Pretreatment process of livestock and poultry breeding wastewater

Abstract

The invention discloses a pretreatment process of livestock and poultry breeding wastewater. The pretreatment process comprises the following steps: 1) solid-liquid separation: carrying out solid-liquid separation on the livestock and poultry breeding wastewater to remove large-particle suspended matters; 2) magnetic coagulation sedimentation: treating the wastewater having undergone solid-liquidseparation to obtain magnetic powder-containing sludge and magnetically coagulated liquid; 3) pH value adjustment: adjusting the pH value of the magnetically coagulated liquid to 10.5-12; 4) gaseous membrane deamination: allowing ammonia nitrogen in the magnetically coagulated liquid to pass through a gaseous membrane in a gaseous form so as to allow the ammonia nitrogen to be absorbed by an ammonia absorption liquid; and 5) separation and reuse of magnetic powder: carrying out magnetic separation on the magnetic powder-containing sludge to obtain the magnetic powder and sludge. According to the invention, pollutants such as CODs, suspended solids, ammonia nitrogen, TP and the like in the wastewater can be synchronously removed, so subsequent biochemical treatment is facilitated; accordingto the pretreatment process, added chemicals are low in cost and toxicity and basically free of secondary pollution, a high-concentration ammonium salt solution is generated, resourceful treatment ofthe livestock and poultry breeding wastewater is achieved, the magnetic powder can be recycled after magnetic separation, and a sludge amount is reduced.

Description

technical field [0001] The invention relates to a pretreatment process for livestock and poultry breeding wastewater, and belongs to the technical field of wastewater pretreatment. Background technique [0002] In recent years, with the improvement of residents' living standards, the consumption demand for animal products has been rising, which has promoted the continuous development of animal husbandry. According to statistics, the total output value of the national animal husbandry industry in 2017 exceeded 3.2 trillion yuan, accounting for nearly 30% of the total agricultural output value. However, with the expansion of production scale, the pollution problem of livestock and poultry breeding industry has become increasingly prominent. The wastewater from livestock and poultry breeding has become the first agricultural non-point source pollution in my country, and it is also an important source of environmental pollution in my country. If it is not handled properly, it wi...

AI Technical Summary

Problems solved by technology

[0004] The pretreatment of livestock and poultry wastewater mostly uses coagulation sedimentation, but if only coagulation sedimentation is used for pretreatment, because the livestock wastewater contains a large amount of organic matter and suspended matter, the coagulation effect is poor, and enhanced coagulation is required

In addition, only coagulation and sedimentation cannot effectively remove ammonia nitrogen, and other technologies need to be combined to remove ammonia nitrogen later. If blowing off and other technologies are used, the treatment cost will be high, and it does not meet the national policy requirements for resource-based treatment of livestock and poultry manure; If ammonia nitrogen is directly treated by biological methods, due to the high concentration of ammonia nitrogen, it is not conducive to the growth of related bacteria, and the treatment effect is poor.

For phosphorus removal, if only biological methods are used to remove phosphorus, the effect is not good; chemical precipitation is used to remove phosphorus, and the dosage of chemicals is large, and the generated sludge needs subsequent treatment, which has a high cost; crystallization method (struvite method) for phosphorus removal, the yield of struvite is low and the cost is high

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