during operation allows feedback adjustment of operating parameters, enabling dynamic reactor regulation and efficient, stable operation.

[0060] Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that the organic waste treated in step (3) is high-concentration organic wastewater, and anaerobic acid production inoculum sludge needs to be added simultaneously with the feeding of step (3), and the volume ratio of inoculum sludge to organic waste is 1:9~1:4, so as to maintain a sufficient amount of inoculum sludge in the closed reactor for a long time; the rest is the same as specific embodiment 1 (for other organic wastes, there is no need to continuously add inoculum sludge during the operation of the closed reactor, and the inoculum sludge amount can be maintained by relying on the self-growth of the inoculum sludge in the reactor).

[0061] Specific embodiment 3: The difference between this embodiment and specific embodiment 1 is that the organic waste processed in step (3) is kitchen waste and domestic waste. For such organic waste with a solid content higher than 50 kg SS / m 3 Organic waste must be diluted with water first, then mixed and stirred until the solid content of the organic waste is less than 50 kg SS / m 3 , and then the organic waste is introduced into the closed reactor in the form of continuous feeding for 24 hours a day; the rest is the same as the specific embodiment 1.

[0062] Specific embodiment 4: The difference between this embodiment and specific embodiment 1 or specific embodiment 2 is that step (4) is 45~60 o C, the closed reactor load rate in step (3) is 5-20 kg SS / m 3 / d; the rest is the same as the specific implementation mode 1 or the specific implementation mode 2.

[0063] Specific embodiment 5: The difference between this embodiment and specific embodiment 3 is that step (4) is 45~60 o C, the closed reactor load rate in step (3) is 5-20 kg SS / m 3 / d; the rest is the same as the specific implementation method three.

[0064] Between 45 and 60 o Under the high temperature condition of 25-37℃, the microbial metabolism regulated by metal ion removal is fast, so the reactor load rate is relatively high, which is equivalent to the second operation mode. o The medium temperature of 45~60℃ belongs to low load operation. o The high temperature of C belongs to high load operation.

[0065] In the second aspect, the present invention provides a device for in-situ screening of microbial flora and anaerobic acid production enrichment based on selective metal ion removal. Since anaerobic acid production inoculation sludge is used for both sewage sludge and high-concentration organic wastewater, this device can be used for in-situ screening of microbial flora and anaerobic acid production enrichment of sewage sludge or high-concentration organic wastewater. Figure 1and Figure 2 The side view shown (due to the long side, if Figure 1 and Figure 2 Merge, it will not be clear, so when splitting, Figure 1 The inoculated sludge injection port 18 is retained in the middle, which is easy to locate Figure 2 specific connection location) and Figure 4 and Figure 5 The top view of the combined figure shown, Figure 3 The front view shown includes an anaerobic acid production reactor module, a pretreatment module, a material feeding and discharge module, a chelating agent filler module, a dehydration module, a detection module, an odor control module, and an electronic control module.

[0066] The anaerobic acid production reactor module is the main reactor for the anaerobic acid production and enrichment reaction of organic waste, and includes a closed reactor 3, a first stirring device 5, a temperature control device 6, a pH adjustment port 7 on the closed reactor 3, and a filler sampling port 24. The closed reactor 3 is a rectangular pool body with a length: width ratio of 1:1 to 1:6 and a height of ≤2 m. It is divided into three reaction grids along the length direction. Each reaction grid is provided with two spaced filler supports above and below and in contact with the inner wall of the closed reactor 3 to form a spacer area. Each filler support is provided with a plurality of fillers (evenly distributed), and each filler is loaded with a large number of chelating agent groups. The filler support 4 is a layered honeycomb shape and plays a supporting role. The filler 2 loaded with chelating groups is located on the inner and outer surfaces of the filler support 4. An overflow channel 36 is provided between two adjacent reaction grids. The closed reactor 3 is provided with an inoculated sludge addition port 18 and a first feed port 9 and a first discharge port 12 for introducing sewage sludge or high-concentration organic wastewater. The first feed port 9 is connected to the outlet end of the first feed pump 19. The first feed port 9, all the overflow channels 36 and the first discharge port 12 are alternately distributed along one end and the other end of the width direction of the closed reactor 3. Figure 7 As shown (due to Figure 7 This is a schematic diagram of the flow direction of organic waste in the process of operation of the device of the present invention. Figure 1 and Figure 2The combined method is not easy to display intuitively, but if the feed pump and the corresponding dosing port / feed port are placed flush normally, the picture will be long and unclear, so the upper and lower placement is just for the purpose of clearly showing the schematic diagram) This allows the organic waste to flow slowly in an S-shaped route in the closed reactor 3 and fully react with the chelating groups on the filler support 4. The top of each reaction cell is designed to be a detachable top plate, which is closed during daily operation and opened when loading, unloading and replacing the closed reactor 3; the first stirring device 5 includes a first stirring paddle and a first motor. The first stirring paddle is arranged in the spacer area of ​​each reaction cell in the closed reactor 3, and one is arranged at the horizontal center of each reaction cell. , so there are a total of three first stirring devices, which are used to mix and suspend the organic waste and enhance the contact between the organic waste and the filler 2; the temperature control device 6 is an existing device, and its main components include a temperature detector, a heater, and an automatic control component. Its detection end is set on the side wall of the second compartment of the closed reactor 3, and is used to keep the temperature of the organic waste within the required range; the pH adjustment port 7 is located at the top of the second compartment of the closed reactor 3, and is used to temporarily add the above-mentioned acid solution or alkali solution to ensure that the pH of the organic waste is within the required range; the filler sampling port 24 is arranged at the top of the first compartment of the closed reactor 3, and is used to remove a small amount of filler every day for testing the ion exchange capacity.

[0067] The pretreatment module is used to adjust the solid content of organic waste and acclimate the anaerobic acid production inoculum sludge. It includes an inoculum sludge acclimatization tank 14, a second stirring device 13, a second feed port 16, and a second discharge port 17 (equipped with corresponding pipes and valves). The inoculum sludge acclimatization tank 14 is a cylindrical tank with a diameter:height ratio of 2:1 to 1:1, used to acclimate the anaerobic acid production inoculum sludge. The second stirring device 13 includes a second stirring paddle and a second motor, located at the top center of the inoculum sludge acclimatization tank 14, for mixing the anaerobic acid production inoculum sludge. The second feed port 16 is a circular port with a diameter of 20 to 50 cm, located at the top of the inoculum sludge acclimatization tank 14, for adding anaerobic acid production inoculum sludge and chelating agent. The second discharge port 17 is located at the bottom center of the inoculum sludge acclimatization tank 14, for discharging the acclimatized anaerobic acid production inoculum sludge through the second feed pump 21 and transporting it to the inoculum sludge addition port 18.

[0068] The material addition and discharge module is used for the feeding and discharging of the closed reactor 3, including the inoculated sludge addition port 18, the second feed pump 21, the first feed port 9, the first feed pump 19, the first discharge port 12, and the venting port 23 (equipped with corresponding valves). The inoculation sludge addition port 18 and the first feed port 9 are both located on the lower side of the first compartment of the closed reactor 3, and are jointly located near one end in the width direction of the closed reactor 3; the inoculation sludge addition port 18 is connected to the second feed pump 21, and is used to add the anaerobic acid production inoculation sludge discharged from the second discharge port 17 into the closed reactor 3; the first feed port 9 is connected to the first feed pump 19, and is used to add organic waste into the closed reactor 3; the first discharge port 12 is located on the upper side of the third compartment of the closed reactor 3, and the first discharge port 12 is specifically a weir-type discharge port, which is generally 10 to 30 cm away from the top of the reactor. The first discharge port 12 is connected to a discharge pipe, and the discharge pipe is equipped with a valve for discharging organic waste in the closed reactor 3; the vent 23 is arranged on the bottom side wall of each compartment of the closed reactor 3, with a total of 3, which are used for temporary discharge of organic waste during maintenance.

[0069] The chelating agent filler module is located inside the closed reactor 3, with two modules provided for each reaction cell, for a total of six modules, and is used to provide chelating agent fillers for the closed reactor 3, including fillers 2 loaded with chelating groups and filler supports 4. The filler 2 loaded with chelating groups includes a chelating agent and a filler skeleton. The chelating agent has cationic chelating groups such as tripolyphosphate, sulfonic acid, ethylenediaminediacetate, ethylenediaminetetraacetate, iminodiacetate, and ethylenediaminedisuccinate. The filler skeleton is chitosan particles in the form of irregular spherical particles with a particle size of 3-5 mm. The filler support 4 is a layered honeycomb structure made of a rectangular plastic material, which is used to provide support for the filler 2 loaded with the chelating agent. The filler 2 loaded with the chelating agent is loaded on the filler support 4 by adhesion.

[0070] The dehydration module is used to mechanically separate the solid and liquid phases of organic waste discharged from the closed reactor 3. It includes a mechanical dehydrator 32 and supporting components 33. The mechanical dehydrator 32 is one of a centrifugal dehydrator, plate and frame filter press, vacuum filter, or belt filter press, and is connected to the discharge pipe of the first discharge port 12. The supporting components 33 contain the accessories required for the operation of the mechanical dehydrator 32, including a motor, a feed pump, and a mud cake storage hopper. The outlet of the mechanical dehydrator 32 is connected to an external filtrate tank for collecting the filtrate.

[0071] The detection module, located outside the closed reactor 3 and used for online monitoring and sampling, includes a metal extraction and morphology detection device 25, an online pH monitor 26, an enzyme activity detector 27, a gas collection device 28, a short-chain fatty acid detector 29, a bacterial flora analyzer 30, and an ion exchange capacity detection platform 31. The metal extraction and morphology detection device 25 measures the metal form and content in the organic waste. The online pH monitor 26 monitors the pH of the system within the closed reactor 3. The enzyme activity detector 27 detects acetate kinase activity, butyrate kinase activity, and coenzyme F420 activity. The short-chain fatty acid detector 29 and bacterial flora analyzer 30 measure short-chain fatty acid concentration and bacterial flora structure, respectively. The ion exchange capacity detection platform 31 measures the ion exchange capacity of the chelating group-loaded filler 2 removed from the filler sampling port 24. The gas collection device 28 collects generated biogas.

[0072] The odor control module, located outside the closed reactor 3, is used to treat odors emitted during the anaerobic acidification and enrichment treatment of organic waste. It employs unpowered deodorization and includes an exhaust device 35 and a deodorizing packing 34. The outlet of the gas collection device 28 is connected to the inlet of the exhaust device 35, which is in turn connected to the inlet of the deodorizing packing 34, which is filled with activated carbon.

[0073] The stirring, valves, pumps and temperature control devices in the device of the present invention are all opened and closed by electronic control.

[0074] The present invention is a device for in-situ screening of microbial flora and anaerobic acid production enrichment based on selective metal ion removal. The specific process during operation is as follows:

[0075] (1) During the startup phase of the closed reactor 3, the anaerobic acidogenic inoculum sludge and the chelating agent 1 are first added to the inoculum sludge acclimation tank 14 from the second feed port 16, and the mixture is stirred and mixed by the second stirring device 13 to acclimate the anaerobic acidogenic inoculum sludge and remove the polyvalent metal ions. Then, the second discharge port 17 is opened, and the acclimated anaerobic acidogenic inoculum sludge is added to the closed reactor 3 from the inoculum sludge addition port 18 through the second feed pump 21. Stirring is maintained, and the closed reactor enters the stable phase after the startup time.

[0076] (2) When the organic waste is sewage sludge, its solid content is less than 50 kg SS / m 3 The organic waste is fed into the closed reactor 3 through the first feed pump 19 and the first feed port 9 in a continuous feeding manner for 24 hours a day. The loading rate, residence time, and mass ratio of the organic waste to the chelating group in the closed reactor are controlled by adjusting the feed flow rate of the first feed pump 19, while meeting the above requirements:

[0077] If the closed reactor 3 cannot be operated while meeting the above requirements by adjusting the feed flow rate, the packing holder 4 (loaded with the packing 2) can be added to the closed reactor 3, or some of the packing holders 4 (loaded with the packing 2) can be removed from the closed reactor 3 to change the packing density of the reactor. At the same time, the flow rate of the first feed pump 19 can be changed to adjust the feed flow rate so that the closed reactor can operate while meeting the above requirements.

[0078] (3) Use the temperature control device 6 to adjust the temperature to 25-37 o C., the organic waste is stirred by a first stirring device 5. During this process, the organic waste slowly flows through the closed reactor 3 in an S-shaped route, so that the organic waste is fully contacted and reacted with the filler 2 loaded with chelating groups, and the exchangeable and carbonate-bound Fe, Co, Ni, Mg, and Ca metals in the organic waste are removed, and the occurrence state and occurrence content of the metals are selectively changed. The occurrence form and content of the metals in the organic waste are measured by a metal extraction and form detection device 25. At the same time, the pH is monitored by a pH online monitor 26, and 2 mol / L HCl or 2 mol / L NaOH solution is added through the pH adjustment port 7 to control the pH to 6.0-8.5 for anaerobic acid production enrichment;

[0079] (4) During the operation of the closed reactor 3, the gas collection device 28 is used to collect the generated biogas, and the biogas production is monitored in situ. The biogas production should meet the above index range requirements; samples are taken from the closed reactor every day, and the acetate kinase activity, butyrate kinase activity, and coenzyme F420 enzyme activity are detected using a biological enzyme activity detector 27 to meet the above index range requirements; the short-chain fatty acid concentration and bacterial community structure are detected using a short-chain fatty acid detector 29 and a bacterial community analyzer 30, respectively, and the above index requirements should be met;

[0080] If the above indicators do not meet the requirements, replace the filler 2 loaded with chelating groups (replace the chelating agent or filler therein) and replace it in the reactor, or increase the filler packing density, or reduce the reactor load rate until the requirements are met;

[0081] (5) discharging the organic waste from the closed reactor through the first discharge port 12 and the discharge pipe in a continuous overflow discharge manner 24 hours a day and transporting the organic waste to the mechanical dehydrator 32 by gravity discharge, with the discharge flow rate being the same as the feed flow rate;

[0082] (6) Using a mechanical dehydrator 32 and ancillary components 33 to remove moisture to a moisture content of ≤80%, the dehydrated filtrate obtained is acid liquid, which can be collected in an acid liquid barrel for easy recycling, and the dehydrated water cake obtained is transported for disposal;

[0083] (7) During the operation of the closed reactor 3, a small amount of filler sample is taken out from the filler sampling port 24 every day, and the ion exchange capacity is detected using the ion exchange capacity detection platform 31. When the ion exchange capacity is lower than 30% of the initial ion exchange capacity, the filler needs to be replaced, and then steps (2), (3), (4), (5), and (6) are repeated.

[0084] The exhaust device 35 and the deodorizing packing bag 34 are used to control the odor, and the vent 23 is used to vent the closed reactor 3.

[0085] When the organic waste is high-concentration organic wastewater, anaerobic acid production seeding sludge is added simultaneously with the feeding in step (2) to keep a sufficient amount of seeding sludge in the closed reactor for a long time, and other conditions remain unchanged.

[0086] For the in-situ screening of microecological flora and anaerobic acid production enrichment when the organic waste is kitchen waste or domestic waste, the pretreatment module also includes an organic waste pretreatment tank 8, a third feed port 20, a water pipe 10 (equipped with a valve), a water storage tank 11, a third discharge port 22, and a third stirring device 15. The organic waste pretreatment tank 8 is a cylindrical tank body with a diameter: height ratio of 2:1 to 1:1, which is used to add water to dilute and adjust the solid content of the organic waste; the third feed port 20 is a cylindrical tank with a diameter of 20 to 50 A circular opening of 0.04 cm is arranged at the top of the organic waste pretreatment tank 8 for adding organic waste; a water adding pipe 10 is arranged at the top of the organic waste pretreatment tank 8 for injecting water from the water storage tank 11 into the organic waste pretreatment tank 8 for dilution; the height of the water storage tank 11 should be higher than the organic waste pretreatment tank 8, and water is injected by gravity flow; the third discharge port 22 is arranged at the bottom center of the organic waste pretreatment tank 8, and is connected to the first feed port 9 through the first feed pump 19, for discharging the pretreated organic waste and adding it to the closed reactor 3 through the first feed port 9; the third stirring device 15 includes a third stirring paddle and a third motor, and is arranged at the top center of the organic waste pretreatment tank 8. The third stirring paddle is located in the organic waste pretreatment tank 8 for mixing organic waste and water.

[0087] Therefore, for kitchen waste and domestic waste, the organic waste needs to be added into the organic waste pretreatment tank 8 through the third feed port 20, and then diluted with water through the water storage tank 11 and the water adding pipe 10, and mixed and stirred by the third stirring device 15 until the solid content of the organic waste is less than 50 kg SS / m 3 Then, the diluted organic waste is discharged from the third discharge port 22, and the organic waste is introduced into the closed reactor 3 through the first feed pump 19 and the first feed port 9 in a continuous feeding manner 24 hours a day, while other conditions remain unchanged.

[0088] Example 1:

[0089] Sulfonic acid groups were loaded on the surface of chitosan particles by chemical grafting to prepare fillers with an average particle size of 3.2 mm. The fillers were loaded into a closed reactor with an effective volume of 1 L and a filler density of 15 kg chelating agent / m 3 The anaerobic acid production inoculum sludge was pretreated with a sulfonic acid-loaded filler for 10 hours, with a mass ratio of 1:1. Then, 200 mL of the anaerobic acid production inoculum sludge was added to the closed reactor, with a volume ratio of 1:5 between the inoculum sludge and the closed reactor, and the startup time was 5 days. Then, high-concentration organic wastewater was continuously introduced into the closed reactor at a feed rate of 400 mL / d. The solid content of the organic wastewater was 10 kg SS / m 3 At this time, the loading rate of organic wastewater in the closed reactor is 2 kg SS / m 3 / d, the residence time is 2.5 days, and the mass ratio of organic wastewater treated daily to filler chelating groups is 1:3.75. In the above process, anaerobic acid production inoculation sludge is continuously added synchronously. o The organic wastewater was stirred at 150 rpm under 40°C conditions to ensure sufficient contact and reaction between the organic wastewater and the filler, achieving a system pH of 7.2. Simultaneously, sewage sludge was discharged continuously at a rate of 400 mL / day. During operation of the closed reactor, biogas production was monitored in situ. High-concentration organic wastewater was discharged daily from the closed reactor to measure acetate kinase, butyrate kinase, and coenzyme F420 activities. Short-chain fatty acid concentrations and bacterial flora structure were also regularly monitored. Operating parameters were adjusted based on the results of these indicators. The closed reactor system was considered stable when all of these indicators met the requirements of the present invention. Subsequently, the ion exchange capacity of the filler was tested daily. The chelating agent filler was replaced when it fell below 30% of its initial capacity.

[0090] During the stable operation period of the closed reactor using the first batch of fillers, the beneficial effects shown in Table 1 can be obtained.

[0091] Table 1 Operation results of the closed reactor of Example 1

[0092]

[0093] a The metal content is calculated as Fe, Co, Ni, Mg and Ca.

[0094] Example 2:

[0095] The tripolyphosphate was loaded on the surface of chitosan particles by chemical grafting to prepare fillers with an average particle size of 3.2 mm. The fillers were loaded into a closed reactor with an effective volume of 1 L and a filler density of 20 kg chelating agent / m3 The sludge was hydrolyzed with hydrogen peroxide, and then the anaerobic acid production seeding sludge was pretreated with a filler loaded with sulfonic acid groups for 8 hours. The mass ratio of the two was 1:1. Then, 100 mL of the anaerobic acid production seeding sludge was added to the closed reactor. The volume ratio of the seeding sludge to the closed reactor was 1:10. The startup time was 5 days. Then, the sludge was continuously introduced into the closed reactor at a feed rate of 200 mL / d. The solid content of the sludge was 25 kg SS / m 3 At this time, the sludge loading rate in the closed reactor is 5 kg SS / m 3 / d, the residence time is 5 days, and the mass ratio of the sludge treated every day to the chelating groups of the filler is 1:4. o The sludge was stirred at 250 rpm under conditions of 40 °C to ensure sufficient contact and reaction between the sludge and the filler, and the system pH was maintained at 6.9. Simultaneously, high-concentration organic wastewater was discharged continuously at a rate of 200 mL / day. During operation of the closed reactor, biogas production was monitored in situ. High-concentration organic wastewater was discharged daily from the closed reactor to measure acetate kinase, butyrate kinase, and coenzyme F420 enzyme activities. Short-chain fatty acid concentrations and bacterial flora structure were also regularly monitored. Operating parameters were adjusted based on the results of these indicators. The closed reactor system was considered stable when all of these indicators met the requirements of the present invention. Subsequently, the ion exchange capacity of the filler was tested daily. The chelating agent filler was replaced when it fell below 30% of its initial capacity.

[0096] During the stable operation period of the closed reactor using the second batch of fillers, the beneficial effects shown in Table 2 can be obtained.

[0097] Table 2 Operation results of the closed reactor of Example 2

[0098]

[0099] a The metal content is calculated as Fe, Co, Ni, Mg and Ca.

Claims

1. A method for in-situ screening of microbial flora from organic waste and anaerobic acid production enrichment based on selective metal ion removal, characterized in that: When the organic waste is sewage sludge, the following steps are involved: S1, acclimating the anaerobic acidogenic inoculum sludge and the chelating agent for 8-24 hours to obtain the acclimated inoculum sludge, and then stirring the sludge in a closed reactor uniformly loaded with a filler loaded with a chelating group to complete the startup, wherein the chelating agent is a compound having a cationic chelating group, and the chelating group in the filler loaded with the chelating group includes tripolyphosphate, sulfonic acid, ethylenediaminediacetic acid, ethylenediaminetetraacetic acid, iminodiacetic acid and ethylenediaminedisuccinate, and the density of the chelating agent corresponding to the chelating group in the closed reactor is 10-40 kg / m 3 , the filler is irregular spherical chitosan particles with a particle size of 3-5 mm, the volume ratio of the acclimated inoculum sludge to the closed reactor is 1:5-1:10, and the startup time is 2-7 days to obtain a mixed system a; S2, continuously introduce organic waste into the closed reactor described in S1, so that the loading rate of organic waste is 1-10 kgSS / m 3 / d or 5~20 kg SS / m 3 / d, the residence time of organic waste is ≥48h, and the mass ratio of organic waste to filler loaded with chelating groups is 1:1.6~1:4.8, and then the mixed system a and organic waste are stirred at 100~300 rpm. When the loading rate is 1-10 kg SS / m 3 / d at 25-37 o C, when the load rate is 5~20 kg SS / m 3 / d at 45-60 o C, selectively remove exchangeable and carbonate-bound metal ions in organic waste to conduct in-situ screening of microecological flora and anaerobic short-chain fatty acid enrichment, and continuously overflow and discharge the mixed system after the reaction; S3, treating the mixed system discharged from S2 by mechanical dehydration to remove water so that the water content is ≤80%, and the obtained dehydrated filtrate is a filtrate enriched with short-chain fatty acids.

2. The method for in-situ screening of microbial flora from organic waste and anaerobic acid production based on selective metal ion removal according to claim 1, characterized in that: When the loading rate of the organic waste, the residence time of the organic waste and the mass ratio of the organic waste to the filler loaded with chelating groups described in S2 are not within the range defined by S2, the three parameters defined by S2 are made to simultaneously meet the range by changing the density of the filler loaded with chelating groups in the closed reactor and simultaneously changing the flow rate of the organic waste.

3. The method for in-situ screening of microbial flora from organic waste and anaerobic acid production based on selective metal ion removal according to claim 1, characterized in that: The pH of S2 during anaerobic short-chain fatty acid enrichment was 6.0-8.

5. During the reaction, the metal forms and contents in the organic waste, as well as biogas production, enzyme activity, short-chain fatty acid concentration, and bacterial community structure were measured. 1 g of the filler loaded with chelating groups was removed every 1-3 days to test the ion exchange capacity. Among them: the content of soluble multivalent metals is reduced to <5 mg / g SS, the content of exchangeable multivalent metals is reduced to <3 mg / g SS, and the content of carbonate-bound multivalent metals is reduced to <0.1 mg / g SS; Acetate kinase activity >20 U / g SS, butyrate kinase activity >3.5 U / g SS, coenzyme F420 enzyme activity <50 U / g SS, acidogenic fermentation bacterial abundance >40%, methanogenic bacterial abundance <25%, biogas production <1 m 3 / ton SS, short-chain fatty acid production>100 kg COD / ton SS, when biogas production, enzyme activity, short-chain fatty acid concentration and bacterial community structure are not within the range specified by S2, replace the filler loaded with chelating groups, increase the density of the filler loaded with chelating groups or reduce the loading rate of organic waste until the above range is met; When the ion exchange capacity of the filler loaded with chelating groups is less than 30% of the initial ion exchange capacity, the filler described in S1 is replaced.

4. The method for in-situ screening of microbial flora from organic waste and anaerobic acid production based on selective metal ion removal according to claim 1, characterized in that: When the organic waste is high-concentration organic wastewater, S2 continuously introduces the organic waste into the closed reactor described in S1, and simultaneously introduces the domesticated inoculum sludge described in S1, and the volume ratio of the domesticated inoculum sludge to the organic waste is 1:4~1:

9.

5. A device for in-situ screening and anaerobic acidification enrichment of microecological flora in sewage sludge or high-concentration organic wastewater based on selective metal ion removal, characterized in that: The method for in-situ screening of microbial flora in organic waste and anaerobic acid production enrichment based on selective metal ion removal according to claim 1 comprises a closed reactor (3) with a rectangular structure, a temperature control device (6), an inoculated sludge acclimation tank (14) and a mechanical dehydrator (32); The closed reactor (3) is divided into a plurality of reaction cells in the longitudinal direction. Two honeycomb layered filler supports (4) spaced apart from each other and adhered to the inner wall of each reaction cell are arranged in each reaction cell to form a spacer area. The filler support (4) is used to support the filler (2) loaded with chelating groups. The closed reactor (3) is provided with an inoculated sludge addition port (18) and a first feed port (9) for introducing sewage sludge or high-concentration organic wastewater. The first feed port (9) and the inoculated sludge addition port (18) are located on the same side of the closed reactor (3) in the longitudinal direction. The first feed port (9) is close to one end of the closed reactor (3) in the width direction. A first stirring device (5) is provided in the spacer area of ​​each reaction cell. The first feed port (9) is connected to the outlet end of the first feed pump (19). The detection end of the temperature control device (6) is arranged in the reaction cell of the closed reactor (3), and the closed reactor (3) is provided with a first discharge port (12), which is located on the other side of the length direction of the closed reactor (3), and an overflow channel (36) is provided between two adjacent reaction cells. The first feed port (9), all overflow channels (36) and the first discharge port (12) are alternately distributed along one end and the other end of the width direction of the closed reactor (3), the inlet end of the mechanical dehydrator (32) is connected to the first discharge port (12), and the outlet end of the mechanical dehydrator (32) is externally connected to a filtrate barrel; The inoculated sludge acclimation tank (14) is provided with a second stirring device (13), the top of the inoculated sludge acclimation tank (14) is provided with a second feed port (16) for adding anaerobic acid-producing inoculated sludge and a chelating agent (1), and the bottom center of the inoculated sludge acclimation tank (14) is provided with a second discharge port (17), and the second discharge port (17) is connected to the inoculated sludge addition port (18) through a second feed pump (21).

6. The device for in-situ screening and anaerobic acidification enrichment of microecological flora in sewage sludge or high-concentration organic wastewater based on selective metal ion removal according to claim 5, characterized in that: The closed reactor (3) is further provided with a pH adjustment port (7), a venting port (23) and a filler sampling port (24); the closed reactor (3) is externally provided with a metal extraction and morphology detection device (25), a pH online monitor (26), a biological enzyme activity detector (27), a gas collection device (28), a short-chain fatty acid detector (29), a bacterial flora analyzer (30) and an ion exchange capacity detection platform (31); The metal extraction and morphology detection device (25) is used to measure the occurrence form and content of metals in organic waste, the pH online monitor (26) is used to monitor the pH of the system in the closed reactor (3), the biological enzyme activity detector (27) is used to detect the activity of acetate kinase, butyrate kinase and coenzyme F420 enzyme, the short-chain fatty acid detector (29) and the bacterial community analyzer (30) are used to detect the concentration of short-chain fatty acids and the bacterial community structure, respectively, and the ion exchange capacity detection platform (31) is used to detect the ion exchange capacity of the chelating group-loaded filler (2) taken out from the filler sampling port (24); The gas collecting device (28) is used to collect the generated biogas. The outlet end of the gas collecting device (28) is connected to the inlet end of the exhaust device (35). The outlet end of the exhaust device (35) is connected to the inlet end of the deodorizing filler bag (34). The deodorizing filler bag (34) is filled with activated carbon.

7. A device for in-situ screening and anaerobic acid production enrichment of microecological flora of kitchen waste and domestic waste based on selective metal ion removal, characterized in that: The in-situ screening and anaerobic acid production enrichment device for microbial flora of sewage sludge or high-concentration organic wastewater based on selective metal ion removal according to claim 6 further comprises an organic waste pretreatment tank (8) and a water storage tank (11) higher than the organic waste pretreatment tank (8); A third stirring device is provided in the organic waste pretreatment tank (8). A third feed port (20) and a water supply pipe (10) are provided at the top of the organic waste pretreatment tank (8). The water storage tank (11) is connected to the inlet of the water supply pipe (10). The third feed port (20) is used for adding kitchen waste and domestic waste. A third discharge port (22) is provided at the bottom center of the inoculated sludge acclimation tank (14). The third discharge port (22) is connected to the first feed port (9) via a first feed pump (19).

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