太湖主要入湖河流排污控制量研究

Study on the Sewage Control Amount of Main Into-lake Rivers around Taihu Lake

利用2006—2008年的监测数据对太湖主要入湖河流的水环境状况进行了分析,通过对研究区工业污染源、农业污染源和城镇生活污水排污的分布以及入河情况的调查,对各种污染源的入河量进行了计算,根据确定的水质目标,分别计算出主要入湖河流以及区域水系的水环境容量和排污控制量。结果表明:15条主要入湖河流超标现象显著,近3a来污染程度有所波动,N、P污染最为严重。研究区内污染物入河量较大,未接管的生活源污染物入河量所占比重最大,各类污染物均在50%～60%之间;张家港市的污染物入河量最大,各类污染物所占比重达总入河量的18%～20%。研究区内河网密布,水环境容量分布不均匀,望虞河、直湖港、武进港等7条河流水环境容量较大,张家港市区域水环境容量较大。为保证水质达标,研究区内近期共须削减CODCr66554.38t/a、NH4-N8105.71t/a、TP1324.42t/a;远期共须削减CODCr96719.08t/a、NH4-N11541.45t/a、TP1788.71t/a。

Water environmental problems of main into-lake rivers were analyzed in the present study according to the monitoring data from 2006 to 2008.Through the investigation on the distribution and sewage amount of the industry pollution source,agriculture pollution source and the urban sewage source in studied region,total amount of pollutant drainage into the rivers was calculated.According to the water quality target,the water environment capacity of main into-lake rivers and the studied region,as well as the sewage control amount were calculated.Results showed 15 rivers significantly exceeded the water quality standards,and pollution level of the rivers erratically changed in the recent 3 years and the serious pollution factor was NH4-N.Pollutants load into rivers were very large.Domestic pollution source not takeover had the largest pollution load contribution with the proportion between 50% and 60% and Zhang jia-gang got the largest proportion between 18%~20% compared with the other cities.There are many rivers in the studied region and the distribution of the water environment capacity is not homogenous.Wangyu river,Zhihu river,Wujin river and other 4 rivers have relatively large water environment capacity,and Zhang jia-gang has relatively large region water environment capacity.About 66554.38 t/a COD,8105.71 t/a NH4-N and 1324.42 t/a TP should be cut down recently and 96719.08t/a COD,11541.45t/a NH4-N and 1788.71t/a TP should be cut down in forward future to ensure the water quality reach the standard.