CN111362505A - A process for treating pig farm wastewater - Google Patents

Abstract

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

Description

A process for treating pig farm wastewater

technical field

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

Background technique

With the development of industry and agriculture, the breeding industry is developing in the direction of intensification and industrialization. In the breeding industry, pig breeding occupies a large proportion, and the proportion of large-scale pig breeding continues to increase. The discharge of wastewater from pig farms accounts for more than half of the total discharge of wastewater from livestock and poultry farms. The wastewater generated in the breeding process pollutes water bodies. The problem of pollution has become increasingly serious and has become the main source of rural pollution in my country. Pig-raising wastewater not only discharges a huge amount, but also has pollution characteristics such as a large amount of suspended solids, high concentration of organic matter and ammonia nitrogen, strong odor and rich in certain heavy metals. The concentration of pollutants in pig-raising wastewater is high, including BOD as high as 2000-8000 mg/L, COD as high as 5000-20000 mg/L, and ammonia nitrogen as high as 800-1500 mg/L. It also has the characteristics of antibiotics and pathogen residues. The directly discharged pig waste water will cause serious harm to the soil, water and atmospheric environment after entering the external environment without proper treatment. Therefore, under the environmental background of emphasizing green and sustainable development, it is the key to the healthy development of the pig industry to actively seek an economical and environmentally friendly pig wastewater treatment process.

At present, there are three main modes of large-scale pig breeding wastewater treatment: returning to the field, natural treatment and industrial treatment. Among them, the industrial treatment mode is more practical for the wastewater treatment of pig farms because of the artificial control of operating conditions, the treatment capacity and the effect are controllable, and it is the most widely used pig wastewater treatment mode at home and abroad. At present, the most widely used industrial treatment modes are anaerobic aerobic process method and MBR method. The conventional anaerobic aerobic process method can meet the effluent COD standard, but it covers a large area, the effluent ammonia nitrogen exceeds the standard, other water quality indicators are unstable, and the effluent cannot be recycled. The MBR method has good treatment effect and low sludge output, but the effect of single treatment cannot stably meet the emission standards, and the traditional MBR membrane has serious pollution problems, resulting in frequent cleaning and replacement of membrane modules and reduced service life. In view of the deficiencies of the existing treatment technologies, seeking a more efficient and stable treatment process for pig-raising wastewater, reducing, harmless, resource-based and rational utilization of pollutants is the best way to control pollution in the breeding industry.

The publication date is August 10, 2016, and in the Chinese patent with the publication number CN105836969A, an invention patent named "a method for treating wastewater from a pig farm" is disclosed. The patented pig farm wastewater is collected through pipelines and enters the grid tank, and the wastewater after removing fecal materials enters the water quality adjustment device for phosphorus removal, uniform water quality, preliminary hydrolysis and acidification; anaerobic treatment: after the treatment by the water quality adjustment device The wastewater enters the biogas tank for anaerobic treatment, and then enters the hydrolysis and acidification tank to hydrolyze the insoluble organic matter into soluble organic matter; aerobic treatment: the wastewater treated in the hydrolysis and acidification tank undergoes aerobic treatment; advanced treatment: the wastewater after aerobic treatment Enter the deep degradation equipment, and use aerobic granular sludge for advanced treatment. Although this treatment method is easy to implement, it occupies a large area, the water quality index is unstable, and the effluent cannot be recycled. Therefore, it still has the above-mentioned defects.

Therefore, it is particularly necessary to provide a pig farm wastewater treatment process with reasonable process, environmental protection and energy saving, reusable wastewater effluent, and improved resource utilization rate.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and to provide a reasonable process, effectively improve MBR membrane pollution, environmental protection and energy saving, waste water effluent can be reused, improve resource utilization, and use inorganic flat membranes to replace traditional MBR membranes The pig farm wastewater treatment process combines the FSMBR technology with the molecular membrane treatment technology.

The technical solution adopted by the present invention to solve the above problems is: the

Compared with the prior art, the present invention has the following advantages and effects: 1. The overall process is reasonable, environmental protection and energy saving, the effluent of pig-raising wastewater can be reused, the environmental pollution caused by the discharge of pig-raising wastewater is reduced, the utilization rate of resources is improved, and the energy consumption is reduced. 2. This process combines the FSMBR technology of the inorganic flat membrane instead of the traditional MBR membrane with the molecular membrane treatment technology to treat pig wastewater; while improving the pollution problem of the traditional MBR membrane, the FSMBR process acts as a molecular The pre-process of membrane treatment can provide the molecular membrane treatment system with more high-quality and stable water supply quality; as the advanced treatment of pig wastewater, the effluent quality of molecular membrane can reach COD≤50mg/L, ammonia nitrogen≤8mg/L, which meets GB18918 " Urban Sewage Treatment Plant Pollutant Discharge Standard "Class A Standard", which can be used as general reuse water, which saves water resources while reducing harm to the environment; 3. This process collects and treats sludge centrally , further resource utilization.

Description of drawings

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

In the figure: solid-liquid separation device 1, regulating tank 2, coagulation sedimentation tank 3, anaerobic tank 4, aerobic tank 5, FSMBR device 6, molecular membrane device 7, disinfection tank 8, sludge tank 9.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and through the examples. The following examples are to explain the present invention and the present invention is not limited to the following examples.

Example.

Referring to Fig. 1, the treatment process of pig farm wastewater in the present embodiment includes the following steps:

S1) The pig farm wastewater is collected and introduced into the solid-liquid separation device 1, and the separated solid pig manure residues are collected uniformly, and subsequently used for composting.

S2) Introduce the wastewater passing through the solid-liquid separation device into the regulating tank 2, fully adjust the water quality and quantity in the regulating tank 2, and use sodium hydroxide solution as a regulator to adjust the pH value of the wastewater to be 6.5-7.5.

S3) Introduce the wastewater passing through the adjustment tank 2 into the coagulation sedimentation tank 3, add aluminum sulfate into the coagulation sedimentation tank 3 as a flocculant, and PAM as a coagulant aid. The dosage of aluminum sulfate is controlled at about 8g/L, and the PAM is added The added amount is controlled at 0.1g/L, and the sediment produced during the coagulation and sedimentation process is introduced into the sludge tank 9 .

S4) Introducing the wastewater passing through the coagulation sedimentation tank 3 into the anaerobic tank 4, and removing the refractory organic pollutants in the wastewater through the metabolism of anaerobic microorganisms in the anaerobic tank 4, the temperature in the tank is controlled at 30-35 ° C, and the treatment The time is 24h, the gas produced by the anaerobic biological treatment is pumped to the biogas tank for biogas utilization, and the produced sludge is discharged to the sludge tank.

S5) the aerobic pond 5 of the present embodiment selects the biological contact oxidation pond, the waste water passing through the anaerobic pond 4 is introduced into the biological contact oxidation pond to carry out aerobic biochemical treatment, and most of the organic pollutants are removed by the self-metabolism of the microorganisms, and the pond is provided with Braided belt packing and aeration system, with a sludge discharge device at the bottom, the sludge generated in the aerobic biochemical treatment process is discharged to the sludge tank.

S6) Introduce the wastewater passing through the biological contact oxidation tank into the FSMBR device 6, the membrane module material of the FSMBR device 6 is selected from flat ceramic diaphragm, and the frame material is selected from 304 stainless steel.

S7) The effluent of the FSMBR device 6 is introduced into the molecular membrane device 7 for advanced treatment. The molecular membrane material is selected from tetrafluoroethylene, the molecular membrane is arranged vertically, and the flowing liquid all vertically passes through the membrane pores.

S8) The effluent of the molecular membrane device 7 is introduced into the disinfection tank 8 for disinfection treatment to kill harmful microorganisms such as bacteria and viruses in the waste water, so that the effluent meets the discharge standard and also meets the water quality standard of general reuse water.

S9) The sludge collected in the sludge tank 9 is dewatered and dried before being reused.

The application is used for the treatment of 300t/d wastewater in a pig farm. The test results of the influent and effluent water quality of each test item are shown in the following table.

It can be seen from the table that the effluent quality meets the Grade A standard of GB18918 "Pollutant Discharge Standard for Urban Sewage Treatment Plants", indicating that the wastewater treatment process of the pig farm is feasible.

Through the above description, those skilled in the art have been able to implement.

In addition, it should be noted that the specific embodiments described in this specification may have different shapes and names of parts and components, and the above content described in this specification is only an illustration of the structure of the present invention. All equivalent changes or simple changes made according to the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or substitute in similar manners, as long as they do not deviate from the structure of the present invention or go beyond the scope defined by the claims, All should belong to the protection scope of the present invention.

Claims (10)

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).

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