石臼湖表层沉积物营养盐与重金属分布及污染评价

为揭示石臼湖表层沉积物营养盐和重金属的污染特征,于2018年2月采集表层沉积物,分析了石臼湖营养盐和重金属的含量、空间分布特征。结果表明:全湖有机质、TP和TN的平均质量比分别为30.25 mg/kg、585 mg/kg和776 mg/kg,TP为无污染风险级别,有机质和TN处于低污染风险级别;重金属Cr、Ni、Cu、Zn、As、Cd、Hg和Pb平均质量比分别为94.92 mg/kg、41.25 mg/kg、38.42 mg/kg、124.33 mg/kg、16.48 mg/kg、0.17 mg/kg、0.05 mg/kg和35.92 mg/kg,均超过了江苏省的土壤重金属背景值,Hg和Cd污染相对较重,全湖为中等危害等级;在空间分布上,东部区域的采样点8、9营养盐质量比较高,重金属污染较重。

Distribution of nutrients and heavy metals in surface sediments of Shijiu Lake and its pollution assessment

In order to reveal the pollution characteristics of nutrients and heavy metals in the surface sediments of Shijiu Lake,surface sediments were collected in February 2018,and the contents and spatial distribution of nutrients and heavy metals in Shijiu Lake were analyzed.The results showed that the average values of organic matter,total phosphorus and total nitrogen were 30.25 mg/kg、585 mg/kg and 776 mg/kg,respectively,and total phosphorus were in no ecological risk level,organic and total nitrogen were in low ecological level;The average values of Cr,Ni,Cu,Zn,As,Cd,Hg and Pb were 94.92 mg/kg,41.25 mg/kg,38.42 mg/kg,124.33 mg/kg,16.48 mg/kg,0.17 mg/kg,0.05 mg/kg and 35.92 mg/kg,respectively,all of them exceeded the background values of heavy metals in soils in Jiangsu Province.Hg and Cd pollution is relatively heavy,and the whole lake is of medium hazard grade.In the spatial distribution,the nutrient quality of sampling sites 8 and 9 in the eastern region was higher,and the heavy metal pollution was more serious.