Treatment of pig factory wastewater with polyaluminium chloride
With the development of animal husbandry, the discharge of livestock wastewater is increasing, and the negative impact on agricultural ecological environment and water environment is becoming more and more serious. Pig farm sewage is mainly a mixture of pig excreta (pig urine and part of pig manure) and pig house flushing water. Pig farm sewage has large discharge, high pollution load, high organic concentration and mixed solid and liquid.
Pig wastewater contains a lot of nitrogen and phosphorus. If nitrogen and phosphorus are discharged into the water body, it is easy to cause water eutrophication and pollute the water body. Nitrogen in water in the form of nitrate will cause harm to human health if it is drunk. The excess of nutrients in the soil will break the ecological balance of the land. The damage of antibiotics in excreta to human health has also attracted the attention of human health scientists and animal husbandry workers.
The following two treatment methods are generally adopted for the treatment of aquaculture wastewater:
- Physical treatment methods include: grid, sedimentation, filtration, etc.
The physical method is mainly to remove large suspended solids and impurities, feed residues, pig hair, pig urine and other substances that can block or wear pipes and pumps, as well as the reaction products of sewage after chemical treatment, activated sludge or biofilm generated after sewage biological treatment.
- Chemical treatment method chemical treatment is the use of chemical reaction to remove impurities in water.
Chemical treatment methods include coagulation, disinfection, neutralization, etc. Sewage chemical treatment objects include: dissolved harmful substances in sewage, such as acid, alkaline organic matter, and various organic solvents.