Study On The Treatment Process Of Rural Dispersed Piggery Wastewater

Dispersed piggery wastewater was produced by small-scale backyard farmers. The scale of farming was generally less than20. Piggery wastewater without effective treatment discharged into surface water due to the lack of cost-effective treatment measures. It caused serious pollution to the rural water environment. The environmental pollution had become the urgent problem during the new rural construction.Piggery wastewater in the Southern Hills was taken as the research object in this paper. Firstly, the farmers with less than20pigs were selected. The emission characteristics of piggery wastewater were studied in depth. Secondly, the environmentally friendly piggery was developed on the basis of the emission characteristics. It achieved the solid-liquid separation of pollutants. Combined with fluid mechanics and engineering principles, the liquid-liquid separation device was invented. The urine can be separated from rinse water by the device. The pollutant loads of wastewater were effectively reduced. The resource utilization of the pollutants was realized at the source. Taking into account the economy and operation, source separation-multistage anaerobic-constructed wetlands process was developed contrary to the characteristics of the piggery wastewater. The principle of biology, chemistry and ecology were also considered.The concentrations of chemical oxygen demand, ammonia, total nitrogen, total phosphorus, suspend solid in piggery wastewater were respectively1432～2068mg/L,152.8～214.5mg/L,206.3～263.6mg/L.14.6～23.4mg/L,1029～1584mg/L after source separation. The average removal rates of COD, BOD5, NH4+-N, TN,TP and SS in the anaerobic reactor were respectively60.8%,63.0%,11.5%,7.9%,15.0%and78.8%after stable operation. The removal performances of phosphorus and nitrogen were low in anaerobic reactor. The concentrations of COD, BOD5, NH4+-N, TP and SS were respectively354mg/L,135mg/L,69.4mg/L.4.9mg/L. and28mg/L after enhanced treatment of constructed wetland. The pollutant concentrations of effluent were lower than the specified values of Discharge Standard of Pollutants for Livestock and Poultry Breeding (GB18596-2001).The operation parameters of aerobic reactor were optimized in this paper. The readily available red soil and slag were used as substrates of constructed wetland. The treatment effect of constructed wetland was studied. The removal mechanisms of pollutants were analyzed in constructed wetland. The factors about treatment of dispersed piggery wastewater were discussed. It would provide theoretical and technical support for the promotion of integration process.