太湖流域某城市老城区水系总磷污染特征及成因分析

Pollution Characteristics and Causes of Total Phosphorus in The Water System of Downtown in A City of Taihu Basin

对太湖流域某城市老城区主要水系总磷浓度的时空变化情况进行了分析。结果表明,地下水中总磷浓度在同一时间段内,从上游到下游波动较大,且敞口井的总磷浓度高于封口井;地表水中总磷浓度4月到6月86.1%满足《地表水环境质量标准》中IV类水质标准,38.8%满足Ⅲ类水质标准,而7月份总磷浓度则全部超过IV类水质标准;从4月到7月,城市内河总水系(关河—北市河—东市河)中总磷含量从上游到下游呈递增趋势;在支流北市河中从上游到下游亦呈递增趋势。

Space--time variations of total phosphorus were analyzed in the water system of downtown in a city of Taihu basin. The results showed that the content of total phosphorus varied a lot in groundwater from upstream to downstream. And the total phosphorus contents in the open wells were higher than that in the closed wells. In the surface water, from April to June, 86.1% of the samples TP concentration meet the standard of IV level in Environmental Quality Standards for Surface Water, and 38.8% meet the standard of Ⅲ level. And in July, the total phosphorus contents all overrun the stardand of Ⅳ level. In general, from April to July, there was a increasing trend from upstream to downstream in the downtown water system （Guan River--Bei Shi River--Dong Shi River） and in the branch of Bei Shi River.