Micro-ecological flora in-situ screening and anaerobic acid production enrichment method and device based on selective metal ion removal

Abstract

The invention discloses a micro-ecological flora in-situ screening and anaerobic acid production enrichment method and device based on selective metal ion removal, belongs to the field of anaerobic treatment of high-concentration organic wastes, and solves the problems of coordinating the flora relationship of the organic wastes and improving the enrichment efficiency of anaerobic produced short-chain fatty acids. The method comprises the following steps: gradually removing soluble Fe, Co, Ni, Mg and Ca in an exchangeable state and a carbonate binding state from organic wastes by using a filler loaded with chelating groups, creating a multivalent metal ion deficiency environment, and stresses the evolution of a micro-ecosystem by using the selectivity dependence difference of acid-producing fermentation flora and methanogenic flora on metal ions, so as to achieve the purpose of improving the yield of the organic wastes. The interaction relationship between the multivalent metal and the acidogenic fermentation flora and methanogenic flora is regulated and controlled, the flora screening effect is exerted, the acidogenic fermentation flora is enriched, the methanogenic flora is inhibited, and the acidogenic fermentation flora is promoted to become dominant bacteria for mass propagation and proliferation, so that the acidogenic reaction is improved and the methanogenic reaction is inhibited; the efficiency improvement and the lossless enrichment of anaerobic acid production of the high-concentration organic waste are realized.

Description

Technical Field

[0001] The 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 has a huge output. Typical organic waste includes high-concentration organic wastewater, sludge, kitchen waste, domestic waste, etc. High-concentration organic wastewater is widely derived from industrial production such as food, chemical, and papermaking. Sludge comes from sewage treatment, and kitchen waste comes from urban catering waste. Sludge is the main by-product of urban sewage treatment. High-concentration organic wastewater, sludge, and kitchen waste generally contain a large amount 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 treatment, which can not only reduce waste emissions and environmental hazards, but also generate additional economic and environmental benefits in the resource 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, bio-hydrogen production, 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. In this context, how to improve 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 bacteria are affected by the competition of many other bacterial communities such as methanogenic bacteria and polyphosphate bacteria, resulting in insufficient abundance of acidogenic fermentation bacteria and a low ratio in the micro-ecosystem. The acidogenic fermentation activity is limited, which restricts the hydrolysis and acidification efficiency and hinders the degradation of large molecular organic matter into small molecular 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] In order to coordinate the relationship between bacterial communities and improve the efficiency of anaerobic acid production enrichment, scholars have proposed a variety of methods for regulating bacterial community structure, such as adding exogenous acid-producing bacteria, adjusting the system pH conditions (alkaline fermentation), adding chemical methanogenic inhibitors (sodium 2-bromoethane sulfonate), etc. Although these methods can enrich acid-producing fermentation bacteria and inhibit methanogenic bacteria to a certain extent, improve hydrolysis acidification efficiency and inhibit methanogenic activity, there are problems such as the inability of exogenous bacteria to be retained for a long time, the need for regular addition of bacteria, high drug consumption, harsh system pH conditions that damage reactor equipment, and residual chemical inhibitors that affect the later disposal of sludge. Therefore, it is urgent to develop new methods for screening microecological flora and enhancing anaerobic acid production enrichment. Summary of the invention

[0005] In view of the problems existing in the 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 anaerobic short-chain fatty acid enrichment efficiency. 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, and the difference in selective dependence of acidogenic fermentation flora and methanogenic flora on metal ions is utilized to force the evolution of the microecological system, regulate the interaction between polyvalent metals and acidogenic fermentation flora and methanogenic flora, give play to the flora screening effect, enrich acidogenic fermentation flora, inhibit methanogenic flora, and promote the acidogenic fermentation flora to become 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 microecological flora of 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 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 1-10kgSS / m 3 / d or 5~20kg SS / m 3 / d, the residence time of organic waste is ≥48h, and the mass ratio of organic waste to filler loaded with chelating group is 1:1.6-1:4.8, and then the mixed system a and organic waste are stirred at 100-300rpm. When the loading rate is 1-10kg SS / m 3 / d, react at 25-37℃, when the load rate is 5~20kg SS / m 3 / d at 45-60°C to selectively remove exchangeable and carbonate-bound metal ions in organic wastes, so as to carry out in-situ screening of microecological flora and anaerobic enrichment of short-chain fatty acids, 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 treats the anaerobic acidogenic inoculum sludge and the chelating agent for 8-24 hours, then the volume ratio of the domesticated inoculum sludge to the closed reactor is 1:5-1:10, stirring is maintained, and the start-up 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 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. 1g 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 <5mg / gSS, the exchangeable multivalent metal content is reduced to <3mg / gSS, and the carbonate-bound multivalent metal content is reduced to <0.1mg / gSS; the acetate kinase activity is >20U / gSS, the butyrate kinase activity is >3.5U / gSS, the coenzyme F420 enzyme activity is <50U / gSS, the acid-producing fermentation bacterial community abundance is >40%, the methanogenic bacterial community abundance is <25%, and the biogas yield is <1m 3 / ton SS, short-chain fatty acid production>100kg 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 filler density 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 lower 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 to 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 50kg SS / m 3 , obtaining the organic waste.

[0018] A device for in-situ screening and anaerobic acid enrichment of microecological flora of sewage sludge or high-concentration organic wastewater based on selective metal ion removal, based on the above-mentioned in-situ screening and anaerobic acid enrichment method 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 grids in the length direction, each reaction grid is arranged with two honeycomb layered filler supports which are spaced up and down and fit to 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 arranged 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 arranged 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 a flow channel is opened between two adjacent reaction grids, and the first feed port, all the flow 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 arranged in the inoculated sludge acclimation tank, and a second feed port for adding anaerobic acid-producing inoculated sludge and chelating agent is arranged on the top of the inoculated sludge acclimation tank, and a second discharge port is arranged at the bottom center of the inoculated sludge acclimation tank, and the second discharge port is connected to the inoculated sludge addition port through a second feed pump.

[0019] Preferably, the closed reactor is also provided with a pH adjustment port, a venting port and a filler sampling port, and 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 are provided outside the closed reactor; 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, the outlet end of the exhaust device is connected to the inlet of the deodorant filler bag, and the deodorant filler bag is filled with activated carbon.

[0020] A device for in-situ screening and anaerobic acid enrichment of microecological flora of kitchen waste and domestic waste based on selective metal ion removal, a device based on the above-mentioned method for in-situ screening and anaerobic acid 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 arranged in the organic waste pretreatment tank, a third feed port and a water adding pipe are arranged on the top of the organic waste pretreatment tank, the water storage tank is connected with the inlet of the water adding pipe, the third feed port is used for adding kitchen waste and domestic waste, a third discharge port is arranged at the bottom center of the inoculated sludge acclimation tank, and the third discharge port is connected with the first feed port through a first feed pump.

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

[0022] The invention discloses an in-situ screening and anaerobic acid enrichment method for organic waste microecological flora based on selective metal ion removal. Firstly, anaerobic acid inoculation sludge and a chelating agent are subjected to acclimation treatment to remove polyvalent metal ions, thereby obtaining acclimated anaerobic acid inoculation sludge, and quickly providing an inoculation flora adapted to a polyvalent metal-deficient environment. When the organic waste is sewage sludge, a stirring rate of 100 to 300 rpm can ensure that the sewage sludge and a filler loaded with a chelating group are fully contacted and reacted, and the filler loaded with a chelating group can gradually remove soluble, exchangeable, and carbonate-bound polyvalent metals (Fe, Co, Ni, Mg, Ca) ions, create an environment lacking polyvalent metal ions, based on the strong resistance of acidogenic fermentation bacteria and functional enzymes to the environment lacking polyvalent metal ions, 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 fillers with loaded chelating groups of sewage sludge, the polyvalent metal ions in organic wastes are selectively removed, and a screening effect is played on the two major bacteria and functional enzymes of the micro-ecosystem, the abundance and metabolic activity of functional bacteria are changed, the acidogenic fermentation bacteria and functional enzymes are enriched, the methanogenic bacteria and functional enzymes are inhibited, and the acidogenic fermentation bacteria become the dominant bacteria and multiply in large quantities. The present invention promotes the hydrolysis and acidification process, inhibits the methanogenesis process, and ultimately drives the biological metabolism of organic matter in organic waste to be converted into short-chain fatty acids without adding exogenous bacterial agents and changing the acid-base environment, and hinders the further metabolic consumption of short-chain fatty acids, thereby breaking through the bottleneck of bacterial flora metabolism disorder in the acid-producing fermentation system, and simultaneously improving the short-chain fatty acid yield and reducing the short-chain fatty acid consumption, enriching short-chain fatty acids from organic waste to the greatest extent, and finally removing water 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 recycling. The present invention can significantly reduce the content 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 (>20U / g SS), increasing the activity of butyrate kinase by 1.27 to 1.46 times (>3.5U / g SS), and reducing the activity of coenzyme F420 by 45.30 to 54.35% (<50U / g SS); ultimately, the yield of short-chain fatty acids can be increased by 1.10 to 1.22 times (>100kg COD / ton SS), and the yield of biogas can be reduced by 67.86 to 80.00% (<1m 3 / ton SS).

[0023] The present invention simultaneously overcomes the two bottleneck problems of low short-chain fatty acid yield caused by insufficient acid fermentation activity and consumption of short-chain fatty acids in the methanogenic 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 from the organic waste itself, rather than applying exogenous chemical agents or energy, and does not change the nature and conditions of the organic waste itself, with significant economic and environmental benefits, and improving the anaerobic acid production enrichment efficiency higher than the same type of method. The operation process of the present invention only requires stirring and temperature control, with low energy consumption, and can realize microecological flora screening and enhanced anaerobic acid production enrichment under the conditions of low drug consumption and low energy consumption, with low cost and significant economic benefits. There is no chemical agent residue 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, no negative impact is exerted on the anaerobic acid production reaction, no damage to the reactor equipment, and no inhibitory or environmentally polluting products are produced. The present invention can overcome the problems of traditional technologies, such as the inability to retain exogenous bacterial agents for a long time, the need to regularly add bacterial agents, high drug consumption, harsh system pH conditions that damage reactor equipment, and residual chemical inhibitors that affect the later disposal of sludge. During operation, the present invention can increase the packing density or reduce the organic waste load rate (by adjusting the feed flow rate, the solid content of the organic waste, and the reactor volume), increase the metal ion removal rate and its occurrence form distribution, and accurately control the anaerobic acid enrichment efficiency, with the technical advantages of high operation accuracy and controllability.

[0024] Furthermore, when the organic waste is high-concentration organic wastewater, the domesticated anaerobic acidogenic inoculum sludge is added simultaneously with the introduction of the high-concentration organic wastewater. By adjusting 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 kitchen waste or domestic waste, since the solid content of kitchen waste and domestic waste is higher than 50 kg SS / m 3 Therefore, water should be added to dilute it first, so that the solid content of organic waste after dilution can be less than 50kg 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 invention discloses an in-situ screening and anaerobic acid 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 acclimation sludge and the chelating agent. Then, the acclimated inoculated sludge is transported to a closed reactor through an inoculated sludge feeding port by using a discharge port and a 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 flow 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, the organic waste and the chelating group on the surface of the filler are fully contacted and reacted, and the spacer formed by the filler support is convenient for arranging the stirring device for convenient stirring. The detection end of the temperature control device is arranged in the reaction grid of the closed reactor to keep the temperature of the organic waste within the required range, and the mechanical dehydrator can process the mixed system discharged from the discharge port for mechanical dehydration and make the water content meet the requirements, and the filtrate bucket can collect the filtrate enriched with short-chain fatty acids. The device of the present invention has a long-term stable effect, simple operation, no need for frequent dosing, and no complex operating equipment, which can reduce the difficulty of operation and management, and has strong engineering practicality. The metal environment conditions of the micro-ecosystem are adjusted by selective metal ion removal, the relationship between the micro-ecological flora is coordinated, and the flora structure screening and flora metabolism regulation are realized. The abundance and activity of acid-producing fermentation bacteria are insufficient, the metabolic activity of methanogens consumes short-chain fatty acids, and the restriction of the disorder of the micro-ecological flora system on anaerobic acid enrichment can be solved simultaneously, and the short-chain fatty acid accumulation enrichment and recovery efficiency are improved.

[0027] The present invention discloses an in-situ screening and anaerobic acid enrichment device for microecological flora of kitchen waste and domestic waste based on selective metal ion removal, which is based on the same working process and technical effect as sewage sludge and high-concentration organic wastewater, except that the solid content of kitchen waste and domestic waste is higher than 50kg SS / m 3 , it is necessary to add water to dilute it first, so an organic waste pretreatment tank and a water storage tank are added. The water storage tank is higher than the organic waste pretreatment tank, and water can be injected by gravity flow. Water is injected and diluted through the water adding pipe and the feed port. The stirring paddle can mix the food waste, domestic waste and water, and 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 thereto. 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-treatment part of the device described in the present invention.

[0030] Figure 3 It is a front cross-sectional view of the device described in 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 It is a top plan view of the pre-processing part of the device of the present invention

[0033] Figure 6 It is a 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 in a top-down plane during the operation of the device of the present invention.

[0035] In the figure: 1-chelating agent; 2-filler loaded with chelating group; 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 inlet; 10-water adding 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 inlet; 17-second discharge port; 18-inoculated sludge addition port; 19-first feed inlet 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-matching 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 of the embodiments.

[0037] The anaerobic micro-ecosystem has the following characteristics of selective dependence on the amount and state of polyvalent metal ions: the acid-producing fermentation bacteria and their functional enzymes are less dependent on polyvalent metal ions, have stronger resistance in the absence of polyvalent metals, and can maintain high hydrolysis and acidification activities, while the methanogenic bacteria and their functional enzymes are more dependent on polyvalent metal ions, die in large numbers in the absence of polyvalent metals, and their methanogenic activity is significantly inhibited. Therefore, polyvalent metal ions are an effective way to regulate the microbial structure of the microbial ecosystem and the anaerobic acid enrichment efficiency. By removing polyvalent metal ions from the anaerobic micro-ecosystem, the interaction between polyvalent metal ions and the microbial community and functional enzymes can be regulated, thereby in situ screening and precise regulation of the microbial community 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, so as to promote the directional evolution of flora and key enzyme activities, drive the microecological system towards the direction of acid production accumulation and enrichment by flora screening, and enhance the accumulation and enrichment efficiency of short-chain fatty acids.

[0038] In the first aspect, the present invention provides a method for in-situ screening of microecological 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) Figure 6 As shown, the chelating agent 1 is loaded on the surface of the filler with a honeycomb porous structure 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 with 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 start-up period 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 to 24 hours to remove polyvalent metal ions, and the acclimated anaerobic acidogenic inoculum sludge is added to the closed reactor, the volume ratio of the inoculum sludge to the effective volume of the closed reactor is 1:5 to 1:10, stirring is maintained, the start-up time is 2 to 7 days, and then the closed reactor enters 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, and the loading rate, residence time, and mass ratio of organic waste to chelating group in the closed reactor are controlled by adjusting the feed flow rate, and the following requirements must be met at the same time:

[0043] a. The loading rate of organic waste in the closed reactor is 1-10kg 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 every day does not exceed 1 / 2 of the volume of the closed reactor;

[0046]

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

[0048]

[0049] If the closed reactor cannot be operated to meet the above requirements by adjusting the feed flow rate, the packing support 4 (with the packing 2) can be added to the closed reactor, or part of the packing support 4 (with the packing 2) can be removed from the closed reactor to change the packing density of the reactor and the feed flow rate, and the feed flow rate can be adjusted to make the closed reactor operate to meet the above requirements;

[0050] (4) adjusting the temperature to a medium temperature condition of 25-37° C., stirring the organic waste at a stirring speed of 100-300 rpm, so that the organic waste and the filler 2 loaded with chelating groups are fully contacted and reacted, removing the exchangeable and carbonate-bound Fe, Co, Ni, Mg, and Ca metals in the organic waste, selectively changing the occurrence state and occurrence content of the metals, measuring the occurrence form and content of the metals in the organic waste, reducing the soluble multivalent metal content to <5 mg / g SS, the exchangeable multivalent metal content to <3 mg / g SS, and the carbonate-bound multivalent metal content to <0.1 mg / g SS, so as to ensure that the system is in a selective metal ion deficiency environment, that is, to enhance the activity of acid-producing fermentation bacteria and functional enzymes, while inhibiting the activity of methanogenic bacteria and functional enzymes; at the same time, monitor the pH, and add 2 mol / L HCl or 2 mol / L NaOH solution to control the pH to 6.0-8.5 for anaerobic acid enrichment; in this process, the difference in the selective dependence of acid-producing fermentation bacteria and methanogenic bacteria on metal ions is used to regulate the interaction between soluble, exchangeable, and carbonate-bound metals and acid-producing fermentation bacteria, methanogenic bacteria, and biological enzymes, in situ screen and enrich acid-producing fermentation bacteria that are conducive to acid accumulation in the micro-ecosystem, and inhibit the methanogenic bacteria that consume short-chain fatty acids, while changing the activity of key biological enzymes, promoting hydrolysis and acidification processes, inhibiting the methanogenic process, and in situ screen and enrich functional bacteria that are conducive to acid enrichment in the micro-ecosystem without adding exogenous bacterial agents or chemical agents, 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 is detected by 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 structure are detected by 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>20U / g SS, butyrate kinase activity>3.5U / g SS, coenzyme F420 activity<50U / gSS;

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

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

[0055] The above detection indicators are coordinated to realize the monitoring of the bacterial screening and anaerobic acid production enrichment effect in the closed reactor; if the above indicators do not meet the requirements, the filler 2 loaded with chelating groups (the chelating agent or filler therein is replaced) is replaced in the reactor, or the packing density of the filler 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 conveying 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 dehydrated filtrate obtained is the filtrate, which can be recycled, and the dehydrated cement cake obtained is 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 an 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 the present invention is that the acid-producing fermentation bacteria and its functional enzymes have strong resistance to the environment lacking polyvalent metal ions, and their activity is enhanced after the removal of metal ions, while the methanogenic bacteria and their functional enzymes have weak resistance to polyvalent metal ions, and their activity is inhibited after the removal of metal ions. By adjusting the content and presence form of metal ions, the abundance and metabolic activity of the functional bacteria are changed, thereby promoting anaerobic acid production and inhibiting methanogenesis, and ultimately greatly improving anaerobic acid production enrichment. By adjusting the packing density, chelating group type, and load rate (by adjusting the feed flow rate, the solid content of organic waste, and the reactor volume) of the reactor, the metal ion removal rate, the removal amount, and the distribution of its presence form in the system can be selectively regulated, and then the screening process of the microecological flora and the distribution characteristics of the flora can be regulated, and the anaerobic acid production enrichment efficiency can be accurately regulated, which has the technical advantages of high operating accuracy and controllability. During operation, each indicator is continuously monitored online, and the operating parameters are feedback-regulated to achieve dynamic regulation of the reactor and efficient and stable operation.

[0060] Specific implementation method 2: The difference between this implementation method and specific implementation method 1 is that the organic waste treated in step (3) is high-concentration organic wastewater, and anaerobic acid-producing 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 to 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 implementation method 1 (for other organic wastes, there is no need to continuously add inoculum sludge during the operation of the closed reactor, and the amount of inoculum sludge 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 treated 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 should be diluted with water first, then mixed and stirred until the solid content of organic waste is less than 50kg 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 first specific implementation method.

[0062] Specific embodiment 4: The difference between this embodiment and specific embodiment 1 or specific embodiment 2 is that step (4) is a high temperature condition of 45 to 60°C, and the closed reactor load rate of step (3) is 5 to 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 a high temperature condition of 45 to 60°C, and the load rate of the closed reactor in step (3) is 5 to 20 kg SS / m 3 / d; the rest is the same as the specific implementation method three.

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

[0065] In the second aspect, the present invention provides a device for in-situ screening of microecological 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 microecological flora and anaerobic acid production enrichment of sewage sludge or high-concentration organic wastewater. Figure 1 and Figure 2 The side view shown in the figure (due to the long side length, if Figure 1 and Figure 2Merge, it will not be clear, so when splitting, Figure 1 The inoculated sludge injection port 18 and the fourth feed port 20 are retained, and it is easy to locate them. Figure 2 Specific connection location) and Figure 4 and Figure 5 The top view of the combined diagram 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 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 ≤2m. It is divided into three reaction grids along the length direction. Each reaction grid is provided with two spaced filler supports that are 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). Each filler is loaded with a large number of chelating agent groups. The filler support 4 is layered honeycomb-shaped 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 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 in turn. Figure 7 As shown (due to Figure 7 This is a schematic diagram of the flow direction of organic waste from a top view plane during the 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 addition 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) In this way, the organic waste can flow slowly through the closed reactor 3 in an S-shaped route and fully react with the chelating group on the filler support 4. The top of each reaction grid is designed to be a detachable top plate, which is closed during daily operation and opened when loading and 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 spacing area of ​​each reaction grid in the closed reactor 3, and one is arranged at the horizontal center of each reaction grid. , so there are a total of 3 first stirring devices, which are used to mix and suspend organic waste and enhance the contact between organic waste and 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, and its detection end is arranged on the side wall of the second compartment of the closed reactor 3, which 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 take out a small amount of filler every day for detecting the ion exchange capacity.

[0067] The pretreatment module is used to adjust the solid content of organic waste and domesticate the anaerobic acid-producing inoculum sludge, including an inoculum sludge domestication 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 domestication tank 14 is a cylindrical tank body with a diameter: height of 2:1 to 1:1, which is used to domesticate the anaerobic acid-producing inoculum sludge; the second stirring device 13 includes a second stirring paddle and a second motor, which are arranged at the top center of the inoculum sludge domestication tank 14 to mix the anaerobic acid-producing inoculum sludge; the second feed port 16 is a circular port with a diameter of 20 to 50 cm, which is arranged at the top of the inoculum sludge domestication tank 14 for adding anaerobic acid-producing inoculum sludge and chelating agent; the second discharge port 17 is arranged at the bottom center of the inoculum sludge domestication tank 14, and is used to discharge the domesticated anaerobic acid-producing inoculum sludge through the second feed pump 21 and transport it to the inoculum sludge addition port 18.

[0068] The material adding and discharging module is used for the material feeding and discharging of the closed reactor 3, including the inoculated sludge adding 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 at the lower side of the first compartment of the closed reactor 3, and are located together at one end close to 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-producing 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 venting port 23 is arranged on the bottom side wall of each compartment of the closed reactor 3, and there are 3 in total, 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 set in each reaction grid, a total of six modules, and is used to provide chelating agent fillers in the closed reactor 3, including fillers 2 loaded with chelating groups and filler brackets 4. The filler 2 loaded with chelating groups includes a chelating agent and a filler skeleton, and 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 shape of irregular spherical particles with a particle size of 3-5 mm; the filler bracket 4 is a layered honeycomb structure of a rectangular plastic material, which is used to provide support for the filler 2 loaded with the chelating agent, and the filler 2 loaded with the chelating agent is loaded on the filler bracket 4 by adhesion.

[0070] The dehydration module is used to mechanically separate the solid phase and liquid phase of the organic waste discharged from the closed reactor 3, and includes a mechanical dehydrator 32 and a matching component 33. The mechanical dehydrator 32 is one of a centrifugal dehydrator, a plate and frame filter press, a vacuum filter, and a belt filter press, and is connected to the discharge pipe on the first discharge port 12; the matching component 33 is the accessories required for the operation of the mechanical dehydrator 33, including a motor, a feed pump, and a mud cake storage bucket. The outlet end of the mechanical dehydrator 32 is connected to a filtrate bucket to collect the filtrate.

[0071] The detection module is arranged outside the closed reactor 3 for online monitoring and sampling detection, and includes 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 community analyzer 30, and an ion exchange capacity detection platform 31. The metal extraction and morphology detection device 25 is used to measure the metal occurrence form and content in the 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 filler 2 loaded with chelating groups taken out from the filler sampling port 24. The gas collection device 28 is used to collect the generated biogas.

[0072] The odor control module is arranged outside the closed reactor 3, and is used to treat the odor emitted during the anaerobic acid enrichment treatment of organic waste, and adopts unpowered deodorization, including an exhaust device 35 and a deodorizing packing bag 34. The outlet end of the gas collection device 28 is connected to the inlet end of the exhaust device 35, and the outlet end of the exhaust device 35 is connected to the inlet end of the deodorizing packing bag 34, and the deodorizing packing bag 34 is filled with activated carbon.

[0073] The opening and closing of the stirring, valve, pump and temperature control device in the device of the present invention are all controlled by electronic control.

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

[0075] (1) During the startup period of the closed reactor 3, the anaerobic acidogenic inoculum sludge and the chelating agent 1 are respectively added to the inoculum sludge acclimation tank 14 from the second feed port 16, and the inoculum sludge 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 by the second feed pump 21. Stirring is maintained, and the closed reactor enters the stable period after the startup time;

[0076] (2) 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 3 through the first feed pump 19 and the first feed port 9 in a continuous feeding manner for 24 hours a day, and the loading rate, residence time, and mass ratio of organic waste to 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 support 4 (loaded with the packing 2) may be added to the closed reactor 3, or part of the packing support 4 (loaded with the packing 2) may be removed from the closed reactor 3 to change the packing density of the reactor, and at the same time change the flow rate of the first feed pump 19 to adjust the feed flow rate so that the closed reactor can be operated while meeting the above requirements;

[0078] (3) Using a temperature control device 6 to adjust the temperature to a medium temperature condition of 25-37° C., using a first stirring device 5 to stir the organic waste, during which 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 metal extraction and form detection device 25 is used to measure the occurrence form and content of the metals in the organic waste. 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, and anaerobic acid enrichment is performed;

[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 activity of acetate kinase, butyrate kinase, and coenzyme F420 are detected by the biological enzyme activity detector 27 to meet the above index range requirements; the short-chain fatty acid concentration and the bacterial community structure are detected by the short-chain fatty acid detector 29 and the bacterial community analyzer 30 respectively, which should meet the above index requirements;

[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 packing density of the filler, 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 by continuous overflow discharge 24 hours a day and transporting it to the mechanical dehydrator 32 by gravity discharge, and the discharge flow rate is the same as the feed flow rate;

[0082] (6) using a mechanical dehydrator 32 and a matching assembly 33 to remove moisture to a moisture content of ≤80%, the dehydrated filtrate obtained is acid solution, the acid solution can be collected in an acid solution 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 2 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 port 23 is used to vent the closed reactor 3.

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

[0086] For the in-situ screening of microecological flora and anaerobic acid 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 inlet 20, a water supply 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 of 2:1 to 1:1, which is used for adding water to dilute and adjust the solid content of the organic waste; the third feed inlet 20 is a circular port with a diameter of 20 to 50 cm, which is arranged at the top of the organic waste pretreatment tank 8 for adding organic waste; the water supply pipe 10 is arranged at the organic waste pretreatment tank 8. The top of the organic waste pretreatment tank 8 is used to inject 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 gravity flow is used for water injection; 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, and is used to discharge the pretreated organic waste and add 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, which is arranged at the top center of the organic waste pretreatment tank 8, and the third stirring paddle is located in the organic waste pretreatment tank 8, and is used to mix the 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 50kg SS / m 3 Then, the third discharge port 22 discharges the diluted organic waste, 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 for 24 hours a day, while other conditions remain unchanged.

[0088] Embodiment 1:

[0089] Sulfonic acid groups were loaded on the surface of chitosan particles by chemical grafting to prepare fillers. The average particle size of the fillers was 3.2 mm. The fillers were loaded in a closed reactor with an effective volume of 1 L and a filling density of 15 kg chelating agent / m 3 The anaerobic acid production inoculum sludge was pretreated with sulfonic acid-loaded fillers for 10 hours, with a mass ratio of 1:1. Then, 200 mL of anaerobic acid production inoculum sludge was added to the closed reactor, with a volume ratio of 1:5. The start-up time was 5 days. Then, high-concentration organic wastewater was continuously introduced into the closed reactor, with a feed flow rate of 400 mL / d and a solid content of 10 kg SS / m 3 At this time, the loading rate of organic wastewater in the closed reactor is 2kg SS / m 3 / d, the residence time is 2.5 days, and the mass ratio of organic wastewater treated every day to filler chelating group is 1:3.75. In the above process, anaerobic acid production inoculation sludge is added synchronously and continuously. In the closed reactor, the organic wastewater is stirred at 35°C, and the stirring speed is 150rpm, so that the organic wastewater and the filler are fully contacted and reacted, and the system pH is 7.2. At the same time, the sewage sludge is discharged in a continuous discharging manner, and the discharge flow rate is 400mL / d. During the operation of the closed reactor, the biogas production is monitored in situ, and high-concentration organic wastewater is discharged from the closed reactor every day. The activity of acetate kinase, butyrate kinase activity, and coenzyme F420 enzyme activity are detected. At the same time, the concentration of short-chain fatty acids and the structure of the flora are regularly detected. According to the above-mentioned index detection results, the operating parameters are adjusted. When the above-mentioned indicators meet the requirements of the present invention, it can be considered that the closed reactor system is stable. Subsequently, the ion exchange capacity of the filler is detected every day. When it is lower than 30% of the initial ion exchange capacity, the chelating agent filler is replaced.

[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 Closed reactor operation effect of Example 1

[0092]

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

[0094] Embodiment 2:

[0095] The tripolyphosphate was loaded on the surface of chitosan particles by chemical grafting to prepare filler. The average particle size of the filler was 3.2 mm. The filler was loaded in a closed reactor with an effective volume of 1 L and a filler density of 20 kg chelating agent / m 3The sludge was hydrolyzed with hydrogen peroxide, and then the anaerobic acid production inoculation sludge was pretreated with a sulfonic acid-loaded filler for 8 hours, with a mass ratio of 1:1. Then 100 mL of the anaerobic acid production inoculation sludge was added to the closed reactor, and the volume ratio of the inoculation sludge to the closed reactor was 1:10. The start-up time was 5 days. Then, the sludge was continuously introduced into the closed reactor, with a feed flow rate of 200 mL / d and a solid content of 25 kg SS / m 3 At this time, the sludge loading rate in the closed reactor is 5kg SS / m 3 / d, the residence time is 5 days, and the mass relationship between the sludge treated every day and the chelating group of the filler is 1:4. In the closed reactor, the sludge is stirred at 45°C, and the stirring speed is 250rpm, so that the sludge and the filler are fully contacted and reacted, and the pH of the system is 6.9. At the same time, high-concentration organic wastewater is discharged in a continuous discharge manner, and the discharge flow rate is 200mL / d. During the operation of the closed reactor, the biogas production is monitored in situ, and high-concentration organic wastewater is discharged from the closed reactor every day. The activity of acetate kinase, butyrate kinase activity, and coenzyme F420 enzyme activity are detected. At the same time, the concentration of short-chain fatty acids and the structure of the flora are regularly detected. The operating parameters are adjusted according to the test results of the above indicators. When the above indicators all meet the requirements of the present invention, it can be considered that the closed reactor system is stable. Subsequently, the ion exchange capacity of the filler is detected every day. When it is lower than 30% of the initial ion exchange capacity, the chelating agent filler is replaced.

[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 Closed reactor operation effect 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 organic waste microecological flora 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 to obtain 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; 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 5~20kg SS / m 3 / d, the residence time of organic waste is ≥48h, and the mass ratio of organic waste to filler loaded with chelating group is 1:1.6-1:4.8, and then the mixed system a and organic waste are stirred at 100-300rpm. When the loading rate is 1-10kg SS / m 3 / d, react at 25-37℃, when the load rate is 5~20kg SS / m 3 / d at 45-60°C to selectively remove exchangeable and carbonate-bound metal ions in organic wastes, so as to carry out in-situ screening of microecological flora and anaerobic enrichment of short-chain fatty acids, 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 microecological flora of organic waste and anaerobic acid production enrichment based on selective metal ion removal according to claim 1, characterized in that: The chelating agent described in S1 is a compound having a cationic chelating group. The chelating groups in the filler loaded with the chelating group include tripolyphosphate, sulfonic acid, ethylenediaminediacetate, ethylenediaminetetraacetic acid, iminodiacetic acid and ethylenediaminedisuccinate. 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.

3. The method for in-situ screening of microecological flora of organic waste and anaerobic acid production enrichment based on selective metal ion removal according to claim 1, characterized in that: S1: acclimating 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.

4. The method for in-situ screening of microecological flora of organic waste and anaerobic acid production enrichment 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 in S2 are not within the above ranges, the above three parameters are made to meet the above ranges at the same time 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.

5. The method for in-situ screening of microecological flora of organic waste and anaerobic acid production enrichment 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 occurrence forms and contents in the organic waste, as well as the biogas production, enzyme activity, short-chain fatty acid concentration and bacterial community structure were measured. Every 1-3 days, 1g of the filler loaded with chelating groups was taken out to detect the ion exchange capacity. Among them: the content of soluble multivalent metals is reduced to <5mg / g SS, the content of exchangeable multivalent metals is reduced to <3mg / gSS, and the content of carbonate-bound multivalent metals is reduced to <0.1mg / g SS; Acetate kinase activity>20U / g SS, butyrate kinase activity>3.5U / g SS, coenzyme F420 enzyme activity<50U / g SS, acidogenic fermentation bacterial abundance>40%, methanogenic bacterial abundance<25%, biogas production<1m 3 / ton SS, short-chain fatty acid production>100kg COD / ton SS, when 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 above ranges are 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.

6. The method for in-situ screening of microecological flora of organic waste and anaerobic acid production enrichment 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 to 1:

9.

7. The method for in-situ screening of microecological flora of organic waste and anaerobic acid production enrichment based on selective metal ion removal according to claim 1, characterized in that: When the organic waste is kitchen waste or domestic waste, the organic waste in S2 is obtained by the following process: Dilute the initial organic waste with water to make the solid content of the diluted organic waste less than 50kg SS / m 3 , obtaining the organic waste.

8. A device for in-situ screening and anaerobic acid 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 microecological flora of organic waste and anaerobic acid production enrichment based on selective metal ion removal according to claim 1 comprises a closed reactor (3) of 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 length direction. Two honeycomb layered filler supports (4) are arranged in each reaction cell and are spaced apart from each other and fit with the inner wall thereof to form a spacer area. The filler supports (4) are 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 length 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 arranged in the spacer area of ​​each reaction cell. The first feed port (9) is connected to the outlet end of a first feed pump (19). The detection end of the temperature control device (6) is arranged in the reaction cell of the closed reactor (3); the closed reactor (3) is provided with a first discharge port (12), the first discharge port (12) is located at the other side of the length direction of the closed reactor (3); a flow passage (36) is provided between two adjacent reaction cells; the first feed port (9), all the flow passages (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 bucket; 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).

9. The device for in-situ screening and anaerobic acid production enrichment of microecological flora in sewage sludge or high-concentration organic wastewater based on selective metal ion removal according to claim 8, characterized in that: The closed reactor (3) is also 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 metal occurrence morphology and content in the 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 flora analyzer (30) are used to detect the concentration of short-chain fatty acids and the bacterial flora structure, respectively, and the ion exchange capacity detection platform (31) is used to detect the ion exchange capacity of the filler (2) loaded with chelating groups 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), and the deodorizing filler bag (34) is filled with activated carbon.

10. A device for in-situ screening and anaerobic acid enrichment of microecological flora of kitchen waste and domestic waste based on selective metal ion removal, characterized in that: The device for in-situ screening of microecological flora in sewage sludge or high-concentration organic wastewater and anaerobic acid production enrichment based on selective metal ion removal according to claim 9, further comprising an organic waste pretreatment tank (8) and a water storage tank (11) higher than the organic waste pretreatment tank (8); The organic waste pretreatment tank (8) is provided with a third stirring device. 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 to add food 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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