利用开封市用水资料，计算了开封市区农业灌溉、市政用水、工业用水可利用的回用水量。由于污水的农业回用涉及到许多环境问题，因此根据开封市具体实例分析了污水的农业回用对灌区土壤中As、Pb含量、小麦品质、地下水水质和居民健康的影响。同时，运用费用效益基本理论，选择了市场价值法、影子工程法和人力资本法对灌溉带来的直接效益和间接效益进行了计算，并折算为单方水的效益。最后对比单方水灌溉费用，得到污水灌溉的单方水净效益，以此分析了开封市污水农业回用的费用效益。

According to the municipal water utilization data in Kaifeng, the amount of reused sewage from agricultural irrigation, municipal, and industrial water consumption were calculated. Because the sewage reuse in agricultural irrigation involves many environmental problems, this paper analyzes the impacts of sewage irrigation on the As and Pb contents in soil, wheat quality, quality of groundwater, and health of the residents in the irrigation district. In addition, based on the basic cost-effectiveness theory, the market value method, shadow engineering method, and human capital method were selected to calculate the direct and indirect benefits resulting from irrigation. These benefits were converted to the benefit of one cubic meter of water.Finally, the net benefit of sewage irrigation was obtained by comparing the irrigation cost and benefit of one cubic meter of water, which offered the insights for the cost benefit of sewage reuse in agricultural irrigation in Kaifeng.

国家自然科学基金资助项目(50849047)；河南省科技攻关重点项目(000291)