Study On Surface Water Environmental Capacity In Zigong City

This paper studied the water quality status, pollutant and its discharge condition, and the water environmental capacity of all rivers in Zigong City. Based on the investigation of environmental mateirals, contamination condition of the main rivers was analyzed in the paper. It was shown that the water environmention of Zigong city was deteriorated in general, especially in Fuxi River and Xushui River, and the main contaminative indexes of NH₃-N, BOD,COD_Mn, and or so. According to investigating and evaluating pollution fountainhead of industry,living and non-point fountainhead. Total Wastewater is 356486400 t/a, COD is 20786 t/a, NH₄⁺-N is 3338.84 t/a.; according the quantity of wastewater, main the non-point fountainhead, according the thickness of wastewater, main the point fountainhead, according the scull canton, the most graveness is the cantonal. Based on comprehensive assessment of water quality and analysis of pollution fountain, according to the principle of maximal contamination tolerance, water environmental capacity of Zigong City was computed by using one-dimension model. The result showed that the water environmental remaining capacity for COD was 25769.2 t/a, and for NH3-N was 2842.6 t/a, then the cut portion for COD was 94.9 t/a, and for NH3-N was 2034.2 t/a.This study can offer important gist for the quantitative management of Zigong city water environment, in the meanwhile, its thought and method can be used in the similar work of other areas for reference.