云南分散畜禽养殖密集型农村污水特征及污染风险评价

CHARACTERISTICS OF SEWAGE POLLUTION AND ENVIRONMENTAL RISK ASSESSMENT OF DISPERSION LIVESTOCK INTENSIVE VILLAGE IN YUNNAN

农村污水是造成水环境污染的主要原因之一,它不仅是农村水源地的安全隐患,还会危害农民自身的生存发展,因此对农村污水特征分析及风险评价具有重大意义。通过对云南省文山州八道哨村(畜禽养殖型)的农村污水进行采样和处理,分析了总磷、正磷、总氮、氨氮、COD、p H等污染指标,明确了畜禽养殖型农村污水的污染特征状况。结果表明:每个样点排放污水的氮和COD浓度均超过了GB 18918—2002《城镇污水处理厂污染物排放标准》,磷的浓度整体超过污染标准,仅有个别样点位于正常范围内;主干道污水的氮、磷和COD浓度均明显超过GB 18918—2002二级标准。通过运用内梅罗指数法对各污染指标进行统一处理,评价不同区域污水的污染程度。3个分区的内梅罗指数大小依次为东部(4.55)>中部(3.34)>西部(3.14),污染等级均为重污染。

Rural sewage is one of the main causes of water pollution. The village sewage is not only a hidden danger in the rural water source,but also harmful to the survival and development of the farmers themselves,so it is critical to analyze the rural sewage characters and evaluate the risk. The paper collected the rural domestic wastewater in Badaoshao Village,Wenshan Prefecture,Yunnan Province,analyzed the pollution index,such as total phosphorus,phosphorus,total nitrogen,ammonia nitrogen,COD,p H and so on,and defined the characteristics of pollution of livestock and poultry farms in rural areas. The results showed that： The concentration of nitrogen and COD of rural sewage in every point significantly exceeded the national secondary standard of village sewage,and the concentration of phosphorus exceeded the pollution standard,only few sample points belonged to the normal range; the concentration of nitrogen,phosphorus and COD of sewage in main trunk obviously exceeded the national secondary standard of munipal sewage. By using the method of Nemero index to deal with the pollution index as a whole,the pollution degree of different regional sewage was evaluated. The result showed that： The size of Nemerow index in three areas were eastern（ 4. 55） central（ 3. 34） western（ 3. 14） in turn,and the level of pollution were all seriously polluted.