The problem of environmental pollution control in the livestock and poultry breeding industry has always been the primary problem facing the sustainable, stable, and healthy development of the livestock industry.
To promote the transformation of the development model of animal husbandry and promote the green development of animal husbandry, the first thing is to solve the problem of sewage generated by livestock and poultry farms.
In places with weak land carrying capacity, the existence of large-scale farms will inevitably affect local environmental pollution, and the main source of pollution is the pollution of biogas slurry in manure.
Therefore, on the basis of saturated land carrying capacity, how to clear the customs and improve the utilization of water resources with the standard treatment of irrigation water, and at the same time reduce the cost of pasture water treatment, has become a key problem that needs to be overcome.
At present, large-scale dairy farms mainly adopt the blister manure process, and the biogas slurry wastewater produced has the characteristics of high organic matter, high concentration of suspended solids, rich in nitrogen and phosphorus, and high shock load.
Generally, anaerobic treatment is used first to degrade most of the organic matter in the biogas slurry, but the organic matter, nitrogen, and phosphorus concentrations, and suspended solids in the biogas slurry after degradation are still very high, and further treatment is required. Therefore, it is necessary to explore an economical and feasible solution. new technology.
In order to solve the above problems, the present invention discloses a treatment method for breeding sewage in a dairy farm, which has stable water quality and good effect and is suitable for all seasons and regions.
CSTR anaerobic fermentation system, SS multi-stage ultrafiltration system, multi-effect oxidation pond, A2O2 process, and seasonal comprehensive ecological pond.
- After the manure of the dairy farm enters the regulating tank, it is fully and uninterruptedly stirred by the submersible mixer to make the manure uniform, and at the same time keep the manure concentration TS=8~12%, and then enter the CSTR anaerobic fermentation tank.
- Under the moderate temperature of 33-35 °C, the hydraulic retention is 20 days, and the organic matter is degraded into CH4, CO2, NH3, H2S gas under anaerobic conditions, and the weather is cold season.
- The temperature of the conditioning tank is increased, and the heat source comes from the CH4 gas combustion steam produced by CSTR fermentation, which is economical and environmentally friendly, and truly achieves harmless treatment and resource utilization.
- The fermenter adopts a combination of bottom stirring and side stirring for stirring in the anaerobic process, which avoids the layered state, increases the chance of contact between materials and microorganisms, and allows the biogas slurry to fully react in the anaerobic biochemical reaction process.
- The manure after being fermented by the CSTR anaerobic fermentation system enters the system. The system is an integrated machine with two internal parts, and the two stages are seamlessly connected.
- In the first stage, solid-liquid separation is carried out by single screw extrusion. The separated dry matter enters the drying area for treatment, and the liquid enters into the second stage for ultrafiltration solid-liquid separation. An appropriate dose of polyacrylamide is added between the first stage separation and the second stage separation. The secondary separation adopts laminated extrusion separation, and the separated liquid is in a clear state.
- The use of CSTR anaerobic fermentation system not only allows the biogas slurry to fully react in the anaerobic biochemical reaction process, and the organic matter is degraded into gases such as CH4, CO2, NH3, H2S, etc., but also in cold seasons, CH4 produced by CSTR fermentation can also be used. The gas burns steam to heat up the conditioning pool, which is economical and environmentally friendly, and truly achieves harmless treatment and resource utilization.
- The SS multi-stage ultrafiltration system is used to make the separated liquid clear through two-stage separation, which is the key link for water quality compliance and cost reduction.
- The use of multi-effect oxidation ponds can effectively reduce COD, ammonia nitrogen, BOD and other indicators in the liquid, and increase convenience without subsequent treatment.
- The advanced treatment link A2O2 process is adopted, which consists of anaerobic tank A1, anoxic tank A2, aerobic tank O1, and aerobic tank O2, supplemented by physicochemical treatment before and after, which can obtain good biological wastewater treatment effect.
- Seasonal comprehensive ecological ponds are used to plant lotus roots and lotus tips according to seasonal characteristics; blackfish and catfish are also cultivated. Planting lotus roots and lotus tips has economic value and can effectively degrade the organic matter in the irrigation water after treatment, thereby reducing COD, ammonia nitrogen and other indicators.