初期雨水溢流对河道纳污能力的影响分析

Impact Analysis of Initial Rainwater Overflow on River Pollutant Carrying Capacity

为减小初期雨水对河流的水质污染,进一步改善水体环境,采用SWMM排水模型模拟研究区不同重现期下的雨期管网运行情况,通过调节节点高程和调节管径的方式,优化改造管网模拟运行中出现的不足,进一步分析比较了雨水溢流情况对河道纳污能力的影响规律,并探讨了缓解溢流污染问题的思路。结果表明,COD、NH4-N、TP、TSS的最大溢流浓度均随重现期的增大而增大,平均溢流浓度随重现期的增大而减小;截流倍数为1,重现期为10、20年时,河道污染很轻;截流倍数调整为3后,初期雨水对河道纳污基本无影响。研究成果可为河流纳污能力分析与水环境保护提供技术支持。

By choosing proper drainage model,the running condition of the rain pipe network is simulated in different return period of the study area.By adjusting node elevation and pipe diameter,the deficiency appearing in the simulated network is optimized and transformed.Through analysis and comparison,the effect law of the rainwater overflow situation on the river pollutant carrying capacity is studied.At the same time,the ideas are discussed to alleviate the overflow pollution problem.The results show that the maximal overflow concentrations of COD,NH4-N,TP and TSS will rise with the increase of return period.The average overflow concentrations will decrease with the increase of return period.When the interception ratio is 1and the return periods are 10 or 20years,the degree of rive pollution is small.Meanwhile the interception ratio was adjusted to 3,the initial rainwater has no impact on the river pollutant carrying capacity.The research above offers technical support for the study of the river pollutant carrying capacity and water environment protection.