CN112501214B

CN112501214B - Two-phase anaerobic treatment system and method for reinforcing wet garbage in villages and towns

Info

Publication number: CN112501214B
Application number: CN202011333378.5A
Authority: CN
Inventors: 刘建伟; 陈欣玥; 臧娜娜; 冯文韬
Original assignee: Beijing University of Civil Engineering and Architecture
Current assignee: Beijing University of Civil Engineering and Architecture
Priority date: 2020-11-24
Filing date: 2020-11-24
Publication date: 2022-05-17
Anticipated expiration: 2040-11-24
Also published as: CN112501214A

Abstract

The invention discloses a system and a method for strengthening two-phase anaerobic treatment of wet garbage in villages and towns, which comprises wet garbage pretreatment, straw pretreatment and two-phase anaerobic fermentation treatment; the invention adopts directional sorting treatment to carry out the pretreatment of wet garbage, obtains high-purity organic garbage components, mixes the high-purity organic garbage components with the straws in a reasonable proportion, and carries out independent hydrolysis acid production reaction and independent methane production reaction, thereby having good treatment effect, good integration degree of a treatment system and greatly improving the resource utilization rate.

Description

Two-phase anaerobic treatment system and method for reinforcing wet garbage in villages and towns

Technical Field

The invention relates to the field of garbage treatment, in particular to a wet garbage reinforced two-phase anaerobic treatment system and a method.

Background

With the rapid development of rural economy, the living standard of residents is continuously improved, the production amount of domestic garbage in villages and towns is increased day by day, more than half of the domestic garbage is wet garbage consisting of organic components such as kitchen waste and the like, the wet garbage has high water content and high organic matter and grease content, is easy to ferment, deteriorate and rot, and is easy to grow pathogenic microorganisms and emit malodorous gas after being placed for a long time. The classification effect of wet garbage in villages and towns is poor, other components can be mixed in the wet garbage, and substances such as courtyard garbage, branches and leaves, grass and the like can be mixed in the wet garbage. If not properly handled, it can seriously affect environmental hygiene and human health. Meanwhile, the wet garbage is mainly characterized by containing other garbage components due to incomplete front-end classification, cellulose, hemicellulose and lignin substances such as vegetable stems, leaves, branches and leaves of trees and the like, and oil in the wet garbage. At present, the treatment is mainly carried out by landfilling, incineration, conventional composting and the like.

However, the above methods have the following disadvantages, respectively: the landfill technology is not suitable for treating wet garbage, can not realize the reclamation of the wet garbage, occupies a large amount of land, and leachate generated during the landfill pollutes soil and underground water to cause secondary environmental pollution. Although the incineration treatment has small occupied area and good volume reduction effect, wet garbage has high water content and low heat value, auxiliary fuel needs to be added, a large amount of waste gas and waste residue can be generated in the incineration process, and particularly toxic by-product-dioxin gas can be generated to cause secondary pollution. Conventional compost treatment needs a large field, the compost fermentation period is long, the efficiency is low, the quality of the unevenly fermented organic fertilizer is unstable, the finished organic fertilizer needs drying equipment, the energy consumption and the environmental pollution are increased, the problems of waste gas and odor pollution are caused in open type fermentation treatment, the treatment effect of leachate is poor, and secondary pollution is caused. Compared with the conventional solid waste treatment technologies such as landfill, composting and incineration and the like, the anaerobic fermentation is a technology which can effectively convert organic waste into methane so as to be used as gas fuel, and the biogas residues generated after the anaerobic fermentation can be further processed into high-quality fertilizers while generating clean energy, so that the method is a feasible new resource-based environment-friendly technology.

However, since the wet garbage contains cellulose, hemicellulose and lignin substances such as vegetable stems and leaves, branches and leaves of trees and the like, and possibly contains grease, the treatment effect is not high by adopting the conventional anaerobic fermentation technology, and the recycling effect is poor.

Disclosure of Invention

The purpose of the invention is as follows: one of the purposes of the invention is to provide a two-phase anaerobic treatment system for reinforcing wet garbage in villages and towns, which improves the treatment efficiency and the resource utilization effect of the system; the invention also aims to provide a two-phase anaerobic treatment method for reinforcing the wet garbage in villages and towns.

The technical scheme is as follows: the invention provides a reinforced two-phase anaerobic treatment method for wet garbage in villages and towns, which comprises wet garbage pretreatment, straw pretreatment and two-phase anaerobic fermentation treatment;

wherein the wet waste pretreatment comprises: manually sorting and removing interferents in the wet garbage, then carrying out solid-liquid separation treatment to obtain pre-dewatered garbage, screening the pre-dewatered garbage, then carrying out directional sorting treatment according to components contained in the garbage with different particle sizes, and removing metals, plastics, fibers and inorganic matters to obtain sorted organic garbage; crushing the organic garbage to obtain a crushed material, and then carrying out sorting treatment on stems and leaves and glass to obtain high-purity organic garbage with cellulose-containing substances and glass removed from the stems and leaves;

the straw pretreatment comprises the following steps: crushing the straws to obtain crushed substances with the size less than 5mm, blending the crushed substances to remove lignin substances, and then drying to obtain pretreated straws;

the two-phase anaerobic fermentation treatment comprises the following steps: mixing the pretreated straws with the organic garbage obtained by the wet garbage pretreatment, and adding a compound bacterial liquid to obtain a mixed material; sending the mixed material to a hydrolysis acidification area, and adding hydrolysis acidification bacteria to perform hydrolysis acidification reaction; and (3) feeding the hydrolytic acidification liquid formed by the hydrolytic acidification reaction into a methanogenic area, and adding methanogenic bacteria liquid to perform anaerobic fermentation reaction.

The treatment method also comprises sewage treatment, wherein the treated sewage is sewage subjected to oil-water separation treatment, biogas slurry subjected to centrifugal treatment and separation and sewage of each garbage treatment unit; the sewage is treated by adopting a coagulation air flotation-high load aeration tank-two-stage A/O-MBR process, the effluent is reused for a two-phase anaerobic fermentation system and a straw pretreatment system to adjust the humidity, one part of sludge flows back to a front-end first-stage denitrification tank, after the residual sludge is subjected to concentration treatment and deep dehydration, the generated clear liquid flows back to the first-stage denitrification tank, and the generated slag cake and sludge cake flow back to be hydrolyzed.

Wherein, the wet garbage pretreatment comprises the following steps:

(1) manually sorting and removing interferents in the wet garbage, wherein the interferents comprise plastic, glass, metal and other large substances;

(2) carrying out solid-liquid separation treatment on the residual wet garbage after manual sorting treatment to obtain pre-dehydrated garbage and oily wastewater; carrying out impurity separation on oily wastewater through a pipeline filter, then carrying out oil-water separation treatment, extracting oil, processing to prepare industrial oil, and feeding the wastewater into a sewage treatment system;

(3) performing primary screening treatment on the pre-dehydrated garbage obtained in the step (2) to obtain undersize products with the particle size smaller than 40mm and oversize products with the particle size larger than 40mm, performing magnetic separation treatment on the oversize products, separating metal garbage from the garbage under the action of magnetic force, performing air separation treatment on the residual garbage after magnetic separation, and performing air separation by utilizing the weight difference among the components to obtain medium materials containing organic components;

(4) performing secondary screening treatment on the primary screening undersize obtained in the step (3) to obtain undersize with the particle size smaller than 8mm and oversize with the particle size larger than 8mm, and collecting the undersize and then performing landfill treatment;

(5) and (3) crushing the medium material obtained in the step (2) and the secondary screening oversize material obtained in the step (3) to obtain a crushed material with the particle size of less than 20mm, and carrying out separation treatment on the crushed material by using stems and leaves and glass to obtain the residual organic garbage without the stems and leaves containing cellulose substances and glass.

Preferably, in the two-phase anaerobic fermentation treatment process, the composite bacterial liquid comprises trichoderma and bacillus. Adding composite bacteria consisting of trichoderma and bacillus with the bacterial quantity ratio of 1: 1 and the bacterial liquid concentration of 4.5 multiplied by 10⁸CFU/mL, the microbial community can degrade cellulose and lignin contained in the corn straws and the organic garbage, and the microbial community and acid-producing bacteria and methanogen have synergistic effect, so that the degradation rate of the organic garbage can be improved, the system stability is effectively improved, and the mixed material is sent to a hydrolysis acidification tank.

Preferably, the temperature of the hydrolysis acidification reaction is 35-38 ℃, and the pH value is 6.5-7.8; the temperature of the anaerobic fermentation reaction is 55-58 ℃, and the pH value is 7.0-7.5.

In the two-phase anaerobic fermentation treatment process, hydrolysis acidification reaction is carried out under the condition of medium temperature (35-38 ℃), and methanogenesis reaction is carried out under the condition of high temperature (55-58 ℃), wherein the medium temperature-high temperature system has the highest methane yield and VS removal rate, and the richness, diversity, uniformity and dominance degree of the bacterial community structure are also the best.

In the two-phase anaerobic fermentation treatment process, hydrolysis acidification reaction is carried out under the condition that the pH value is 6.5-7.8, methane production reaction is carried out under the condition that the pH value is 7.0-7.5, the hydrolysis acidification zone mainly carries out acetic acid and butyric acid type fermentation in the pH range, a more favorable substrate can be provided for the subsequent methane production process, wet garbage has higher hydrolysis and acidification rates, the VFA yield is 2 times of that of the garbage without pH adjustment, the methane production amount is sensitive to the pH value, and the methane production amount is the highest when the pH value is 7.

Preferably, in the straw pretreatment, KOH and Ca (OH) are adopted in the blending treatment₂Performing combined pretreatment; the VS ratio of the mixture of the pretreated straws and the organic garbage is 1: 3-5.

KOH and Ca (OH)₂The combined pretreatment can effectively remove lignin in the corn straws, destroy the wood fiber structure of the straws, increase the accessibility of the matrix, facilitate the hydrolysis of enzyme and improve the conversion rate of anaerobic fermentation.

The treated straw and the organic garbage are mixed according to the mixing ratio of 1: 3-5, the mixing ratio of the straw and the organic garbage can be adjusted to the optimal C/N ratio of 15-20 on the characteristic of raw materials, and the matching of acid production rate and methane production rate is adjusted on the fermentation dynamics, so that the fermentation process is more stable.

Preferably, part of digestion liquid of anaerobic fermentation reaction in the methanogenesis area directly flows back to the hydrolysis acidification area for fermentation, and the backflow part accounts for 20-30% of the total volume of the digestion liquid; and carrying out solid-liquid separation treatment on the residual digestive juice to separate biogas residues and biogas slurry, drying and granulating the crushed biogas residues, and carrying out sewage treatment on the biogas slurry.

The digestion solution which is not subjected to solid-liquid separation is recycled to the hydrolysis acidification tank to adjust the solid content, so that the discharge of the digestion solution can be reduced, the pH value of a hydrolysis acidification zone is in a range suitable for the survival of flora, the COD removal effect is better, and the methane content is higher when the recycling proportion is 20-30%.

In the prior art, due to incomplete classification, when wet garbage in villages and towns is treated by using a conventional process, only simple pre-sorting is carried out, sorted materials are rough, the sorting rate and the purity of the wet garbage are not high, and impurities with different components have great influence on the subsequent anaerobic fermentation treatment and the recycling effect of the wet garbage; courtyard organic wastes such as leaves are often mixed in the existing wet garbage of villages and towns, cellulose, hemicellulose, lignin and other refractory components in the wet garbage are lack of separation and treatment on cellulose components in the wet garbage, and the garbage often contains a large amount of cellulose, lignin and other substances for inhibiting anaerobic fermentation, so that the efficiency of a later-stage anaerobic fermentation process is adversely affected; the wet garbage in villages and towns usually has high water content and organic matter content, C, N is unbalanced, the wet garbage is extremely easy to hydrolyze rapidly in two-phase anaerobic fermentation, and a large amount of volatile fatty acid is accumulated, so that the system is over-acidified, and the activity of methanogenic bacteria is inhibited. The straw is added into the wet garbage, so that the alkaline buffer capacity of the fermentation system can be effectively improved, and the C/N ratio and the nutrient components of the system can be adjusted, so that the efficiency and the stability of the fermentation system are improved.

The invention adopts the directional sorting treatment technology to sort the garbage with different components in the wet garbage, separates the organic components capable of anaerobic fermentation, removes the substances difficult to biodegrade in the wet garbage, and utilizes cellulose in the sorted organic garbage to degrade the cellulose substances, thereby improving the anaerobic fermentation efficiency of the organic garbage and stabilizing the fermentation process; the straws are pretreated, wet garbage is reasonably mixed, the optimal C/N ratio is adjusted, and the anaerobic conversion efficiency of organic matters is improved; the anaerobic reaction process is divided into an independent hydrolysis acidogenesis stage and a methane production stage which are connected in series in a certain form, so that a complete anaerobic fermentation process is realized, the effects of hydrolysis acidification and methanation are optimized simultaneously, and the treatment capacity of the system and the operation stability of the reactor are greatly improved.

The invention also provides a village and town wet garbage reinforced two-phase anaerobic treatment system, which comprises a wet garbage pretreatment system, a straw pretreatment system, a two-phase anaerobic fermentation system and a sewage treatment and reflux system;

the wet garbage pretreatment system comprises a sorting table, a pre-dehydration device, a water-oil separation device, a primary drum sieve, a magnetic separator, a winnowing machine, an electrostatic separation machine, a secondary drum sieve, a hammer impact crusher, a stem-leaf separation machine and a glass separation machine, wherein the primary drum sieve and the secondary drum sieve are respectively provided with an oversize material discharge port and an undersize material discharge port, the magnetic separator is provided with a magnetic material discharge port and a nonmagnetic material discharge port, and the winnowing machine is provided with a light material discharge port, a medium material discharge port and a primary heavy material discharge port. Furthermore, the wet garbage pretreatment system comprises a sorting table, a pre-dehydration device, a primary drum screen, a secondary drum screen, a hammer type impact crusher, a stem and leaf separator and a glass separator which are sequentially connected, wherein a screen underflow discharge port of the primary drum screen is connected with a feed port of the secondary drum screen, a screen overflow discharge port of the primary drum screen is connected with a feed port of a magnetic separator, a nonmagnetic material discharge port of the magnetic separator is connected with a feed port of a winnower, a medium material discharge port of the winnower and a screen overflow discharge port of the secondary drum screen are both connected with a feed port of the hammer type impact crusher, and a light material discharge port of the winnower is connected with a feed port of an electrostatic separator;

the straw pretreatment system comprises a double-roller crusher, a blending tank and a first dryer which are connected in sequence;

the two-phase anaerobic fermentation system comprises a hydrolysis acidification tank and a methane production tank which are communicated with each other, and the discharge ports of the first dryer and the glass separator are connected with the feed port of the hydrolysis acidification tank;

the sewage treatment and reflux system comprises a regulating tank, an air flotation tank, a high-load aeration tank, a two-stage nitrification-denitrification tank, a concentration tank, a secondary sedimentation tank and a biological coagulation reaction tank.

The hydrolysis acidification tank comprises a first controller, a mechanical stirring device, a pH sensor and a temperature sensor which are arranged in the tank, a neutralization liquid tank connected with the tank through a water pump, and a first liquid inlet system arranged at the top of the tank; the side wall of the tank body is provided with an acidizing fluid sampling port, the top of the tank body is provided with an exhaust port, and the bottom of the tank body is provided with a slag discharge port; the first controller is connected with the mechanical stirring device, the pH sensor, the temperature sensor and the neutralization liquid tank;

the methane production tank comprises a second controller, a mechanical stirring device, a pH sensor and a temperature sensor which are arranged in the tank, and a second liquid inlet system arranged at the top of the tank; the second controller is connected with the mechanical stirring device, the pH sensor and the temperature sensor; the side wall of the tank body is provided with a digestive juice sampling port and a discharge port, the discharge port of the methane production tank is respectively connected with a horizontal screw centrifuge and a return pipe communicated with the methane production tank through a pipeline with a flow dividing part, the bottom of the methane production tank is provided with a slag discharge port, the top of the methane production tank is provided with a methane gas outlet, and the methane gas outlet is sequentially connected with a desulfurization and dehydration device and a methane tank;

and a communicating pipeline is arranged between the exhaust port of the hydrolysis acidification tank and the methane production pipe, and the acidification discharge port of the hydrolysis acidification tank is connected with the methane production tank through a metering pump and a circulating pipe.

Further, the system also comprises a biogas residue crusher, a second dryer and a granulator which are connected in sequence; the horizontal screw centrifuge is provided with a biogas slurry outlet and a biogas residue outlet, the biogas slurry outlet is connected with the inlet of the adjusting tank, and the biogas residue outlet is connected with the inlet of the biogas residue crusher.

The pre-dehydration device is a variable-diameter spiral liquid removal machine, the 2 theta value of the spiral cone angle is 5-8 degrees, an infrared heating device is arranged in the device, and a pressure adjusting device is arranged at an outlet.

Preferably:

(1) the pressure adjusting device is arranged at the outlet of the pre-dehydration device or the machine head with a smaller outlet is arranged, and the pressure build-up of the flow field in the machine barrel is realized by improving the blocking effect at the outlet.

(2) In the pre-dewatering device, the spiral cone angle is enlarged to 5-8 degrees, and the solid-liquid separation efficiency can be improved by increasing the spiral inner diameter cone angle to reduce the cross section of the flow channel.

(3) The pre-dehydration device is internally provided with an infrared heating device, which is beneficial to oil recovery and organic food residue hydrolysis, and oily wastewater is separated through mechanical extrusion after heating, so that the water content of garbage is reduced, the treatment efficiency of subsequent links on wet garbage is improved, the continuous and stable degradation of the wet garbage is ensured, and the quality of fermentation products can be improved.

(4) The discharge port of the methane production tank is positioned on the side wall of the methane production tank, and a valve is arranged at the discharge port of the methane production tank. The valve is connected with the solid-liquid separation device and the communicated return pipe through pipelines with flow dividing parts, 25% of digestive juice is recycled for fermentation, 75% of digestive juice enters a horizontal screw centrifuge for solid-liquid separation, the digestive juice which is not subjected to solid-liquid separation is recycled into a hydrolysis acidification tank to adjust the solid content, the discharge of the digestive juice can be reduced, the pH value of a hydrolysis acidification zone is in a range suitable for the survival of flora, the COD removal effect is better, and the methane content is higher when the recycling proportion is 25%.

(5) In the two-phase anaerobic reactor, a temperature sensor in a hydrolysis acidification tank and a temperature sensor in a methane production tank are both connected with a temperature controller to synchronously detect the temperature of materials in the tanks, heat insulation layers are arranged on the outer surfaces of the hydrolysis acidification tank and the methane production tank, a circulating hot water pipe is arranged between the heat insulation layers and a device shell and connected with the temperature controller, and the temperature controller can independently control the temperature of circulating water in the two tanks, so that the optimal reaction temperature in the hydrolysis acidification tank is kept at 35-38 ℃, and the optimal reaction temperature in the methane production tank is kept at 55-58 ℃. The hydrolysis acidification reaction is carried out under the condition of medium temperature (35-38 ℃), the methane production reaction is carried out under the condition of high temperature (55-58 ℃), the methane yield and VS removal rate in the medium temperature-high temperature system are highest, and the richness, diversity, uniformity and dominance of the bacterial community structure are also optimal.

(6) A pH sensor is arranged in the hydrolysis acidification tank, a neutralization liquid tank is arranged on the right side of the tank body and is connected with the tank body through a water pump, and CaCO is filled in the neutralization liquid tank₃The solution, the mechanical stirring device, the pH sensor and the neutralization tank are connected with a controller, and the controller is used for synchronously detecting the pH value of materials in the tank and adjusting and controlling the stirring of the materials in real time, wherein the pH value is controlled to be 6.5-7.8; the methane production tank is internally provided with a mechanical stirring device 15 and a pH sensor which are connected with a controller and used for synchronously detecting the pH value of materials in the tank and controlling the stirring of the materials, wherein the pH value is controlled to be 7.0-7.5; when the two-phase anaerobic combined reactor is used for treating wet garbage in villages and towns, hydrolytic acidification reaction is carried out under the condition that the pH value is 6.5-7.8, methane production reaction is carried out under the condition that the pH value is 7.0-7.5, acetic acid and butyric acid type fermentation is mainly carried out in a hydrolytic acidification area in the pH range, a more favorable substrate can be provided for the subsequent methane production process, the wet garbage has higher hydrolysis and acidification rates, the VFA yield is 2 times of that when the pH value is not adjusted, the methane production quantity is sensitive to the pH value, and the methane production quantity is highest when the pH value is 7.

Has the advantages that:

(1) the invention provides a reinforced two-phase anaerobic fermentation treatment system and method for village and town wet garbage, wherein garbage with different components in the wet garbage is sorted by adopting a directional sorting treatment technology according to different components in the garbage with different particle sizes, so that organic components capable of anaerobic fermentation are sorted out, the sorting efficiency and the purity of sorted substances are improved, impurities are removed, and recycled and available components are recycled.

(2) In view of the difficult biodegradability of cellulose, hemicellulose and lignin substances in the wet garbage, the cellulose, hemicellulose and lignin substances are difficult to degrade in the anaerobic fermentation process and can inhibit the anaerobic fermentation of other components; when wet garbage is sorted, cellulose-containing substances such as stems and leaves contained in the wet garbage are sorted out by a stem and leaf sorting machine, are ground properly by a machine, and are subjected to secondary fermentation or natural decomposition by a biological strain technology to form an organic fertilizer for utilization.

(3) The wet garbage has low C/N of about 10, and the straw has high C/N of about 40; according to the invention, by combining the actual conditions of villages and small towns, after the wet garbage and the corn straws are reasonably proportioned, the optimal C/N ratio can be adjusted to 15-20 on the characteristics of raw materials, so that microorganisms can obtain sufficient carbon sources and nitrogen sources, sufficient nutrient substances can be provided, the problem of insufficient nutrient components of single substances is solved, the multi-raw-material mixed fermentation has the advantages of diluting toxic compounds and enhancing the synergistic effect of microorganisms, the anaerobic conversion efficiency of organic matters is further improved, the raw materials can be obtained locally, and the transportation cost is saved.

(4) The anaerobic reaction process is decomposed into a hydrolysis acidogenesis stage and a methanogenesis stage, the two stages are separated, and two reactors are adopted, so that the mutual inhibition between microorganisms or the inhibition of metabolic products on the activity of the microorganisms in the reaction process is avoided, the fermentation efficiency is improved, and a proper growth environment is provided for acidogenic bacteria and methanogenic bacteria. The acid-producing phase and the methane-producing phase which are successfully operated are two independent processing units, can respectively optimize operation parameters, and are connected in series in a certain form, so that a complete anaerobic fermentation process is realized; because the operating parameters of the two units can be independently controlled, the effects of hydrolytic acidification and methanation can be simultaneously optimized, and the processing capacity of the system and the operating stability of the reactor are greatly improved.

(5) The reinforced two-phase anaerobic treatment system and method for the wet garbage in the villages and the towns have good treatment effect and good integration degree, and greatly improve the resource utilization rate.

Drawings

FIG. 1 is a schematic view of the reinforced two-phase anaerobic treatment method for wet garbage in villages and towns of the present invention;

FIG. 2 is a schematic view of a two-phase anaerobic enhanced village and town wet waste treatment system of the present invention;

FIG. 3 is a schematic of a two-phase anaerobic fermentation reactor of the present invention.

Wherein, 1, a hydrolysis acidification tank; 2. a feed inlet; 3. a slag discharge port; 4. an acidified liquid sampling port; 5. a mechanical stirring device; 6. a temperature sensor; a pH sensor; 8. a first liquid inlet system; 9. acidifying the discharge hole; 10. a gas delivery pipe; 11. a methane generating tank; 12. a discharge port; 13. a slag discharge port; 14. a digestive juice sampling port; 15. a mechanical stirring device; 16. a temperature sensor; a pH sensor; 18. a second liquid inlet system; 19. an activated carbon adsorption desulfurization, condensation dehydration and molecular sieve pressure swing adsorption device; 20. a gas flow meter; 21. a methane outlet; 22. a metering pump; 23. a second controller; 24. a first controller; 25. a temperature controller; 26. a neutralization liquid tank; 27. a manual sorting table; 28. a variable diameter screw liquid remover; 29. a first-stage drum screen; 30. a secondary drum sieve; 31. a magnetic separator; 32. a winnowing machine; 33. an electrostatic classifier; 34. a hammer impact crusher; 35. a stem and leaf separator; 36. a glass sorter; 37. a double-roll crusher; 38. a blending tank; 39. a first dryer; 40. a two-phase anaerobic fermentation reactor; 41. a horizontal screw centrifuge; 42. a biogas residue crusher; 43. a second dryer; 44. and (4) a granulator.

Detailed Description

The present invention will be described in further detail with reference to examples.

Example 1:

as shown in fig. 1, a schematic diagram of a method for enhancing two-phase anaerobic fermentation of wet garbage in villages and towns according to the present invention includes: wet garbage pretreatment, corn straw pretreatment, two-phase anaerobic fermentation treatment, sewage treatment and reflux treatment.

The wet garbage pretreatment process comprises the steps of manually sorting out large interfering objects such as plastics, glass and metals from wet garbage, then carrying out pre-dehydration, screening the wet garbage with the pre-dehydrated moisture content of the wet garbage, sorting the components contained in the garbage with different particle sizes by adopting a directional sorting treatment technology, sorting out the metals, plastics, fibers and inorganic substances in the wet garbage through magnetic separation, air separation and electrostatic sorting, and carrying out corresponding treatment and recovery; the primarily sorted organic garbage falls into a crushing device, and the organic garbage is crushed into particles of 20 mm; opening a discharge port of the crushing device, enabling organic garbage particles to fall into a stem and leaf sorting machine to sort plant stems and leaves, and then falling into a glass sorting machine to sort glass, so as to obtain organic garbage with high purity.

Wherein, the wet garbage pretreatment specifically comprises the following steps:

s1, the wet garbage is firstly sent to a manual sorting table, large interfering objects such as plastics, glass, metal and the like in the wet garbage are manually and primarily sorted out, and the residual wet garbage is sent to a solid-liquid separation device through a conveyor belt.

S2, enabling the wet garbage to enter a pre-dehydration device, internally arranging an infrared heating device to heat the wet garbage, enabling the heating temperature to be 45-50 ℃, setting the radiation power to be 1kW, enabling the infrared heating wet garbage to be beneficial to oil recovery and organic food residue hydrolysis, extruding and separating oily wastewater from the heated wet garbage through a spiral machine, reducing the moisture content of the garbage, improving the sorting efficiency of a subsequent screening link on the wet garbage, improving the quality of a fermentation product, discharging the garbage with the moisture content of less than or equal to 75% from a solid discharging end, enabling the oily wastewater to flow out from a liquid outlet, carrying out impurity separation through a pipeline filter, conveying the oily wastewater to an oil-water separation device, processing the oily wastewater after oil extraction to prepare industrial oil, and enabling the wastewater to enter a sewage treatment system.

S3, the pre-dehydrated garbage enters a primary drum screen to screen the garbage, the screening aperture is 40mm, the rotating speed is 15-20 r/min, the garbage particles with the particle size larger than 40mm are used as oversize materials of the primary drum screen and are discharged from a discharge port to be sent to a magnetic separator, separating the metallic garbage from the garbage under the action of magnetic force of a magnetic separator, then feeding the metallic garbage into a winnowing machine, utilizing the weight difference among components of a primary screening oversize material, winnowing, crushing the sorted medium materials (including organic components, plant stems and leaves and glass) in a hammer type impact crusher, collecting the heavier materials in a heavy garbage collecting tank, wherein the main component is inorganic matter, the garbage can be buried, lighter materials (including plastics and fibers) are subjected to electrostatic separation to separate the plastics and the fibers, and garbage particles with the particle size of less than 40mm are collected by a collecting tank as undersize materials and then enter a secondary screening process.

And S4, feeding undersize products of the first-stage drum screen into a second-stage drum screen by a belt conveyor, wherein screen holes of the second-stage drum screen are 8mm, the rotating speed is 20-22 r/min, garbage particles with the particle size larger than 8mm are discharged from a discharge hole to be sent to a hammer type impact crusher for crushing as oversize products of the second-stage drum screen, and the garbage particles with the particle size smaller than 8mm are collected by a collecting tank and then can be buried.

S5, feeding the winnowed medium materials and oversize materials of a secondary drum screen into a hammer type impact crusher, feeding garbage into the crusher from an upper feeding port, crushing the garbage by high-speed impact of a hammer, crushing the garbage into particles with the particle size smaller than 20mm, arranging a screen plate on the lower portion of a rotor of the hammer type impact crusher, enabling the screen holes on the screen plate to be uniformly distributed, enabling the size of each screen hole to be 20mm, discharging the particles smaller than the size of each screen hole in the crushed materials through the screen plate, blocking the coarse particles larger than the size of each screen hole on the screen plate, continuously beating and grinding the particles by the hammer, finally discharging the particles out of the crusher through the screen plate, and conveying the particles to a stem and leaf separator by a conveyor belt.

S6, sorting the stems and leaves in the stem and leaf sorting machine according to the characteristic that the color depth of the garbage particles and the stems and leaves contained in the garbage particles is different from the contrast of the light sensation. The garbage in the hopper is conveyed into a channel by a vibration feeder to be arranged in a single row and sequentially falls at the speed of 3.5m/s, a photoelectric detection system optically detects garbage particles through light rays refracted by a background plate under the irradiation of a fluorescent lamp, a CCD sensor detects and analyzes the garbage particles, the color of detected stem leaves is compared with the contrast color of the background, when substances with the same color as that of the stem leaves are captured, optical signals of the stem leaves are immediately converted into electric signals, a judgment processing circuit analyzes and processes the signals, a high-speed electromagnetic valve is instructed to start a high-pressure air flow nozzle, the pressure is 0.4-0.6 MPa, high-speed jet air flow blows the stem leaves into a collecting tank, a lifter lifts the stem leaves into a secondary feeding hopper to perform secondary color sorting, and the residual garbage is conveyed to a glass sorting machine through a discharge port.

S7, enabling the garbage to enter a feeder from a feed hopper and convey forwards, enabling free falling bodies of the garbage to enter a glass chute of an optical sorting machine, recording and analyzing the falling garbage by a high-resolution camera, accurately blowing the glass to a glass collecting tank by a compressed air valve according to a set program, and conveying the residual organic garbage to a batching tank.

S8, placing stem and leaf substances sorted by a stem and leaf sorting machine and fiber substances sorted by static electricity in a fermentation tank, adding a compound microbial inoculum comprising fungi, actinomycetes, saccharomycetes and a bacterial compound beneficial bacterium group into the fermentation tank, controlling the temperature to be 15-17 ℃, the pH to be 6-8 and the humidity to be 55-65%, stacking for 24h, then starting to heat up, heating to 50-70 ℃ after 48h, uniformly distributing the bacteria by using a turnover planer in an untimely manner in the process, turnover planing for heat dissipation, successfully fermenting for 8-16 d, converting the treated fiber garbage into an organic fertilizer and a soil matrix which are easy to be absorbed by soil and plants, and further processing according to the requirements of different plants, wherein the produced fertilizer can be used in multiple fields of urban greening, nursery production, breeding and cultivation.

The corn stalk pretreatment is to crush the corn stalk into particles smaller than 5mm, mix 0.5% KOH and 2% Ca (OH)₂Hermetically storing for 7 days at 38 ℃, mixing the treated corn straws and the organic garbage according to a mixing ratio of 1: 4, and adjusting the optimal C/N ratio to 15-20 on the characteristics of raw materials; adding composite bacteria composed of Trichoderma and Bacillus in a ratio of 1: 1, wherein the concentration of the bacteria liquid is 4.5 × 10⁷CFU/mL。

The corn straw pretreatment specifically comprises the following steps:

s1, pretreating corn straws, crushing the corn straws into particles smaller than 5mm by using a double-roller crusher, conveying the crushed corn straws to a blending tank for blending, and mixing 0.5% of KOH and 0.5% of KOH2% of Ca (OH)₂Sealed storage at 38 ℃ for 7d, KOH and Ca (OH)₂The combined pretreatment can effectively remove lignin in the corn straws, destroy the wood fiber structure of the corn straws, increase the accessibility of the matrix, facilitate the hydrolysis of enzyme and improve the anaerobic fermentation conversion rate.

S2, mixing the pretreated corn straws and the organic garbage according to a mixing ratio of 1: 4, adjusting the optimal C/N ratio to 15-20 on the characteristics of raw materials, adjusting the matching of acid production rate and methane production rate on the fermentation kinetics to stabilize the fermentation process, adding composite bacteria consisting of trichoderma and bacillus, wherein the bacteria quantity ratio is 1: 1, and the concentration of the bacteria liquid is 4.5 multiplied by 10⁸CFU/mL, the microbial community can degrade cellulose and lignin contained in the corn straws and the organic garbage, and the microbial community and acid-producing bacteria and methanogen have synergistic effect, so that the degradation rate of the organic garbage can be improved, the system stability is effectively improved, and the mixed material is sent to a hydrolysis acidification tank.

The two-phase anaerobic fermentation treatment is that the prepared material is put into a hydrolytic acidification zone, hydrolytic acidification reaction is carried out at the medium temperature (35-38 ℃), hydrolytic acidification bacterial liquid is pumped into a first liquid inlet pipe by a water pump and sprayed to the surface of the organic material by a first atomizing spray head, the hydrolytic acidification liquid contains a large amount of acid-producing bacteria which are mixed bacteria of clostridium, acetic acid bacteria and rat spore bacteria, the bacterial quantity ratio is 1: 1, and the concentration of the bacterial liquid is 5.5 multiplied by 10⁸CFU/mL, the acidification period is 4d, the formed hydrolysis acidification liquid enters a methanogenesis area, anaerobic fermentation reaction is carried out at high temperature (55-58 ℃), methanogenesis bacteria liquid is pumped into a second liquid inlet pipe by a water pump and sprayed to the surface of a material by a second atomization nozzle, the methanogenesis bacteria liquid contains a large amount of methanogenesis microorganisms which are mixed bacteria of methanogenesis bacillus, methanothermobacter and methanosarcina, the bacteria amount ratio is 1: 1, and the concentration of the microorganism bacteria liquid is 5.5 multiplied by 10⁸CFU/mL; in the anaerobic fermentation period of 10d, the generated biogas is sequentially subjected to activated carbon adsorption desulfurization, condensation dehydration and molecular sieve pressure swing adsorption to remove CO₂After impurities are mixed, the mixture is sent into a methane tank for storage, can be used for power generation or used as fuel for heat supply, 25 percent of digestive juice flows back to a hydrolysis acidification tank to adjust the solid content, and 75 percent of digestive juice flows outAnd (3) feeding the water overflow pipe into a horizontal screw centrifuge for solid-liquid separation to separate biogas residues and biogas slurry, crushing the biogas residues by a biogas residue crusher, drying and granulating, and feeding the biogas slurry into a sewage collection box.

The two-phase anaerobic fermentation treatment specifically comprises the following steps:

s1, stirring the materials by a mechanical stirrer in a hydrolysis acidification tank at a speed of 50r/min for 20min/h, arranging a heat-insulating layer in the tank, arranging a circulating hot water layer between the heat-insulating layer and the shell of the device, keeping the temperature of the acidification process at 35-38 ℃ by a temperature controller, and arranging CaCO in the hydrolysis acidification tank₃The neutralizing liquid tank of the solution is connected with the tank through a water pump, the pH in the tank is adjusted to be controlled to be 6.5-7.8, the hydrolysis acidification bacterial liquid is sprayed on the material through an atomizing nozzle, the hydrolysis acidification liquid contains a large amount of acid-producing bacteria which are mixed bacteria of clostridium, acetic acid bacteria and rat spore bacteria, the bacterial quantity ratio is 1: 1, and the concentration of the bacterial liquid is 5.5 multiplied by 10⁸CFU/mL, acidification period 4 d.

S2, feeding the hydrolyzed and acidified liquid into a methane tank through a feeding pipe for digestion, spraying a methane-producing bacteria liquid onto the material through an atomizing nozzle, wherein the methane-producing bacteria liquid contains a large amount of methane microorganisms which are mixed bacteria of methanobacterium, methanothermobacter and methanosarcina, the bacteria amount ratio is 1: 1, and the concentration of the microorganism bacteria liquid is 5.5 multiplied by 10⁸A CFU/mL, wherein a stirrer is also arranged in the methane production tank, the rotating speed of the stirrer is 50r/min, the stirring time is controlled to be 20min/h, the pH value is controlled to be 7.0-7.5, a heat insulation layer is arranged in the tank, a circulating hot water layer is arranged between the heat insulation layer and the shell of the device, the temperature is controlled to be 55-58 ℃, and the digestion period is 10 d;

s3, refluxing 25% of digestion liquid in a methane production area to a hydrolysis acidification tank to adjust the solid content, relieving the VFA inhibition effect of an acidification phase, improving the methane production performance of the methane phase, feeding 75% of digestion liquid to a horizontal screw centrifuge for solid-liquid separation through a water outlet overflow pipe, separating biogas residue and biogas slurry, crushing the biogas residue through a biogas residue crusher, drying and granulating the biogas slurry, feeding the biogas slurry to a sewage collection tank, and removing CO from the biogas through activated carbon adsorption desulfurization, condensation dehydration and molecular sieve pressure swing adsorption in turn₂After impurities are mixed, the mixture is sent into a methane tank for storageAnd (4) storing.

The sewage treatment and reflux treatment are implemented by that the treated sewage is derived from sewage separated by an oil-water separator, biogas slurry separated by a horizontal screw centrifuge, percolate of each garbage treatment unit, daily drainage of each workshop, domestic sewage and the like, the sewage is treated by adopting a coagulation air flotation-high load aeration tank-two-stage A/O-MBR process, anaerobic biogas slurry is conveyed into a regulating tank, then the anaerobic biogas slurry is pumped into a subsequent air flotation treatment unit by a water pump, a certain amount of flocculating agent and coagulant are added into the sewage before the sewage enters the air flotation unit, so that the effect of removing suspended matters and grease can be achieved, colloid and partial phosphate are removed, the effluent of the air flotation unit is pumped into a high load aeration tank, most of organic matters are removed, then the effluent of the air flotation unit enters a secondary sedimentation tank for mud-water separation, the effluent of the secondary sedimentation tank automatically flows into a two-stage nitrification-denitrification tank to remove the residual organic matters and nitrogen pollutants in the sewage, and finally, carrying out sludge-water separation by a built-in MBR (membrane bioreactor) membrane component, recycling the effluent for a two-phase anaerobic system and a straw pretreatment system to adjust the humidity, refluxing a part of sludge to the front-end first-stage denitrification tank, discharging a part of sludge as residual sludge into a concentration tank, discharging sludge in the air flotation tank and the secondary sedimentation tank into the concentration tank, concentrating the sludge, then, entering a biological coagulation reaction tank for deep dehydration, refluxing the generated clear liquid to the first-stage denitrification tank, and refluxing the generated slag cake and sludge cake to a hydrolysis system.

Example 2:

fig. 2 shows a reinforced two-phase anaerobic treatment system for wet garbage in villages and towns, which consists of a wet garbage pretreatment system, a corn straw pretreatment system, a reinforced two-phase anaerobic fermentation system and a sewage treatment and reflux system.

Wherein, wet rubbish pretreatment systems is used for sorting, screening, breakage, dehydration in advance to wet rubbish, and this system includes: the device comprises a discharge hopper, a manual sorting table 27, a pre-dewatering device, a water-oil separation device, a primary rotary screen 29, a magnetic separator 31, a winnowing machine 32, an electrostatic sorting machine 33, a secondary rotary screen 30, a hammer impact crusher 34, a stem-leaf sorting machine 35 and a glass sorting machine 36, wherein the primary rotary screen and the secondary rotary screen are respectively provided with an oversize material discharge port and an undersize material discharge port, the magnetic separator is provided with a magnetic material discharge port and a non-magnetic material discharge port, and the winnowing machine is provided with a light material discharge port, a medium material discharge port and a primary heavy material discharge port.

The device comprises a manual sorting table, a pre-dewatering device, a first-stage rotary screen, a second-stage rotary screen, a hammer type impact crusher, a stem and leaf sorting machine and a glass sorting machine which are sequentially connected, wherein a screen underflow discharge port of the first-stage rotary screen is connected with a feed port of the second-stage rotary screen, a screen overflow discharge port of the first-stage rotary screen is connected with a feed port of a magnetic separator, a nonmagnetic material discharge port of the magnetic separator is connected with a feed port of a winnowing machine, a medium material discharge port of the winnowing machine and a screen overflow discharge port of the second-stage rotary screen are both connected with a feed port of the hammer type impact crusher, and a light material discharge port of the winnowing machine is connected with a feed port of an electrostatic sorting machine.

The manual sorting table 27 is composed of plate chain conveyors, the width of the frame is 1.3m, the moving speed of a belt is not more than 0.3m/s, a feeding hole and a discharging hole are formed in the manual sorting table, wet garbage enters the manual sorting table through the feeding hole, rubber, metal, glass and the like in the garbage are sorted out through manual sorting, the rest wet garbage is conveyed out through the discharging hole, a conveying belt is arranged on the lower portion of the discharging hole, and the conveying belt can convey the wet garbage to a solid-liquid separation device.

The pre-dehydration device is a variable diameter screw liquid removing machine 28 which mainly comprises a variable diameter screw, a motor, a filter cylinder and a machine head, wherein the device is provided with a feed inlet, a discharge outlet and a liquid outlet, an infrared heating device is arranged in the device, the heating temperature is 50 ℃, the radiation power is set to be 1kW, wet garbage is added into a hopper from the feed inlet, the motor drives the screw to rotate, materials are conveyed forwards under the combined action of the screw, the filter cylinder and the machine head, the extrusion liquid removal is realized, the rotating speed of the screw is 20rpm, the pre-dehydrated garbage is discharged from the discharge outlet and falls into a conveying belt to be conveyed to a No. 1 rotary screen, namely a first-stage rotary screen 29, and oil-containing wastewater is conveyed into an oil-water separator from the liquid outlet to be subjected to oil-water separation.

The barrel of No. 1 drum sieve is the slope and places, and the barrel is covered by dust-proof sealing cover, and the high-end feed inlet that is equipped with of slope cylinder, slope cylinder low side are equipped with oversize thing discharge gate, are equipped with the speed reducer in the section of thick bamboo, and it is rotatory with certain rotational speed to adjust the barrel, and the cylinder rotational speed is 15 ~ 20r/min, and slope cylinder lower part is equipped with undersize thing collecting vat, and the last sieve hole evenly distributed of slope cylinder stack shell, the sieve mesh diameter is 40mm, and cylinder inclination is 7 ~ 10, and wet rubbish is after the drum screening, and oversize thing is delivered to the magnet separator by the conveyer belt that sets up in oversize thing discharge gate lower part, and undersize thing is collected and is delivered to No. 2 drum sieve 30 by undersize thing collecting vat, second grade drum sieve promptly.

The magnetic separator 31 is a cylindrical magnetic separator and consists of a rotary multi-pole magnetic system and an external non-magnetic-conductive cylinder, a garbage feeding port is arranged at the upper part of the machine body, a metal collecting box is arranged at the lower left part, a garbage discharging port is arranged at the lower right part, and the discharging port is connected with a garbage collecting tank; when wet garbage passes through the cylindrical magnetic separator, under the combined action of magnetic force and mechanical force, metal is adsorbed on the belt and falls into the metal collection box, the wet garbage after the metal is removed enters the collection tank, a conveying belt is arranged below the collection tank, and the conveying belt is connected with the winnowing machine.

The winnowing machine 32 comprises a frame, a conveying belt rotatably connected to the upper end of the frame, a feeding hole positioned at the lower end of the conveying belt, an air suction pipeline positioned at the high end of the conveying belt, and a fan positioned on the air suction pipeline, wherein a heavy garbage collecting tank is arranged on the right side of the air blower, and a light garbage collecting tank is arranged on the right side of the heavy garbage collecting tank. Wet garbage is conveyed into a feeding hole through a conveying belt, heavier materials fall into a heavy garbage collecting tank, and the heavy garbage collecting tank can be buried as the main component of inorganic matters; the lighter material falls into a light garbage collection tank, such as plastic, fiber, etc. The air speed of the air blower is 1.6-2.1 m/s.

The drum body of the No. 2 drum screen is obliquely placed, the drum body is covered by a dustproof sealing cover, a feed inlet is formed in the high end of the inclined drum, an oversize material discharge port is formed in the low end of the inclined drum, a speed reducer is arranged in the drum, the drum body is adjusted to rotate at a certain rotating speed, an undersize material collecting tank is formed in the lower portion of the inclined drum, screen holes in the drum body of the inclined drum are uniformly distributed, the diameter of each screen hole is 8mm, the rotating speed of the drum is 20-22 r/min, and the inclination angle of the drum is 7-10 degrees; after undersize of the No. 1 drum screen is screened by a drum, oversize and garbage winnowed from the winnowing machine enter a hammer type impact crusher together; the undersize is collected by an undersize collecting tank and can be landfilled.

The hammer impact crusher 34 consists of a hammer, a rotating shaft, a disc, a bearing, an impact plate, a sieve plate and the like, wherein the hammer is movably hinged on a rotating disc of a rotor, the rotating shaft and the rotating disc are supported on rolling bearing seats at two sides of a shell, and a motor drives the rotor to rotate at a high speed in a crushing cavity. The material is in the feeder inlet machine from upper portion feed inlet, receive the high-speed impact of hammer and breakage, it is less than 20mm to break into the particle diameter with rubbish, hammer counterattack breaker is in the rotor lower part, be equipped with the sieve, sieve mesh evenly distributed on the sieve, sieve mesh size 20mm, the particle fraction that is less than sieve mesh size in the crushing material is discharged through the sieve, the coarse grain fraction that is greater than sieve mesh size keeps continuing to receive the strike and the grinding of hammer on the sieve, outside through the sieve discharge machine at last, send to glass-sorting machine by the conveyer belt.

The stem leaf sorting machine 35 is a photoelectric color sorting machine mainly composed of a CCD sensor, a high-speed magnetic valve, a nozzle, a discharging mechanism and the like, firstly, garbage in a hopper is sent into a channel by a vibration feeder to be arranged in a single row and fall at the speed of 3.5m/s in sequence, a photoelectric detection system optically detects garbage particles by light rays refracted by a background plate under the irradiation of a fluorescent lamp, the garbage particles are detected and analyzed by the CCD sensor, the color of detected stem leaves is compared with the contrast color of the background, when substances with the same color as the stem leaves are captured, optical signals are immediately converted into electric signals, then after the signals are analyzed and processed by a judgment processing circuit, pulsed compressed air sprayed out by the high-speed electromagnetic valve control nozzle blows the stem leaves away from a normal moving track, falls into a collecting tank and is lifted into a secondary feeding hopper by a lifter to perform secondary color sorting, and the residual garbage is conveyed to the glass sorting machine from a discharge port. The photoelectric color selector is provided with a material returning device such as a lifter, can automatically reselect stem leaves with low precision after primary color selection, equivalently two primary color selectors perform two-stage color selection simultaneously, can sort out plant stem leaves in wet garbage to the maximum extent, saves manpower, material resources and time, and is favorable for improving the color selection precision.

The glass sorting machine 36 adopts an optical sorting machine and comprises a feed hopper, a feeding machine, a glass chute, a high-resolution camera and a compressed air valve, the garbage enters the feeding machine from the feed hopper and is conveyed forwards, the free falling body of the garbage enters the glass chute of the optical sorting machine, the falling garbage is recorded and analyzed by the high-resolution camera, the compressed air valve accurately blows the glass to a glass collecting tank according to a set program, and the residual garbage is conveyed to a batching tank through a conveying belt.

Corn stalk pretreatment system for with corn stalk pretreatment, get rid of matters such as lignin, cellulose, hemicellulose that wherein contains, reach the optimum state with organic rubbish mixed anaerobic fermentation, this system includes: a double-roller crusher 37, a blending tank 38 and a first dryer 39. Two rollers are arranged inside the double-roller crusher, the surfaces of the two rollers are both in a sawtooth shape, the two rollers rotate to crush corn straws, the corn straws are crushed into particles with the particle diameter smaller than 5mm, the double-roller crusher is arranged on the lower portion of the rollers and is provided with a sieve plate, sieve holes on the sieve plate are uniformly distributed, the size of the sieve holes is 5mm, the particles smaller than the size of the sieve holes in the crushed corn straws are discharged through the sieve plate, the coarse particles larger than the size of the sieve holes are retained on the sieve plate to continue crushing, a feeding port is arranged above the double-roller crusher, a discharging port is arranged at the bottom of the double-roller crusher, and the crushed corn straws are sent to a blending tank through a conveying belt arranged on the lower portion of the discharging port. The blending tank is provided with a feeding hole, a discharging hole and a liquid inlet, a mechanical stirring device, a heating device and a temperature sensor are arranged inside the blending tank, corn straws enter the tank through the feeding hole, KOH enters the tank through the liquid inlet, the KOH is fully stirred through the stirring device, the temperature is controlled at 38 ℃, the blending tank is sealed for 7d, and the dried corn straws are sent to the hydrolysis acidification tank through the first dryer 39.

The reinforced two-phase anaerobic fermentation system is used for combining the pretreated corn straws and garbage for two-phase anaerobic fermentation, and comprises: a two-phase anaerobic fermentation reactor 40, a horizontal screw centrifuge 41, a biogas residue crusher 42, a second dryer 40, a granulator 44, a biogas storage tank and a sewage collection box.

As shown in figure 3, the two-phase anaerobic fermentation reactor is divided into a hydrolysis acidification tank 1 and a methanogenesis tank 11. The hydrolysis acidification tank 1 is provided with a feed inlet 2 and a discharge outlet 9, a mechanical stirring device 5, a pH sensor 7 and a neutralization liquid tank 26 are arranged on the right side of the tank body in the hydrolysis acidification tank, the neutralization liquid tank is connected with the tank body through a water pump, CaCO is filled in the neutralization liquid tank₃Solution, mechanical stirring device 5, pH sensor 7 and neutralization solution tank 26The device is connected with a first controller 24 and used for synchronously detecting the pH value of materials in the tank and adjusting and controlling the stirring of the materials in real time, the pH value is controlled to be 6.5-7.8, a first liquid inlet system 8 is installed at the top of the hydrolysis acidification tank and comprises a first liquid inlet pipe and a first atomization nozzle, the first atomization nozzle is uniformly distributed on the first liquid inlet pipe, the first liquid inlet pipe is connected with a hydrolysis acidification liquid storage tank through a water pump, a large amount of acid-producing bacteria such as clostridium, acetobacter, mouse spore and the like are contained in the hydrolysis acidification liquid, an acidification discharge port 9 is connected with a methane production tank 11 through a metering pump 22 and a circulating pipe and used for conveying the acidification liquid, a gas conveying pipe 10 is arranged between the hydrolysis acidification tank 1 and the methane production tank 11, an acidification liquid sampling port 4 is arranged on the side wall of the hydrolysis acidification tank, a slag discharge port 3 is arranged at the bottom of the hydrolysis acidification tank, a temperature sensor 6 is arranged in the hydrolysis acidification tank, and is connected with a temperature controller 25, the material temperature in the tank is synchronously detected, the outer surface of the hydrolysis acidification tank is provided with a heat insulation layer, a circulating hot water pipe is arranged between the heat insulation layer and the device shell, the circulating hot water pipe is connected with a temperature controller 25, and the temperature controller controls the temperature of the circulating water to maintain the optimal reaction temperature in the tank to be 35-38 ℃.

A mechanical stirring device 15 and a pH sensor 17 are arranged in a tank of a methane production tank 11, the two are connected with a second controller 23 and used for synchronously detecting the pH value of materials in the tank and controlling the stirring of the materials, the pH is controlled to be 7.0-7.5, a second liquid inlet system 18 is arranged at the top of the methane production tank and comprises a second liquid inlet pipe and a second atomizing spray head, the second atomizing spray head is uniformly distributed on the second liquid inlet pipe, the second liquid inlet pipe is connected with a methane production bacteria liquid storage tank through a water pump, a large amount of methane production microorganisms, such as methanobacterium, methanothermobacter, methanosarcina and the like, are inoculated in the methane production bacteria liquid, a digestive juice sampling port 14 is arranged on the side wall of the methane production tank, a residue discharge port 13 is arranged at the bottom of the methane production tank, a temperature sensor 16 is arranged in the methane production tank and is connected with a temperature controller 25, the temperature of the materials in the tank is synchronously detected, a heat preservation layer is arranged on the outer surface of the methane production tank, a circulating hot water pipe is arranged between the heat preservation layer and the device shell, the circulating hot water pipe is connected with a temperature controller 25, the temperature controller controls the temperature of circulating water, the optimal reaction temperature in the tank is kept at 55-58 ℃, a valve is arranged at a discharge port 12 of the methane production tank, the valve is connected with a horizontal screw centrifuge and a return pipe communicated with the methane production tank 11 through a pipeline with a flow dividing part, 25% of digestive juice flows back to a hydrolysis acidification tank through the return pipe to adjust the solid content, 75% of digestive juice is sent to the horizontal screw centrifuge through a pipeline to be subjected to solid-liquid separation, a methane gas outlet 21 is arranged at the top of the methane production tank, the methane gas outlet 21 is communicated with an activated carbon adsorption desulfurization-condensation dehydration-molecular sieve pressure swing adsorption device 19 and a gas flowmeter 20, and the purified methane is sent to a methane tank to be stored.

The biogas residues are crushed by a biogas residue crusher 42, dried and granulated, and the biogas residues are sequentially sent into the biogas residue crusher 42, a second dryer 43 and a granulator 44.

A horizontal screw centrifuge 41 mainly composed of a rotary drum, a screw conveyor, a differential mechanism, a transmission component and the like; the biogas residue crusher is provided with a feed inlet, a discharge outlet and a liquid outlet, the materials are extruded and dewatered in the machine, and the biogas residue after solid-liquid separation is discharged from the discharge outlet and sent to the biogas residue crusher.

The biogas residue crusher 42 mainly comprises a frame, a rotor, a transmission part and the like; the frame part is formed by welding a carbon steel plate and channel steel; the rotor part adopts double-layer blades for crushing, materials enter a crushing chamber from a feeding hole, and are continuously ground by the double-layer blades, so that the materials meet the granulation requirement. The transmission part adopts belt transmission, and the belt pulley and the belt are driven by the motor and are directly transmitted to the main shaft, so that the main shaft rotates at high speed to achieve the crushing effect; and feeding the crushed biogas residues into a second dryer.

A second dryer 43 mainly composed of a heat source, a rotary drum, a draught fan, etc.; the second dryer is provided with a feeding hole and a discharge valve, and after the biogas residues enter the second dryer from the feeding hole, the biogas residues are fully contacted with hot air under the turning of the shoveling plate, so that the drying heat transfer and mass transfer speeds are accelerated; discharging the dried biogas residues to a granulator through a discharge valve.

The granulator 44 is a disc granulator, the disc angle of the granulating disc adopts an integral circular arc structure, and the granulation rate can reach more than 94%; the bottom of the granulating pan is reinforced by a plurality of radiation steel plates, so that the granulating pan is firm, durable and not easy to deform; the granulation disc is provided with a discharge port, the fertilizer with the grain size of 3-5 mm is discharged from the discharge port, and the fertilizer is cooled and then metered and packaged to form the high-quality fertilizer, so that the fertilizer is convenient to store and use.

The sewage treatment and reflux system adopts a coagulation air flotation-high load aeration tank-two-stage A/O-MBR process to treat sewage from sewage separated by an oil-water separator, biogas slurry separated by a horizontal screw centrifuge, leachate of each garbage treatment unit, daily drainage of each workshop, domestic sewage and the like, and comprises an adjusting tank, an air flotation tank, a high load aeration tank, a secondary sedimentation tank, a two-stage nitrification-denitrification tank, an MBR reaction tank, a concentration tank, a biological coagulation reaction tank, a slag removal machine and the like. Conveying the sewage into a regulating tank, pumping the sewage into a subsequent air floatation treatment unit through a water pump, adding a certain amount of flocculant and coagulant into the sewage before the sewage enters the air floatation unit, removing suspended matters and grease, removing colloid and partial phosphate, pumping the effluent of the air floatation unit into a high-load aeration tank, removing most organic matters, then feeding the effluent into a secondary sedimentation tank for sludge-water separation, feeding the effluent of the secondary sedimentation tank into a two-stage nitrification-denitrification tank automatically to remove the residual organic matters and nitrogen pollutants in the sewage, finally performing sludge-water separation through a built-in MBR, returning the effluent to a two-phase anaerobic system and a straw pretreatment system for regulating humidity, returning a part of the sludge to a front-end primary denitrification tank, discharging a part of the sludge into a concentration tank as residual sludge, discharging the sludge in the air floatation tank and the secondary sedimentation tank into the concentration tank, and feeding the sludge into a biological coagulation reaction tank for deep dehydration after the sludge is concentrated, the generated clear liquid flows back to the first-stage denitrification tank for treatment, and the generated slag cake and sludge cake return to the anaerobic fermentation system.

Claims

1. A two-phase anaerobic treatment method for reinforcing wet garbage in villages and towns is characterized by comprising the following steps: comprises wet garbage pretreatment, straw pretreatment and two-phase anaerobic fermentation treatment;

the wet waste pretreatment comprises: manually sorting and removing interferents in the wet garbage, then carrying out solid-liquid separation treatment to obtain pre-dewatered garbage, screening the pre-dewatered garbage, then carrying out directional sorting treatment according to components contained in the garbage with different particle sizes, and removing metals, plastics, fibers and inorganic matters to obtain sorted organic garbage; crushing the organic garbage to obtain a crushed material, then carrying out sorting treatment on stems and leaves and glass, and crushing the sorted organic components, plant stems and leaves and glass to obtain high-purity organic garbage with cellulose-containing substances and glass removed from the stems and leaves; placing stem and leaf substances separated by a stem and leaf separator and fiber substances separated by static electricity in a fermentation tank, and adding a composite microbial inoculum into the fermentation tank;

wherein the wet waste pretreatment comprises the following steps:

(1) manually sorting and removing interferents in the wet garbage, wherein the interferents comprise plastics, glass and metal;

(4) performing secondary screening treatment on the primary screening undersize products obtained in the step (3) to obtain undersize products with the particle size smaller than 8mm and oversize products with the particle size larger than 8mm, and collecting the undersize products and then performing landfill treatment;

(5) crushing the medium material obtained in the step (2) and the secondary screening oversize material obtained in the step (3) to obtain a crushed material with the particle size of less than 20mm, and carrying out separation treatment on stems and leaves and glass on the crushed material to obtain residual organic garbage without the stems and leaves containing cellulose substances and glass;

the straw pretreatment comprises the following steps: crushing the straws to obtain crushed substances with the particle size less than 5mm, blending the crushed substances to remove lignin substances, and then drying to obtain pretreated straws, wherein KOH and Ca (OH) are adopted in blending treatment₂Performing combined pretreatment; the VS ratio of the mixture of the pretreated straws and the organic garbage is 1: 3-5;

the two-phase anaerobic fermentation treatment comprises the following steps: mixing the pretreated straws with the organic garbage obtained by the wet garbage pretreatment, and adding a compound bacterial liquid to obtain a mixed material, wherein the compound bacterial liquid comprises trichoderma and bacillus, and the bacterial quantity ratio of the trichoderma to the bacillus is 1: 1, the concentration of the bacterial liquid is 4.5X 10⁸CFU/mL; sending the mixed material to a hydrolysis acidification area, and adding hydrolysis acidification bacteria to perform hydrolysis acidification reaction; the hydrolytic acidification liquid formed by the hydrolytic acidification reaction enters a methanogenic area, and methanogenic bacteria liquid is added for anaerobic fermentation reaction; directly refluxing a part of digestive juice of anaerobic fermentation reaction in the methanogenesis area to a hydrolysis acidification area for fermentation, wherein the refluxed part accounts for 20-30% of the total volume of the digestive juice; and carrying out solid-liquid separation treatment on the residual digestive juice to separate biogas residues and biogas slurry, drying and granulating the crushed biogas residues, and carrying out sewage treatment on the biogas slurry.

2. The method for enhanced two-phase anaerobic treatment of wet garbage in villages and towns according to claim 1, wherein: in the two-phase anaerobic fermentation treatment process; the temperature of the hydrolysis acidification reaction is 35-38 ℃, and the pH value is 6.5-7.8; the temperature of the anaerobic fermentation reaction is 55-58 ℃, and the pH value is 7.0-7.5.

3. The method for enhanced two-phase anaerobic treatment of wet garbage in villages and towns according to claim 1, wherein: the method also comprises sewage treatment, wherein the treated sewage is sewage subjected to oil-water separation treatment, biogas slurry subjected to centrifugal treatment and separation and sewage of each garbage treatment unit; the sewage is treated by adopting a coagulation air flotation-high load aeration tank-two-stage A/O-MBR process, the effluent is reused for a two-phase anaerobic fermentation system and a straw pretreatment system to adjust the humidity, one part of sludge flows back to a front-end first-stage denitrification tank, after the residual sludge is subjected to concentration treatment and deep dehydration, the generated clear liquid flows back to the first-stage denitrification tank, and the generated slag cake and sludge cake flow back to be hydrolyzed.

4. A two-phase anaerobic treatment system is reinforceed to wet rubbish in villages and small towns which characterized in that: comprises a wet garbage pretreatment system, a straw pretreatment system, a two-phase anaerobic fermentation system and a sewage treatment and reflux system;

the wet garbage pretreatment system comprises a sorting table, a pre-dehydration device, a primary drum sieve, a secondary drum sieve, a hammer type impact crusher, a stem and leaf separator and a glass separator which are sequentially connected, wherein a screen underflow discharge port of the primary drum sieve is connected with a feed port of the secondary drum sieve, a screen overflow discharge port of the primary drum sieve is connected with a feed port of a magnetic separator, a nonmagnetic material discharge port of the magnetic separator is connected with a feed port of a winnower, a medium material discharge port of the winnower and a screen overflow discharge port of the secondary drum sieve are both connected with a feed port of the hammer type impact crusher, and a light material discharge port of the winnower is connected with a feed port of the electrostatic separator; the pre-dehydration device is a variable-diameter spiral liquid removal machine, the 2 theta value of the spiral cone angle is 5-8 degrees, an infrared heating device is arranged in the device, and a pressure adjusting device is arranged at an outlet;

5. The two-phase anaerobic treatment system for enhancing wet garbage in villages and towns as claimed in claim 4, wherein:

the hydrolysis acidification tank comprises a first controller, a mechanical stirring device, a pH sensor and a temperature sensor which are arranged in the tank, a neutralization liquid tank connected with the tank body through a water pump, and a first liquid inlet system arranged at the top of the tank; the side wall of the tank body is provided with an acidizing fluid sampling port, the top of the tank body is provided with an exhaust port, and the bottom of the tank body is provided with a slag discharge port; the first controller is connected with the mechanical stirring device, the pH sensor, the temperature sensor and the neutralization liquid tank;

a communicating pipeline is arranged between an exhaust port of the hydrolysis acidification tank and the methane production pipe, and an acidification discharge port of the hydrolysis acidification tank is connected with the methane production tank through a metering pump and a circulating pipe.

6. The two-phase anaerobic treatment system for enhancing wet garbage in villages and towns as claimed in claim 4, wherein: the biogas residue crusher, the second dryer and the granulator are sequentially connected;

the horizontal screw centrifuge is provided with a biogas slurry outlet and a biogas residue outlet, the biogas slurry outlet is connected with the inlet of the adjusting tank, and the biogas residue outlet is connected with the inlet of the biogas residue crusher.