Livestock and poultry breeding wastewater treatment process.
With the rapid development of livestock and poultry farming, the impact of livestock and poultry breeding wastewater on the environment is becoming increasingly serious. Livestock and poultry breeding wastewater has the characteristics of high organic matter content, suspended solids, and high ammonia nitrogen content, and if not properly treated, it will cause great pollution to the surrounding environment. Therefore, the wastewater treatment process of livestock and poultry breeding is particularly important. This paper will focus on the wastewater treatment process of livestock and poultry breeding and the wastewater treatment method of farms.
1. Livestock and poultry breeding wastewater treatment process.
Livestock and poultry breeding wastewater mainly includes wastewater generated from pig farms, chicken farms and cattle farms. This wastewater contains a large amount of organic matter, ammonia nitrogen, phosphorus and other pollutants, which need to be effectively treated before it can be discharged or reused. At present, the wastewater treatment process of livestock and poultry breeding mainly includes three stages: pretreatment, biochemical treatment and post-treatment.
1.Pretreatment.
The purpose of pretreatment is to remove large particulate matter and some organic matter from the wastewater and create favorable conditions for subsequent treatment. Pretreatment methods include natural precipitation, sieving, centrifugal separation and other physical methods. In the pretreatment stage, some chemicals, such as acids, alkalis, flocculants, etc., can also be added to adjust the pH value of the wastewater and remove some organic matter.
2.Biochemical treatment.
Biochemical treatment is the core link of livestock and poultry breeding wastewater treatment, mainly using anaerobic and aerobic biological treatment technology.
1) Anaerobic biological treatment.
Anaerobic biological treatment refers to the use of anaerobic microorganisms to convert organic matter into gases such as methane and carbon dioxide under anaerobic or anoxic conditions. Anaerobic biological treatment has the advantages of low energy consumption, high organic load, and less residual sludge, and is suitable for the treatment of high-concentration organic wastewater. Commonly used anaerobic biological treatment technologies include anaerobic digesters, upflow anaerobic sludge beds (UASB), anaerobic fluidized beds, etc.
2) Aerobic biological treatment.
Aerobic biological treatment refers to the use of aerobic microorganisms to convert organic matter into carbon dioxide and water under aerobic conditions. Aerobic biological treatment has the advantages of good treatment effect, stable operation, and suitable for treating low-concentration organic wastewater. Commonly used aerobic biological treatment technologies include activated sludge method, biofilm method, aeration tank, etc.
3.Post-processing.
The purpose of post-treatment is to further remove residual pollutants from the biochemically treated wastewater, so that the wastewater can meet the discharge standards or reuse requirements. Post-treatment methods include filtration, disinfection, dephosphorization, etc. At this stage, the purification effect of wastewater can also be further improved through sedimentation, activated carbon adsorption and other technologies.
Second, the farm wastewater disposal method.
Treated livestock and poultry breeding wastewater can be disposed of in the following ways:
1.Discharge up to standard.
After the treated wastewater meets the discharge standards stipulated by the state or locality, it can be directly discharged into the natural water body. In order to achieve the discharge standard, it is necessary to select the appropriate treatment process and parameters to ensure that the treatment effect is stable and reliable.
2.Recycling.
On the premise of meeting environmental protection requirements, the treated wastewater can be recycled for cleaning, watering and other purposes of the farm. This not only reduces the amount of wastewater discharged, but also saves water resources and reduces the cost of farming.
3.Ecological engineering disposal.
Through the construction of artificial wetlands, oxidation ponds, land infiltration and other ecological projects, the wastewater is naturally purified and reused or discharged. Ecological engineering disposal has the advantages of low investment and simple operation and management, and also helps to improve the ecological environment and landscape construction.
4.Fertilizer disposal.
Livestock and poultry breeding wastewater is rich in organic matter and nutrients, and can be used as fertilizer after proper treatment. Fertilizer disposal can not only reduce the discharge of wastewater, but also provide nutrients for crops and realize resource utilization. However, it should be noted that fertilizer disposal should follow relevant standards and regulations to ensure safety and reliability.