How to treat aquaculture sewage? What equipment is available?

Main treatment technologies of aquaculture wastewater

1 naturopathy

Self-purification principle of sewage by nature (natural water body, soil, etc.). ) is used to play a role. Comprises a land treatment system and an aquatic plant treatment system. Common methods include biological pond, soil treatment and constructed wetland treatment. Natural treatment method has the advantages of low investment and operating cost, and is quite economical under the condition of sufficient land, which is more suitable for wastewater treatment in small farms.

2 artificial anaerobic treatment method

Anaerobic treatment is characterized by small floor space, low energy demand and biogas production. The treatment process does not need oxygen, and has high organic matter loading potential, which can degrade some parts that aerobic microorganisms cannot degrade. After anaerobic treatment, sewage can be returned to the field as liquid organic fertilizer if there is available land, but the discharge is often large, which is not convenient for transportation and application. Generally, it is appropriate to discharge after multi-stage aerobic treatment.

3 artificial aerobic treatment method

The basic principle of aerobic treatment is that microorganisms decompose organic matter and synthesize their own cells (activated sludge) under aerobic conditions, and biodegradable organic matter can eventually be completely oxidized into simple inorganic matter. Include activated sludge method, contact oxidation method and biological rotary table method. Oxidation ditch, sbr and a/o belong to improved activated sludge process. Generally, the first-stage aerobic process cannot treat pig farm sewage, so it is necessary to treat pig farm sewage in series, such as acidification and three-stage contact oxidation process.

4 Anaerobic-aerobic treatment method

Pig farm wastewater is a kind of refractory organic wastewater with large discharge, low temperature, solid-liquid mixing, high organic matter content, rich nitrogen and phosphorus content and difficult to remove, and it is difficult to meet the discharge requirements simply by physical, chemical or biological methods. The bod (biochemical oxygen demand) load of anaerobic method is large, and the bod load of aerobic method is small. In the process of anaerobic treatment of sewage, the treated water still has a certain odor, and various indicators may not meet the national discharge standards. Generally speaking, it is necessary to adopt the process of combining various treatment methods and further aerobic treatment (oxidation pond, etc.). ) is often used as the secondary purification of anaerobic treatment. This is also a good method to treat high-concentration organic sewage at present, and it is also large-scale. After treatment, the sewage can basically meet the national discharge standards, but in the end it is generally discharged into fish ponds. On the one hand, fish ponds can further oxidize ponds and reduce the pollution of nitrogen and phosphorus to the environment.

Air flotation machine, integrated sewage treatment equipment and filter are recommended for the equipment, which can meet the discharge standards after treatment.