汤浦水库沉积物碳、氮、磷的分布与评价

目的]研究汤浦水库沉积物中氮、磷及有机碳等污染物现状,为水质安全保障提供依据。方法]在库区采集沉积物柱状样品,分析其中碳、氮、磷的含量,并采用有机指数法对沉积物污染现状进行评价。结果]沉积物中有机碳平均含量12.23g/kg,总氮平均含量1.22g/kg,总磷平均含量为0.49g/kg;氮、磷及有机碳等污染物主要集中于沉积物表层0—20cm范围内。随沉积物厚度的增加,各类污染物含量下降,40cm以下的沉积物中污染物含量变化不大;有机指数评价结果显示,水库沉积物有机指数为0.13,等级为Ⅱ级,较清洁。结论]汤浦水库沉积物受到的污染较小,但沉积物中含氮物质略多,应该引起重视。

Spatial Distribution and Pollution Evaluation of Sediment Carbon, Nitrogen and Phosphorus in Tangpu Reservoir

Objective] The spatial distribution of nutrients and pollution status of Tangpu reservoir were elucidated to provide relevant basis for water quality protection.Methods] The contents of total organic carbon (TOC),total nitrogen (TN),ammonium-nitrogen (NH4+-N),nitrate-nitrogen (NO3-N),total phosphorus (TP) and available phosphorous were analyzed.Meanwhile,the sediment pollution status was assessed using organic nitrogen index (ON) and organic index(OI).Results] The mean contents of TOC,TN and TP in the basin were 12.23 g/kg,1.22 g/kg and 0.49 g/kg,respectively.In 0-20 cm layer of sediment,TN,TP and TOC concentrations are higher than those in other layers of sediment.With the increase of sediment depth,the content of pollutants decreased.The concentrations of pollutants are roughly constant below 40 cm.The organic index of the sediment is 0.13 (level Ⅱ).Conclusion] The pollution of sediment in Tangpu Reservoir is slight,but the content of nitrogen is high.Therefore,attention should be paid to the nitrogen pollution in the sediment.