Slaughterhouse wastewater is common in food industry, especially in meat products and seafood industry, which is a typical industrial wastewater with industrial characteristics. In the process of meat processing, due to the special requirements of health, the production process will produce a lot of slaughter wastewater. These wastewater have the characteristics of great change in concentration and high content of organic matter, which will seriously pollute the water body if directly discharged into the environment.

Generally, slaughtering wastewater comes from slaughtering workshop, mainly including: ①washing livestock before slaughtering; ②scalding and carcass cleaning wastewater; ③ visceral cleaning wastewater; ④washing workshop floor and appliance wastewater; ⑤washing fence wastewater, etc.

The water quality has the following characteristics: ①slaughterhouse wastewater is generally reddish brown, with a bad smell, which contains a lot of blood, oil, hair, meat, bone, visceral debris, undigested food, feces and other pollutants, with high content of solid suspended solids.②Slaughterhouse wastewater has high content of organic matter and good biodegradability. High concentration organic matter is not easy to degrade and is difficult to treat. The nutrients in slaughterhouse wastewater are mainly nitrogen and phosphorus. Nitrogen mainly exists in the form of organic matter or ammonium salt, while phosphorus mainly exists in the form of phosphate. ③It contains Escherichia coli, fecal streptococcus and other pathogenic bacteria which are harmful to human health. ④The water quality and quantity change greatly in one day.

Slaughterhouse wastewater has good biodegradability. Although the pollutant index is high, after the solid impurities are removed by pretreatment processes such as coagulation sedimentation and air flotation, the biochemical treatment can generally reach the discharge standard. Cationic polyacrylamide is used in the treatment of biochemical sludge, in which the flocculant with high ionic degree and molecular weight is generally selected.