Application of aerobic biological filter for treating swine farms wastewater

Abstract In this paper, aerobic biological filter is applied to treat swine farms wastewater. Laboratory experiments are conducted to confirm the optimum parameters for start-up and operation of filter by investigating the effect of temperature on the start-up of the filter and the influence of temperature, pH value and recirculation rate on the treatment effect of the filter. The results show temperature increasing is benefit for accelerating start-up of filter in the range of 17.0-33.0°C. COD removal of the filter enhances slightly by temperature rising during normal operation. High NH3-N reduction (above 84.0%) is obtained in range of 25.0-30.0°C. pH in range of 7.1-8.0 is recommended for operation treatment, in which pollutants reduction for COD and NH3-N is 85.7%-86.9 and 86.8%-89.5%, respectively. COD and NH3-N reduction enhances with recirculation rate increasing. When the recirculation rate is above 4, the increasing of COD and NH3-N reduction is slight. Swine wastewater treatment project utilizing aerobic biological filter as a key element is established in a swine breeding farm of Daxing district, Beijing. The whole project runs well by start-up and operation of filter. COD reduction of wastewater in aerobic biological filter is 63.0-89.3%. And the COD concentration of effluent in filter is below 150 mg/L, which achieves the national requirement of pollutants output standard of livestock and poultry breeding industry and water quality standard of farmland irrigation. The aerobic biological filter is worth to be generalized for treating swine wastewater in China.