136 results about "Methanobacter" patented technology

The invention disclosure is a method of bioremediation of wastewater, particularly groundwater, by utilizing coupled anaerobic and aerobic biological treatment, more specifically, methanogenic (strictly anaerobic) and methanotrophic (strictly aerobic) microbial populations, in combination with a supply of in-situ generated water-dissolved oxygen and hydrogen. Water electrolysis is used to produce water-dissolved oxygen and hydrogen. The immediate advantage of using H2 from the electrolysis, is to provide electron donors to methanogens to reductively dechlorinate the chloroaliphatics, and to reduce the water carbonates and generate methane which is used as energy and carbon source for the methanotrophic bacteria. Oxygen is used as electron acceptor by the aerobic bacteria, including the methanotrophs. The addition of an organic carbon source can be minimized or even eliminated, so as to diminish the competition between methanotrophic bacteria and heterotrophic bacteria for oxygen.

The present invention relates to one kind of functional biological carbon fiber and its preparation process and application as biomembrane carrier. The biomembrane carrier is prepared with polyacrylonitrile carbon fiber, and through electrochemical surface treatment in 5-20 % concentration ammonium bicarbonate electrolyte to increase the surface acid oxygen containing functional groups and raise wettability, and gluing with water soluble epoxy resin in the amount 0.5-2 %. The biomembrane carrier can fix nitrobacteria, sulfate reducing bacteria and anaerobic methanogen. It may be used in treating high concentration acrylon waste water, and can eliminate sulfate, COD and ammonia nitrogen effectively. In addition, the biomembrane carrier is easy to regenerate and has no secondary pollution.

The present invention provides an apparatus for the dual production of hydrogen, wherein organic feed material of a primary hydrogen production apparatus is heated with excess or diverted heat from a secondary hydrogen production apparatus, thereby substantially deactivating or killing methanogens within the organic feed material. Hydrogen producing microorganisms contained or added to the organic feed material metabolize the organic feed material in a bioreactor to produce hydrogen in a primary hydrogen production apparatus. As the methanogens are no longer substantially present to convert produced hydrogen to methane, a biogas that contains hydrogen without substantial methane can be produced.

The invention discloses a method for improving output of methane produced by anaerobic digestion of inferior biomass raw materials, and belongs to the technical field of agricultural waste treatment. According to the method, various waste inferior biomass raw materials is used as a processing object, trace of electronic carrier hemin or vitamin K2 is added into an anaerobic reactor to improve the reducing force level of the whole fermentation system of biogas anaerobic fermentation so as to promote the growth and activity of hydrolytic acidification bacteria and methanogenic bacteria in the anaerobic digestion process, and the hydrolysis efficiency of the reaction system is improved, the anaerobic digestion time is shortened, and the yield of the methane and the conversion rate of the inferior biomass raw materials are improved. Due to the addition of extremely trace hemin and vitamin K2, industrial grade hemin and vitamin K2 are also applicable to the method, and the method has the advantages of simple operation and high efficiency and low cost, and is expected to be widely used in engineering practice.

The invention discloses a microbial fuel cell, a power generation device provided with the microbial fuel cell, and application of the power generation device provided with the microbial fuel cell in microbial power generation in a rice field. The microbial fuel cell comprises an anode, a cathode and a proton exchange membrane; the cathode comprises a catalyst, a conductive material and adhesive; the catalyst is manganese dioxide; and the proton exchange membrane is waterproof breathable cloth. The microbial fuel cell is used for manufacturing the power generation device, and the power generation device applied in the rice field can compete with methanogen in the rice field on organic substances so as to reduce the discharge amount of methane in the rice field, reduce the emission of greenhouse gas and contribute to the global climate.

The invention relates to the technology of biomass energy utilization, and aims to provide a kitchen waste and sludge hydrogen-producing acidification pretreatment method capable of increasing the methane production rate. The method comprises the following steps: mixing the kitchen waste and the sludge after crushing pretreatment, using the mixture and a sulfuric acid solution to prepare a mixed liquid, performing hydrolysis on the mixed liquid at 135 DEG C to obtain a starting crude; adding yeast powder into the starting crude, inoculating dark-fermentation hydrogenogens, feeding high-purity nitrogen to build an anaerobic fermentation environment, then performing dark-fermentation hydrogen-producing deep acidification pretreatment at the constant temperature of 37 DEG C, and obtaining a hydrogen-producing deep acidification pretreatment liquid; adding methanogens into the liquid, keeping the anaerobic environment at 37 DEG C, and performing methane fermentation and coproduction. According to the method disclosed by the invention, the hydrogen-producing deep acidification pretreatment is utilized to obviously increase the methane production rate; the rate peak time of the produced methane is reduced by about 50%; the waste treatment and degradation time of the fermentation tank with a unit volume is reduced by about 50%; the waste treatment capacity of the single equipment in unit time is improved by about one time.

The invention discloses a method for improving the activity of methanogens while reducing high-concentration ammonia nitrogen in the anaerobic process, and belongs to the field of water treatment. The method comprises the following steps of: contacting high-concentration nitrogen-containing organic waste water with anaerobic microorganisms fully in an anaerobic reactor to perform reaction, and degrading to obtain a large amount of ammonia nitrogen; introducing the waste water into a crystallizing sedimentation tank partially, adding a dissoluble magnesium source and phosphates in a certain ratio, and regulating the pH value to 7.0 to 10.0, so that Mg<2+>, NH4<4+> and PO4<3-> in the waste water react to generate an ammoniomagnesium phosphate (MAP) crystal, and precipitating the MAP crystal; and stabilizing the pH value of treated supernatant to 6.5 to 8.0 by a pH regulating tank, and refluxing to the anaerobic reactor. By the method, ammonia nitrogen resources in the waste water can be recovered effectively, the phenomenon of the reduction of the activity of anaerobic sludge due to overhigh concentration of the ammonia nitrogen can be prevented, and the operation effect of the anaerobic reaction and the yield of methane can be improved.

A system for the efficient conversion of plant biomass to methane is provided, where the conversion includes use of a thermophilic methanogenic consortium containing a cellulolytic thermophile, an acetate-oxidizing thermophile and a thermophilic methanogen, the combination of which hydrolyzes hexoses and pentoses, oxidizes acetate and provides a hydrogen sink, to convert plant biomass to the theoretical limit of bioenergy.

The invention discloses a method for promoting methanogens to produce methane by utilizing dissimilatory metal reduction bacteria. The method comprises the following steps of: gathering the dissimilatory metal reduction bacteria by taking anaerobic sludge, benthal deposits and / or sewage as inoculants; screening and gathering the methanogens by taking the anaerobic sludge and / or the benthal deposits as inoculants; concentrating the dissimilatory metal reduction bacteria obtained through gathering, then mixing with the methanogens inoculants and anaerobic digesting sludge according to a certain proportion, placing into an anaerobic fermentation tank, and fermenting by taking organic wastes as raw materials to produce the methane. The method disclosed by the invention solves the problem that the methanogens can not utilize a large quantity of small-molecule organic compounds (such as glucose, amino acid, butyric acid, propanoic acid, lactic acid, ethanol and the like) which are generated through hydrolysis and fermentation and increases the methane generation amount in a fermentation process and the transformation rate of organic substances transformed into the methane, thereby having very good application prospect on the aspect of producing the methane through anaerobic fermentation.

The invention relates to a compound biological agent for enabling an acidified marsh gas fermentation system to restore gas production and a preparation method thereof. The compound biological agent contains acidophilus acid-resistant methane-producing bacteria, syntrophic acetic acid oxidation bacteria and minor elements. The compound biological agent enables an acidified marsh gas fermentation system to quickly restore normal gas production without adding alkaline substances or performing massive material discharging or changing, thus ensuring continuous stable gas production of the marsh gas fermentation system. The invention also provides a preparation method of the compound biological agent, which comprises the following steps: under anaerobic conditions, mixing a mixed bacterium solution of acidophilus acid-resistant methane-producing bacteria and a mixed bacterium solution of syntrophic acetic acid oxidation bacteria to obtain a compound bacterium solution, concentrating until the total concentration of cells of the acidophilus acid-resistant methane-producing bacteria and the syntrophic acetic acid oxidation bacteria is at least 1*10<9> / mL, and then adding the minor elements; and packaging, preserving at low temperature, and preparing into the liquid compound biological agent for enabling an acidified marsh gas fermentation system to restore gas production. A solid agent can be further prepared by stirring and mixing with auxiliary materials and then performing anaerobic drying.

The invention discloses a method for production increasing of coal-bed gas through combination of heat injection decomposition and microbial degradation, and belongs to the technical field of coal-bed gas mining. The method comprises the three steps of high-temperature heat-resistant methanogen enrichment culture, heat injection decomposition and microbial degradation for production increasing of the coal-bed gas, coal structure decomposition at the high temperature is realized through heat injection, and thus microbial degradation of coal is promoted so as to increase the recovery ratio of the coal-bed gas. Through heat injection, on the one hand, the coal structure is changed, organic matter in the coal is dissolved, microbial degradation is facilitated, and the speed of biological reaction is increased; and on the other hand, the permeability of a coal seam is improved, an channel is opened for a coal seam injection bacterium group, a methane flow channel is unblocked, the coal-bed gas and the bacterium group are transported in the coal seam advantageously, and the recovery ratio of the coal-bed gas is increased.

The invention discloses a device and a method for domestic sewage treatment. The method includes the steps of precipitation digestion, anaerobic reaction, aerobic biological degradation and reprecipitation. The anaerobic reaction performed segmentally includes a hydrolytic acidification segment and two methanogenesis segments, so that different microorganisms give full play to pollutant degradation capabilities in respective suitable environemts, particularly, corresponding spatial environments are provided for different methanogens, and conditions are created for respective advantage growth. In the aerobic biological degradation step, biological membranes are attached to thin-layer water to contact with air sufficiently, and absorption of oxygen in the air is strengthened. During large sewage quantity, the aerobic biological membranes contact with the air and sewage alternately; and during small sewage quantity, the thin-layer water on the surfaces of the biological membranes contacts with the air continuously. Compared with the prior art, the device for domestic sewage treatment has the advantages of optimized spatial arrangement of function units, compact structure, good sewage treatment effect, no energy consumption, avoidance of personnel operation, high process space utilization rate and occupied area saving.

The present invention provides a method for generating methane from a carbonaceous feedstock with simultaneous in situ sequestration of carbon dioxide to afford a biogas comprising at least 85 percent by volume methane, the method comprising anaerobically incubating a particulate additive in contact with a carbonaceous feedstock in a neutral or alkaline aqueous culture medium containing a culture of methanogenic consortia and collecting methane generated therefrom. The additive comprises at least one material selected from a biochar, an ash produced by gasification or combustion of a carbonaceous material, a black carbon soil, and a Terra Preta soil.

The invention relates to a composite biological agent for moderate temperature biogas fermentation high content volatile fatty acid in pig manure waste and a preparation method thereof. The compositebiological agent is prepared from methanogen, moderate temperature syntrophism acetate oxidized bacteria, moderate temperature syntrophism propionate oxidized bacteria, moderate temperature syntrophism butyric acid oxidized bacteria, trace element and vitamin. The composite biological agent enables an acidifying biogas fermentation system using pig manure as a raw material to rapidly and effectively recover to produce biogas normally and to run continuously and stably. The invention further provides the preparation method of the composite biological agent. According to the method, raw materials pig manure inoculant and pig manure are optimized and enriched in a culture medium under anaerobic condition at 37DEG C by increasing sodium acetate, sodium propionate and sodium butyrate level by level, then are concentrated, ammonium chloride, magnesium sulfate, potassium chloride, calcium chloride, yeast powder, sodium acetate, sodium propionate and sodium butyrate are added, then the productis packaged and preserved at low temperature so as to prepare a liquid composite biological agent. Further, the liquid composite biological agent can be mixed with auxiliary materials and then is dried under the anaerobic condition at 37DEG C so as to prepare the solid composite biological agent.

The invention relates to an efficiency improving method for a biochar addition-based anaerobic membrane bioreactor. The method comprises the following steps: 1, preparing walnut shell biochar; 2, adding the walnut shell biochar prepared in step 1 into an anaerobic membrane bioreactor which is successfully started, and taking another reactor which is not added with the walnut shell biochar as a control group; and 3, operating the reactor, operating the reactor for one cycle when the HRT is 30 d, then increasing the organic load, enabling the reactor to operate for one cycle when the HRT is 20 d, and regularly measuring various indexes in the reactor. Free syntrophic flora in a biochar enrichment fermentation system is utilized, and oxygen-containing functional groups on the surface of the biochar are utilized to excite direct electron transfer between interspecies of syntrophic methanogens, so that the kitchen waste treatment efficiency of the anaerobic membrane bioreactor is improved. At the same time, the adsorption conversion effect of the biochar on free macromolecules reduces the potential of the biochar on the membrane pollution and plugging effect, and the scouring effect of the biochar on the membrane during aeration also reduces the membrane pollution rate.

The invention relates to a method for increasing the biological gasification rate of oil reservoir residual oil. The method includes the following steps that firstly, an electrode is constructed in an oil reservoir; secondly, an aqueous solution of an anaerobic microbial activator is injected into the oil reservoir; thirdly, a micro-electric field is formed in the oil reservoir by applying voltage to the electrode so as to stimulate proliferation and metabolism of methanogens and syntrophism metabolic bacteria of the methanogens; fourthly, application of the voltage stops, a water-containing liquid is injected into the oil reservoir, and the methanogens and the syntrophism metabolic bacteria are displaced to the deep part of a stratum; fifthly, a well is opened to produce methane. The invention further relates to application of the method.

The invention discloses a method for anaerobic preparation of methane from landfill leachate, and belongs to the field of methane preparation methods. The method comprises the steps of influent concentration control over the landfill leachate, inoculation of anaerobic sludge in an anaerobic baffled reactor, addition of ferroferric oxide, comprehensive management and control over relevant parameters and hydraulic retention time in the anaerobic baffled reactor, detection of the relevant parameters in the anaerobic baffled reactor, and determination of the total gas production and the methane proportion in the anaerobic baffled reactor. According to the method, the direct electronic transfer process between conductive bacteria and methanogenic bacteria in the anaerobic sludge is driven through the interaction between ferroferric oxide conductive materials and microorganisms in the anaerobic sludge, the anaerobic preparation of the methane from the landfill leachate is strengthened, and efficient anaerobic treatment and effective degradation of high molecular refractory organics in the landfill leachate are achieved.

The invention discloses a synchronous methanogenesis and aerobic methane oxidation coupling denitrification process control method. The method comprises the following steps: (1) establishing a reaction system; (2) carrying out microbial culture; (3) enriching anaerobic methanogens; (4) enriching aerobic methane oxidizing bacteria; and (5) enriching denitrifying bacteria, removing 91.4%-98.8% of COD, 93.2%-99% of NO3-N and 71%-93.5% of TN by a system under the process condition, and ensuring that the methane recovery amount is 180-660mL / d. The method is economical and efficient, and good socialand economic benefits can be generated. The organic and nitrogen pollutants in the wastewater are removed, the greenhouse effect of effluent soluble methane is eliminated, and meanwhile part of gaseous methane can be recycled.

The invention discloses a sequencing batch electrode polarity reversal microbial fuel cell and belongs to the technical field of sewage treatment and resourcing in environment engineering. The sequencing batch electrode polarity reversal microbial fuel cell comprises two symmetrical SBR reactors and a middle gasket for fixing an exchange membrane. The SBR reactors are used as half cells. Motors are installed on tops of the SBR reactors. In anaerobic and anoxic stages, the motors drive stirring bars to carry out stirring. In an aerobic stage, an aeration process is carried out by aeration heads at the bottoms of the SBR reactors and gas is discharged by gas vents above liquid levels in the SBR reactors. A carbon material as an electrode is connected to an external circuit. Water is fed by water inlets and outlet water is discharged by water outlets. The SBR reactors are used as the half cells so that operation is flexible. Through current-producing bacterium biological membrane catalytic anodic and cathodic reactions, pollutants are degraded and electric energy is produced. Electrode compartment sequencing batch operation causes electrode polarity reversal and alleviates pH gradient-caused overpotential. In the aerobic stage, methanogen growth is inhibited and an electric energy recovery rate is improved. In the anaerobic and aerobic stages, phosphor removal can be realized.

The invention relates to an anaerobic fermentation hydrogen production method using excess sludge as raw material, and an additive. The hydrogen production method comprises the following steps: S1, using excess activated sludge generated by a sewage treatment plant as raw material, settling and removing supernatant of the excess activated sludge to obtain anaerobically fermented raw material; s2,adding the anaerobically fermented raw material into a fermentation reactor, adding ferrate, stirring uniformly, and keeping an anaerobic environment in the fermentation reactor; and S3, controlling the temperature, continuously carrying out a fermentation reaction, and continuously outputting or intermittently outputting generated hydrogen. Compared with the prior art, the hydrogen production method adopts the ferrate, which not only can destroy the structure of the excess sludge and promote the release of a large quantity of biodegradable organic matters in the sludge, but also can significantly inhibit and reduce the activity and abundance of hydrogen-consuming microorganisms such as hydrogen-phagocytosis methanogens, and thereby significantly promotes the amount of hydrogen produced byfermentation of the excess sludge; the operation is simple, and the long-term operation management is facilitated; and the hydrogen production quantity of the residual sludge resources can be obviously increased.

The invention discloses a domestication method of an ammonia nitrogen and propionic acid resisting methane production strain. The ammonia nitrogen and propionic acid resisting methane production strain comprises a propionic acid oxidization flora, a syntrophaceae propionic acid oxidization flora, an acetic acid cracking methane production flora, a hydrogen nutrition type methane production flora and a denitrification flora. The method takes marsh gas fermentation liquid as an inoculum, takes propionic acid as a carbon source and takes urea or NH4Cl as an ammonia nitrogen source; the marsh gas fermentation liquid is domesticated through a method for alternately improving the concentration of the propionic acid and the concentration of ammonia nitrogen, so as to obtain the ammonia nitrogen and propionic acid resisting methane production strain; the strain can stably produce gas for a long period under the conditions that the concentration of the ammonia nitrogen is more than 3.0g / L and the concentration of the propionic acid is more than 2.0g / L; the gas yield is 60 percent more than a theoretical yield; the utilization rate of the propionic acid and acetic acid is more than 90 percent; the ammonia nitrogen and propionic acid resisting methane production strain has the advantages of high impact resistance, high stability of biological enhancing effect and the like, and can be used for removing comprehensive inhibition of the ammonia nitrogen and the propionic acid in a marsh gas fermentation process and improving the fermentation performance of marsh gas.

The invention discloses a separation method of butyric acid oxidized hydrogen-producing acetogenic dominant microorganisms, relating to a separation method of hydrogen-producing acetogenic bacteria and solving the problems that the traditional separation method is difficult to separate and the hydrogen-producing rate of the cultured hydrogen-producing acetogenic bacteria is low. The separation method comprises the following steps of: firstly, preliminarily domesticating anaerobic activated sludge; secondly, preparing a bacterial suspension A; thirdly, enriching a back bacterial suspension; fourthly, enriching and culturing the enriched back bacterial suspension again; fifthly, preparing compound microorganisms of butyric acid oxidized hydrogen-producing acetogenic bacteria and methanogen; sixthly, preparing the butyric acid oxidized hydrogen-producing acetogenic microorganisms; seventhly, transferring the butyric acid oxidized hydrogen-producing acetogenic microorganisms to a butyric acid culture medium for vibration velocity culture; and eighthly, repeating the step seven for 3-6 times and then separating. The method has easy separation and simple operation, and the hydrogen-producing rate of the separated dominant microorganisms is about 7-10 times of that of the hydrogen-producing bacteria. The advantageous bacterium group not only can degrade the butyric acid with higher concentration, but also can effectively improve the treating efficiency of organic wastewater with high concentration.

The invention discloses an integrated vertical high-concentration sulfate wastewater treatment device. The device comprises a hydrolytic acidification reaction section, a hydrogen sulfide stripping section, a methanogenesis reaction section and a tank body, wherein the hydrolytic acidification reaction section is arranged at the lower section of the tank body, and includes a bottom water distribution pipe used for uniformly distributing high-concentration sulfate wastewater and a first filler layer used for providing a growth environment for sulfate reducing bacteria; the hydrogen sulfide stripping section is arranged at the middle section of the tank body and comprises a stripping pipeline and a gas collecting part; and the methanogenesis reaction section is arranged at the upper sectionof the tank body and comprises a second filler layer for providing a growth environment for methanogens and an effluent weir arranged along the circumference of the tank body. According to the invention, the anaerobic reaction is divided into the hydrolytic acidification reaction section and the methanogenesis reaction section, and the hydrogen sulfide stripping section is additionally arranged between the hydrolytic acidification reaction section and the methanogenesis reaction section, so that the inhibition effect of hydrogen sulfide on methanogens is weakened, the activity of the methanogens is guaranteed, and the treatment effect on high-concentration sulfate wastewater is improved.

The invention discloses a device and process for reinforcing zero-valent iron to degrade kitchen waste based on a dynamic magnetic field. The process comprises the following steps that the kitchen waste is crushed, the crushed kitchen waste is put into an anaerobic reactor inoculated with introduction sludge, the zero-valent iron is added into the reactor according to the adding amount of 10g / L, a dynamic magnetic field device below the anaerobic reactor is started, the dynamic magnetic field is composed of a rotary shaking table and a strong magnet. According to the device and process for the reinforcing zero-valent iron to degrade the kitchen waste based on the dynamic magnetic field, direct interspecific electron transfer of microorganisms in the anaerobic reactor is promoted by utilizing a conductor and an induced electric field generated by the conductor capable of cutting magnetic induction lines, and meanwhile, a weak magnetic field can accelerate dissolution of the zero-valent iron, promote activity of anaerobic microorganisms and change a microbial community structure, so that methanogens are enriched; and the process of degrading the kitchen waste to produce methane by the anaerobic reactor is enhanced. According to the device for the reinforcing zero-valent iron to degrade the kitchen waste based on the dynamic magnetic field, the problems that the anaerobic reactor for treating the kitchen waste is easy to acidify and the methane production efficiency is low can be solved.

Methods, microbial fuel cells and microbial consortia for generating electrical current are provided according to the present invention which include providing a microbial consortium to an anode chamber of a microbial fuel cell, wherein the microbial CN consortium includes: 1) an engineered methanogen that contains a heterologous nucleic acid sequence encoding methyl-coenzyme M reductase derived from an anaerobic methane oxidizer, 2) an exoelectrogen microbe that produces electrically-conductive appendages and / or one or more types of electron carrier, and 3) a sludge, methane-acclimated sludge, a sludge isolate component, a methane-acclimated sludge isolate component chosen from Paracoccus spp., Geotoga spp., Geobacter spp., Methanosarcina spp., Garciella spp., humic acids; or a combination of any two or more thereof.

The invention relates to the field of wastewater treatment, in particular to application of charcoal particles in acclimatization of anaerobic activated sludge, the anaerobic activated sludge and an acclimatization method and application of the anaerobic activated sludge. The method comprises the following steps: mixing bottom mud with charcoal particles, and introducing wastewater for domestication to obtain anaerobic activated sludge. Based on the basic principle of DIET (Direct Inter-specific Electron Transfer) between organic acid metabolic bacteria and methanogens, biochar is introduced into to-be-domesticated bottom mud, DIET for producing methane in anaerobic digestion is constructed and strengthened, electron transfer between hydrolysis acidification bacteria and methanogens is promoted, conversion from VFA to methane is realized, and acidification of reaction is effectively inhibited from the source.

The invention discloses an MABR and CH4MBfR combined device for treating p-nitrophenol-containing wastewater. The device comprises a wastewater storage device, an MABR device and a CH4-MBfR device which sequentially communicate with one another, and an intermediate water outlet tank is connected between the MABR device and the CH4-MBfR device. According to the invention, the advantages of the twomembrane reactors are fully combined, p-nitrophenol can be effectively degraded, deep denitrification is realized, and the effluent is discharged after reaching the standard. As the MABR adopts bubble-free aeration, the oxygen utilization rate is high and can reach 100%, the oxygen mass transfer range is relatively small, the toxicity is reduced under the action of hydrolytic acidification and thelike of anaerobic layer florae, and then metabolism mineralization degradation is conducted through aerobic and facultative layer florae; and a denitrification type methane anaerobic oxidation florabiological membrane in the CH4-MBfR main body reactor can be used for effective and deep denitrifying, a large amount of methane flora exists in the microbial membrane, part of methane can be suppliedto the biological membrane, the adding cost of a carbon source is saved, and the emission of methane greenhouse gas is reduced.

The invention relates to a screening technique of anaerobic degraded petroleum hydrocarbon methanogens. The method includes steps of taking oil field produced liquid and oil-containing sludge as samples, and performing anaerobic culture on flora therein; applying petroleum hydrocarbon as a carbon source of flora in the absence of carbon source and further cultivating and screening flora using the petroleum hydrocarbon as the carbon source. Meanwhile, the method uses the oil field produced liquid and oil-containing sludge as samples simultaneously to obtain the degraded petroleum hydrocarbon mixed flora with stronger adaptation, and respectively screen samples of which gas yields are more than 0.4 mu mol / d and 1.15 mu mol / d according to different properties of the oil field produced liquid and flora in oil-containing sludge; the samples are further mixed, so that the mixture for degrading petroleum hydrocarbon mixed flora is obtained.

The invention relates to a method for improving anaerobic digestion of waste oil and fat to produce methane through saponification pretreatment. The method comprises the following steps: carrying outsaponification reaction on waste oil and fat and calcium ions at room temperature under an alkaline condition in a calcium / oil molar ratio of 0.25-1, adding generated calcium soap into an anaerobic digestion reactor, adding an inoculum to enable the ratio of the calcium soap to the inoculum to be 0.5 (gVS / gVS), and carrying out anaerobic digestion under the conditions that the temperature is 35-37DEG C and the rotating speed is 150 rpm. Degradation of long-chain fatty acids in the oil and fat is promoted, and the methane yield is increased. Compared with the prior art, the method has the advantages that the methane production rate of the waste oil and fat is increased, the inhibition effect of long-chain fatty acids is relieved, the activity of anaerobic digestion for methane production is improved, and the method is easy to implement.