- Natural treatment
The principle of self-purification of sewage by nature (natural water, soil, etc.) is utilized. Includes land treatment systems and aquatic plant processing systems. Common methods include biological ponds, soil treatment methods, and constructed wetland treatments.
Due to the low investment and low operating cost, the natural treatment method is quite economical under the condition that sufficient land is available for use, and is more suitable for wastewater treatment in small farms.
- Artificial anaerobic treatment
Anaerobic treatment or biogas engineering has developed a variety of treatment technologies since the 1950s, mainly to develop wastewater from a series of high-load reactors based on improving sludge concentration and improving the mixing effect of wastewater and sludge.
The anaerobic treatment is characterized by low land occupation, low energy demand, biogas generation, no oxygen treatment, high organic matter loading potential, and degradation of some aerobic microorganisms that cannot be degraded.
- Artificial aerobic treatment
The basic principle of aerobic treatment is to use microorganisms to decompose organic matter under aerobic conditions and simultaneously synthesize self-cells (activated sludge). The biodegradable organic matter can be completely oxidized to simple inorganic substances, including activated sludge and contact oxidation. And biological turntables, etc.
Oxidation ditch, sbr and a/o belong to the improved activated sludge process. Generally, it is impossible to use the first-stage aerobic method to treat the pig sewage treatment standard, and it is necessary to carry out multi-stage series connection, such as acidification and tertiary contact oxidation process to treat pig farm sewage.
- Anaerobic-aerobic treatment
Pig farm wastewater is an organic wastewater that is difficult to treat because of its large displacement, low temperature, mixed solid and liquid in wastewater, high organic content, abundant nitrogen and phosphorus content, and easy to remove. It is purely using physical, chemical or biological methods. Difficult to meet emission requirements.
The anaerobic BOD (biochemical oxygen demand) load is large, and the aerobic BOD load is small. During the anaerobic treatment of sewage, the water body still has a certain odor after treatment, and the indicators do not necessarily meet the national emission standards.