我国农村生活污水污染排放及环境治理效率

当前我国农村生活污水治理形势依然严峻.利用第二次全国污染源普查成果，分析了我国2017年农村生活污水排放情况，并基于熵值法和数据包络分析（DEA）模型从技术效率、经济效率两个角度对治理效率进行评价.结果表明:①我国农村生活污水中COD排放量约占生活源排放总量的50.8%，NH₃-N、TN和TP排放量分别占生活源排放总量的35.0%、30.5%、38.7%，污水及污染物排放去向以直排入水体、直排入农田和其他途径为主，三者占80%以上.②我国沿海用水量较大地区的水冲式厕所比例超过80%，且农村生活污水有效治理比例仅为11.0%，导致我国农村生活污水治理的技术效率仅为8.6%，且区域差异较大，其中有23个省份小于10%，技术效率普遍较低.③相比浙江省、上海市、山西省、内蒙古自治区、青海省、西藏自治区等地（经济效率均为1），我国其他省份农村生活污水治理的经济效率有很大改善空间.农村生活污水中人均COD排放强度、人均NH₃-N排放强度与农村居民人均可支配收入之间的环境库兹涅茨曲线（EKC）均呈一定的倒“U”型关系，人均TN排放强度、人均TP排放强度与农村居民人均可支配收入之间的EKC则均呈“N”型特征，有波动上升趋势.研究显示，我国农村生活污水治理效率存在较大的提升空间，与城镇相比，农村的环境保护基础设施建设还比较落后，应以源头减量、分类处理、循环利用为导向，加强统筹规划，梯次推进，加快提升我国农村污水治理水平. 

Pollution Discharge and Environmental Treatment Efficiency of Rural Domestic Sewage in China

At present, the situation of rural domestic sewage treatment in China is still severe. Based on the results of the second national census on pollution sources, the situation of rural domestic sewage discharge in 2017 was analyzed and the technical efficiency and economic efficiency of rural domestic sewage pollutant treatment were evaluated with the entropy method and data envelopment analysis (DEA) model. The results showed that COD discharge of rural domestic sewage accounted for 50.8% of the total domestic sewage discharge, while NH₃-N, TN and TP accounted for 35.0%, 30.5% and 38.7% respectively. More than 80% of the pollutants were discharged directly into water bodies, farmland and other ways. Because the effective treatment ratio of rural domestic sewage was only 11.0%, and the areas with more than 80% of flush toilets were mainly located in the coastal areas with high water consumption, the average technical efficiency of rural domestic sewage treatment in China was only 8.6%, and the regional differences among provinces were significant, of which 23 provinces were less than 10%, and the technical efficiency was generally low. Compared with Zhejiang Province, Shanghai City, Shanxi Provence, Inner Mongolia Autonomous Region, Qinghai Provence and Tibet Autonomous Region, where economic efficiency was 1, the economic efficiency of rural domestic sewage treatment in other provinces of China still had great room for improvement. The Environmental Kuznets Curve (EKC) between the per capita pollutant discharge intensity of COD and NH₃-N in rural domestic sewage and the per capita disposable income of rural residents showed a certain inverted-U trend, while the EKC between the per capita pollutant discharge intensity of TN and TP in rural domestic sewage and the per capita disposable income of rural residents showed a N shape with a fluctuating upward trend. This study shows that there is a great potential for improving the treatment efficiency of domestic sewage in rural China. Compared with the urban areas, the rural areas still lag behind in terms of infrastructure for environmental protection, rural sewage treatment must be improved rapidly in the coming years.