纳污河道水环境自净容量的精确计算方法

Accurate Calculation of Capacity of Aquatic Self-purification in Polluted River

以河流岸边排放为例讨论了环境容量的计算问题。作者认为 ,对环境容量精确的计算应根据污染物在河流中的扩散过程和发展的不同特点 ,将排污河段水体自净容量分段进行计算。对于上游来流所代入河段的污染物 ,在入口断面假定均匀分布 ,进口断面下游整个河段的浓度分布计算中 ,按纵向离散来处理。从排污口新加入的污染物在河段的扩散按扩散特点分三段来分别计算。排污口到污染带扩散至全河宽之间的河段按污染带形式来处理。污染带扩散至全断面到全断面均匀混合之间的河段作为单独一段来计算。这一段既有横向扩散也有纵向离散。从污染物在断面上均匀分布开始的下游河段其浓度变化亦应按纵向离散来处理。按上述原则 ,导出了精确计算公式。

The diffusion characteristics and formation of polluted belt have to be considered for an accurate calculation of capacity of aquatic self purification in polluted river. It is point out that the river must be divided into different parts for calculation of aquatic self purification. From outlet to the section where polluted belt is expanded to whole section, the concentration distribution is treated as polluted belt. From the section where the polluted belt is expanded to whole section to the section where the concentration distribution is uniform, pollutant exists in both transversal diffusion and longitudinal dispersion. From the section where concentration is uniform, there is only longitudinal dispersion. According to the principle mentioned above, the method of accurate calculation is present in this paper.