Stady On Wastewater Treatment In A Scale Pig Farm

The large amount of piggery wastewater from the farm is mostly emitted directly without appropriate recycle and treatment, which bring about a serious pollution to the environment. The piggery wastewater has the characeristic of high orgaism, suspending substance(SS), ammonia, etc. Treating piggery wastewater mainly adopt the methods of anaerobic digestion and aerobic digestion processing combined with physical-chemical and natural processing. Anaerobic ammonia oxidation(SBR) is a new biological deoxy technology which has very high value for development. The paper adopts anaerobic baffled reactor(ABR)-SBR to treat piggery wastewater and explores its feasibility and efficiency. The main conclusions are as follows:(1) When piggery wastewater is treated by ABR-SBR system, the removal rate of COD is about 96%, and the removal rate of NH3-N is about 87%. The concentration of COD in effluent is mostly under 400mg/L, and the concentration of NH3-N in effluent is under 70mg/L. The treated wastewater could meet the discharge standard of pollution.(2) In different hydraulic retention time(HRT) condition, HRT is directly proportional to the removal rate of COD. The longer HRT is, the higher the removal rate of COD is. In the economic perspective, the best HRT to treat the piggery wastewater is 24h, and the up-flowing rate should maintain 0.15m/h.(3) Investigating of the removal rate of COD, the output of methane and VFA (volatility fatty acid) of each compartment of ABR reactor, it finds that the first compartment of ABR reactor is the district of hydrolysis acid, the second and third compartments are districts of producing hydrogen and acetic acid, and the fourth and fifth compartments are districts of producing methane.(4) It analyses the technology's feasibility and the advantage.