河流污染混合区的解析计算方法

Analytic method for pollutant mixing zone in rivers

以顺直宽矩形明渠中垂向线源等强度排放物质浓度分布的解析解为基础,探讨了污染混合区的计算方法,推导了污染混合区最大长度、最大宽度与相应纵坐标、面积以及最大允许污染负荷的理论计算公式,进行了污染混合区的算例分析。其结果可以作为河流污染混合区允许范围和最大允许污染负荷的计算依据,解析计算方法比采用二维水质模型进行污染混合区的计算更加快捷灵活、方便实用。给出了非保守物质污染混合区最大长度的理论计算公式和忽略反应降解作用按保守物质处理的条件:降解数De≤0.027。

On the basis of the theoretical solution to the concentration distribution under the conditions of the invariableness continuous plumb line source in the straight width rectangle of the river, this paper discusses the analytic method of the pollutant mixing zone in rivers, and deduces the largest length of the pollution mixing zone, the largest width and its corresponding formula of longitudinal coordinate, the area and the largest allowable pollutant load. The example analysis of the pollutant mixing zone is conducted. The result indicates that the analytic method can be used for the analytic gist of the outfall＇ s pollutant mixing zone in the allowable range and the largest allowable pollutant load, and the theoretical calculation is faster, more flexible, more convenient and more practicable than the 2D water quality model used for the calculation of the pollutant mixing zone. The paper gives the largest length calculation formula of the non-conservative substances pollutant mixing zone and the condition, neglecting the reaction and the decay effect and dealing with it based on the conservative substance. The formula of the decay number （De） is as follows： De≤0.027.