Multilevel Recycling Waste Water of Raising Pigs Based on Local Farming Model and Its Effect Evaluation

摘要

A large-scale pig farms in Jiangxi Province was researched,a model of resource utilization for breeding wastewater was established with methane tank →clarifier →reservoir breeding →farmland irrigation.The results showed that the concentrations of COD,ammonia nitrogen and total phosphorus of the treated wastewater were 59.13mg/L,1.15mg/L and 0.015mg/L respectively,the degradation rates of which were 24.2％,99.34％,93.85％ separately.The fish bait of reservoir for fish culture was saved by discharging certain concentration wastewater into it while the organic matter in the aquiculture wastewater was degraded by ecosystem.The reservoir water was used later as irrigation water and organic matter in the aquieulture wastewater was degraded thoroughly,which decreased the cost of discharging sewage from farms,eliminating pig emission pollution to the environment and increasing crop yields.The above model was an ecomodel,not only treating cultivating wastewater but also recycling the waste water.The management of piggery wastewater and monitoring of reservoir water quality were suggested in order to avoid water eutrophication.