Research On The Piggery Wastewater Treatment By MBR

Swine wastewater has considerable amounts of organic matter and high concentrations of nitrogen and phosphorus, it has become the main pollution source in many districts of China. The conventional treatment methods cost much and need much land, but the effect was not so good, an economic and efficient treatment method is needed.Coagulation is a widely adapted method in the wastewater treatment for it is economic and convenient. The membrane bioreactor (MBR), which combines biological treatment and membrane separation, is a new technology for wastewater treatment. Wastewater treatment by means of MBR can greatly save water resources, equipment and operating cost, reduce land occupied by equipment. At the same time, MBR has many good characters such as high automation, convenient fitting and maintaining, etc. It has a promising application future.Comparing the effect of swine wastewater treatment by different coagulants, the best coagulant and its optimum dosage was determined. To assess the feasibility of MBR treating swine wastewater, we carried out two pilot scale experiments. At last the cost of the treatment of swine wastewater by MBR was analyzed.The results of the experiments showed that:1) PFS had the best flocculation effect treating swine wastewater, and its optimum dosage was 300mg/L,while the combination of PFS and CPAM presented even better flocculation effect than PFS, and its optimum dosage was 3mg/L.2) The COD and NH3-N removal rates of anaerobic digested effluent of swine wastewater treated by MBR were 89.7% and 37% respectively. The MBR system was with the strong capacity of resist shock sewage loadings.3) The results of engineering practice treating swine wastewater showed that the average removal rates of COD,NH3-N,TP by flocculation were 44.7%,9.8%,31.8%,respectively, as the dosage of PFS was 200mg/L ,the organic loadings were reduced effectively. The COD,NH3-N,TP,SS removal rates of MBR were 87.1%~93.4%,79.1%~88.7%,84.4~90.3% and 100%,respectively, the effluent met the requirement of Discharge standard of Pollutants for Livestock and Poultry Breeding.4) The cost of the treatment of swine wastewater by MBR system was 2.08yuan/t.5) Swine wastewater treatment by using MBR was economic and feasible.