CN111362505A

CN111362505A - Treatment process of pig farm wastewater

Info

Publication number: CN111362505A
Application number: CN202010186585.6A
Authority: CN
Inventors: 任嬿; 张峰; 徐丽亚; 陈小攀; 周梦莹; 陈晶晶; 黄瀚坤; 易佳琳; 胡雨聪
Original assignee: Zhejiang Institute of Mechanical and Electrical Engineering Co Ltd
Current assignee: Zhejiang Institute of Mechanical and Electrical Engineering Co Ltd
Priority date: 2020-03-17
Filing date: 2020-03-17
Publication date: 2020-07-03

Abstract

The invention relates to a treatment process of wastewater in a pig farm, and belongs to the technical field of wastewater treatment. The process comprises the following steps: (1) the pig raising wastewater passes through a solid-liquid separation device; (2) the effluent of the solid-liquid separation device enters an adjusting tank; (3) the effluent of the regulating tank enters a coagulating sedimentation tank; (4) the effluent of the coagulating sedimentation tank enters an anaerobic tank; (5) the effluent of the anaerobic tank enters an aerobic tank; (6) the effluent of the aerobic tank enters an FSMBR device; (7) the effluent of the FSMBR device enters a molecular membrane device; (8) and the effluent of the molecular membrane device enters a disinfection tank. According to the treatment process, the FSMBR technology of replacing the traditional MBR membrane by the inorganic flat membrane is combined with the molecular membrane treatment technology for treating the wastewater in the pig farm, so that the MBR membrane pollution problem is effectively improved, the treated wastewater effluent can be recycled, the environmental pollution caused by the discharge of the pig wastewater is reduced, the resource utilization rate is improved, and the harm to the environment is reduced.

Description

Treatment process of pig farm wastewater

Technical Field

The invention relates to a process, in particular to a process for treating wastewater in a pig farm, belonging to the technical field of wastewater treatment.

Background

With the development of industrial and agricultural industries, the breeding industry develops towards intensification and industrialization. In the breeding industry, the pig industry has a large proportion, the scale breeding proportion of live pigs is continuously increased, the wastewater discharge amount of a pig farm accounts for more than half of the total wastewater discharge amount of the livestock and poultry farm, and the problem of water pollution caused by wastewater generated in the breeding process is increasingly serious, so that the pig farm becomes a main source of rural pollution in China. The pig raising wastewater has the characteristics of large discharge amount, more suspended matters, high organic matter and ammonia nitrogen concentration, large odor, high heavy metal content and the like, and has the characteristics of complex water quality, dispersed discharge points, difficult collection and treatment and the like. The pig-raising wastewater has high pollutant concentration, wherein BOD is up to 2000-8000 mg/L, COD is up to 5000-20000 mg/L, ammonia nitrogen is up to 800-1500mg/L, and the pig-raising wastewater also has the characteristics of antibiotic and pathogen residue and the like. After pig raising wastewater which is not properly treated and is directly discharged enters the external environment, serious harm is caused to soil, water and atmospheric environment. Therefore, under the environmental background of emphasizing the green sustainable development, the active search for an economic and environment-friendly pig-raising wastewater treatment process is the key of the healthy development of the pig-raising industry.

At present, the scale pig-raising wastewater treatment modes mainly comprise three types: a returning mode, a natural processing mode and an industrialized processing mode. The industrial treatment mode is controllable in treatment capacity and effect due to artificial control of operation conditions, is more practical for wastewater treatment of pig farms, and is a pig-raising wastewater treatment mode which is generally adopted at home and abroad at present. At present, anaerobic-aerobic processes and MBR processes are the most widely used industrial treatment modes. The conventional anaerobic and aerobic process can meet the effluent COD standard, but the occupied area is large, the effluent ammonia nitrogen exceeds the standard, other water quality indexes are unstable, and the effluent cannot be recycled. The MBR method has good treatment effect and low sludge yield, but the independent treatment effect can not stably meet the discharge standard, and the traditional MBR membrane has serious pollution problem, thus leading to frequent cleaning and replacement of the membrane component and reduction of the service life. Aiming at the defects of the prior treatment technology, a more efficient and stable pig raising wastewater treatment process is sought, and the treatment process is the best way for treating the pollution of the breeding industry by carrying out reduction, harmless, resource treatment and reasonable utilization on pollutants.

The invention discloses an invention patent named as a method for treating wastewater of a pig farm in Chinese patent with publication number CN105836969A of 2016, 08 and 10. The wastewater of the pig farm is collected by a pipeline and enters a grating tank, and the wastewater after removing the dung materials enters a water quality adjusting device for dephosphorization, uniform water quality and preliminary hydrolysis acidification; anaerobic treatment: the wastewater treated by the water quality regulating device enters a methane tank for anaerobic treatment and then enters a hydrolysis acidification tank to hydrolyze insoluble organic matters into soluble organic matters; aerobic treatment: carrying out aerobic treatment on the wastewater treated by the hydrolysis acidification tank; deep treatment: and (4) the wastewater after the aerobic treatment enters an advanced degradation device, and advanced treatment is carried out by adopting aerobic granular sludge. Although the treatment method is easy to implement, the occupied area is large, the water quality index is unstable, and the effluent cannot be recycled. It also has the above-mentioned drawbacks.

Therefore, the pig farm wastewater treatment process has the advantages of reasonable process, environmental protection, energy conservation, reuse of wastewater effluent and improvement of resource utilization rate, and is particularly necessary.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides the pig farm wastewater treatment process which is reasonable in process, capable of effectively improving MBR membrane pollution, environment-friendly, energy-saving, capable of recycling wastewater effluent and improving resource utilization rate, and combines the FSMBR technology and the molecular membrane treatment technology by adopting an inorganic flat membrane to replace the traditional MBR membrane.

The technical scheme adopted by the invention for solving the problems is as follows: the

Compared with the prior art, the invention has the following advantages and effects: 1. the integral process is reasonable, the environment is protected, the energy is saved, the discharged water of the pig raising wastewater can be recycled, the environmental pollution caused by the discharge of the pig raising wastewater is reduced, the resource utilization rate is improved, and the harm to the environment is reduced; 2. the technology combines the FSMBR technology of replacing the traditional MBR membrane with the molecular membrane treatment technology to treat the pig-raising wastewater; while the pollution problem of the traditional MBR membrane is improved, the FSMBR process is used as the early-stage process of molecular membrane treatment, and can provide high-quality and stable water quality for a molecular membrane treatment system; the molecular membrane is used for advanced treatment of the pig raising wastewater, the water quality of effluent can reach COD (chemical oxygen demand) less than or equal to 50mg/L and ammonia nitrogen less than or equal to 8mg/L, the first-class A standard of GB18918 pollutant discharge Standard of municipal wastewater treatment plant is met, the molecular membrane can be used as general reuse water, and the water resource is saved while the harm to the environment is reduced; 3. the process is used for carrying out centralized collection and treatment on the sludge, and further carrying out resource utilization.

Drawings

FIG. 1 is a schematic flow diagram of a wastewater treatment process in a pig farm according to an embodiment of the present invention.

In the figure: the device comprises a solid-liquid separation device 1, an adjusting tank 2, a coagulating sedimentation tank 3, an anaerobic tank 4, an aerobic tank 5, an FSMBR device 6, a molecular membrane device 7, a disinfection tank 8 and a sludge tank 9.

Detailed Description

The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.

Examples are given.

Referring to fig. 1, the treatment process of wastewater from pig farms of this embodiment includes the following steps:

s1) the wastewater in the pig farm is collected and introduced into a solid-liquid separation device 1, and the separated solid-state pig manure residues are collected uniformly and then used as compost for utilization.

S2) introducing the wastewater passing through the solid-liquid separation device into the adjusting tank 2, fully adjusting the water quality and water quantity in the adjusting tank 2, and adjusting the pH value of the wastewater to 6.5-7.5 by using a sodium hydroxide solution as an adjusting agent.

S3) introducing the wastewater passing through the adjusting tank 2 into a coagulation sedimentation tank 3, adding aluminum sulfate serving as a flocculating agent and PAM serving as a coagulant aid into the coagulation sedimentation tank 3, controlling the adding amount of the aluminum sulfate to be about 8g/L and the adding amount of the PAM to be 0.1g/L, and introducing precipitates generated in the coagulation sedimentation process into a sludge tank 9.

S4) introducing the wastewater passing through the coagulating sedimentation tank 3 into an anaerobic tank 4, removing organic pollutants difficult to degrade in the wastewater in the anaerobic tank 4 through the metabolism of anaerobic microorganisms, controlling the temperature in the tank at 30-35 ℃, treating for 24h, pumping gas generated by anaerobic biological treatment into a methane tank for methane utilization, and discharging the generated sludge into a sludge tank.

S5) the aerobic tank 5 of the embodiment adopts a biological contact oxidation tank, wastewater passing through the anaerobic tank 4 is introduced into the biological contact oxidation tank for aerobic biochemical treatment, most organic pollutants are removed through the self-metabolism of microorganisms, a braid-type filler and an aeration system are arranged in the tank, a sludge discharge device is arranged at the bottom, and sludge generated in the aerobic biochemical treatment process is discharged to a sludge tank.

S6), introducing the wastewater passing through the biological contact oxidation pond into the FSMBR device 6, wherein the membrane component material of the FSMBR device 6 is flat ceramic membrane, and the frame material is 304 stainless steel.

S7) leading the effluent of the FSMBR device 6 into a molecular membrane device 7 for advanced treatment, wherein the molecular membrane material is tetrafluoroethylene, the molecular membrane is vertically arranged, and all flowing liquid vertically penetrates through membrane holes.

S8) introducing the effluent of the molecular film device 7 into a disinfection tank 8 for disinfection treatment, killing harmful microorganisms such as bacteria and viruses in the wastewater, and ensuring that the effluent meets the discharge standard and also meets the water quality standard of common reuse water.

S9) dehydrating and drying the sludge collected in the sludge tank 9 for reuse.

The application is used for treating 300t/d wastewater in a certain pig farm, and the test results of the water quality of inlet and outlet water of each test item are shown in the following table.

As can be seen from the table, the effluent quality meets the first-class A standard of GB18918 pollutant discharge Standard of municipal wastewater treatment plant, which shows that the wastewater treatment process of the pig farm is feasible.

And will be apparent to those skilled in the art from the foregoing description.

In addition, it should be noted that the specific embodiments described in the present specification may be different in the components, the shapes of the components, the names of the components, and the like, and the above description is only an illustration of the structure of the present invention. Equivalent or simple changes in the structure, characteristics and principles of the invention are included in the protection scope of the patent. Various modifications, additions and substitutions for the specific embodiments described may be made by those skilled in the art without departing from the scope of the invention as defined in the accompanying claims.

Claims

1. A treatment process of pig farm wastewater is characterized in that: the method comprises the following specific steps:

s1): collecting the wastewater of the pig farm, introducing the wastewater into a solid-liquid separation device (1) for solid-liquid separation;

s2): introducing the wastewater treated by the solid-liquid separation device (1) into an adjusting tank (2);

s3): the wastewater treated by the adjusting tank (2) is introduced into a coagulating sedimentation tank (3), and the precipitate is introduced into a sludge tank (9);

s4): introducing the wastewater treated by the coagulation sedimentation tank (3) into an anaerobic tank (4), and introducing sludge generated in the anaerobic treatment process into a sludge tank (9);

s5): introducing the wastewater treated by the anaerobic tank (4) into an aerobic tank (5), and introducing sludge generated in the biochemical treatment process into a sludge tank (9);

s6): introducing the wastewater treated by the aerobic tank (5) into an FSMBR device (6);

s7): effluent of the FSMBR device (6) is reserved and enters a molecular membrane device (7);

s8): the effluent of the molecular membrane device (7) is introduced into a disinfection tank (8) for disinfection treatment to kill bacteria and viruses in the wastewater, and the obtained effluent meets the corresponding standard.

2. The piggery wastewater treatment process according to claim 1, characterized in that: in step S1, the separated solid fecal residues are collected and used as compost.

3. The piggery wastewater treatment process according to claim 1, characterized in that: in the step S2, sodium hydroxide solution is added into the regulating tank (2) as a regulator: and adjusting the pH value of the wastewater to 6.5-7.5.

4. The piggery wastewater treatment process according to claim 1, characterized in that: in the step S3, aluminum sulfate is added into the coagulation sedimentation tank (3) as a flocculating agent, PAM is used as a coagulant aid, the adding amount of the aluminum sulfate is controlled at 8g/L, and the adding amount of the PAM is controlled at 0.1 g/L.

5. The piggery wastewater treatment process according to claim 1, characterized in that: in the step S4, the temperature of the anaerobic tank (4) is 30-35 ℃, the anaerobic treatment time is 24h, and the gas generated in the treatment process is pumped into a methane tank for methane utilization.

6. The piggery wastewater treatment process according to claim 1, characterized in that: in the step S5, the aerobic tank (5) adopts a biological contact oxidation tank.

7. The process for treating wastewater from a pig farm according to claim 1 or 6, characterized in that: in the step S5, a braid type filling and aeration system is arranged in the aerobic tank (5), and a sludge discharge device is arranged at the bottom.

8. The piggery wastewater treatment process according to claim 1, characterized in that: in the step S6, the membrane module of the FSMBR device (6) is made of a flat ceramic membrane, and the frame is made of 304 stainless steel.

9. The piggery wastewater treatment process according to claim 1, characterized in that: in the step S7, the molecular film material of the molecular film device (7) is tetrafluoroethylene, and the molecular film is vertically disposed.

10. The piggery wastewater treatment process according to claim 1, characterized in that: and sludge generated by treatment in the coagulating sedimentation tank (3), the anaerobic tank (4) and the aerobic tank (5) respectively enters a sludge tank (9).