Application of cationic polyacrylamide in slaughterhouse wastewater treatment

The application of polyacrylamide is very wide, today is mainly about slaughterhouse wastewater treatment should choose what type of polyacrylamide.

Slaughter wastewater is the most common industrial wastewater in food processing industry, especially in meat and seafood processing industry, which is a typical industrial wastewater with industrial characteristics. In today's society, meat food consumption is huge. Take pork as an example. In 2008, the per capita amount of pork in China reached 54 kg, and each urban resident evenly consumes 2 kg of slaughtering wastewater from pork every month. Meat food processing industry as the upstream of the supply chain, production and processing capacity is huge. Due to the special requirements of hygiene in the process of meat processing, a large amount of slaughtering wastewater will be produced in the production process. The wastewater has the characteristics of large variation in concentration and high organic content, which will severely pollute the water body when discharged directly into the environment.

General slaughtering wastewater comes from slaughtering workshop, mainly including:

(1) Waste water scoured before slaughter;

② Scalding and cleaning the carcass wastewater;

③ Cleaning visceral wastewater;

④ Scour the workshop floor and appliance waste water;

⑤ Scour column waste water, etc.

The water quality has the following characteristics:

(1) Slaughtering wastewater is generally reddish brown and has an unpleasant smell. It contains a large amount of blood, grease, hair, meat scraps, bone scraps, visceral debris, undigested food, feces and other dirt, and has a high content of solid suspended solids.

② Slaughter wastewater has high organic content and good biochemical properties. High concentration of organic matter is not easy to degrade and it is difficult to treat. The nutrients in slaughter wastewater are mainly nitrogen and phosphorus, in which nitrogen mainly exists in the form of organic matter or ammonium salt, and phosphorus mainly exists in the form of phosphate.

③ Contain coliform, fecal streptococcus and other harmful bacteria to human health.

④ The water quality and quantity change greatly within a day.

Slaughtering wastewater generally has good biodegradability, although the pollutant index is high, but after removing solid impurities through pretreatment such as coagulation precipitation, air flotation and other processes, biochemical treatment can generally reach the discharge scale. In the treatment of biochemical sludge treatment section to use cationic polyacrylamide, and this sludge dewatering agent generally we choose high ionic degree and molecular weight flocculant.

Some special slaughtering wastewater, such as seafood processing wastewater and done-hide gelatin wastewater, have high salt content in addition to the above characteristics, and sometimes the salt content even exceeds the capacity of biochemical treatment. For this kind of waste water needs to be based on the detailed water quality of the experiment and then develop the design scheme, for a more real case can consider the use of physical and chemical methods such as catalytic oxidation process, low temperature distillation process, membrane separation process for treatment. In this case, anionic polyacrylamide or long and short ionic polyacrylamide can be used.