中文摘要：

针对困扰排污口位置优化设计与排污削减量计算的实际问题,基于宽阔河流岸边、离岸与中心排放的分类准则,克服理论方法繁琐的试算比较过程,以显函数的形式提出了污染混合区无量纲最大长度、最大宽度及面积的分类简化计算公式和最大控制排污量的计算方法。在河流岸边（近岸）、离岸与中心排放类型条件下,以应用实例给出了根据离岸系数η进行污染混合区范围计算和排污口位置优化设计以及排污削减量计算的方法步骤。计算结果表明：在具体工程设计中,排污口的离岸距离与排污削减量可通过经济技术比较进一步核定。结果可为河流排污口位置的优化设计和控制排污量、排污削减量计算提供分类、简便、快捷的方法依据和设计范例。

英文摘要：

Optimization of sewage outfall location and reduction of the pollutant discharge are complex environmental issues in reality. A set of simplified,classified equations that are categorized for river bank,off-bank and river center discharging were proposed to predict the non-dimensional maximum length,maximum width and area. Using these equations can avoid the complicate trial-and-error progress in the theoretical method. According to the off-bank coefficient η,procedures of calculation in real applications and examples were demonstrated in the prediction of pollutant-mixing zone range,the optimization of outfall locations and the pollutant discharge reduction under the river bank（near-bank）,off-bank and river center discharge conditions. In specific engineering project design,the off-bank distance of the sewage outfall and the sewage reductions can be verified by considering from both the economic and technical aspects. The result provides aclassified,simple and convenient theoretical method and design examples for the optimization of outfall location and for the pollution load reduction calculation.