水丰湖流域沉积物、底质营养物及重金属含量调查与评价

Nutrients and Heavy Metals in Sediments and Substrate of Shuifeng Lake Basin:Investigation and Evaluation

为评价水丰湖流域沉积物与底质中富营养化和重金属累积的环境风险,于2014年5月(平水期)、8月(丰水期)和11月(冰封期)在水丰湖流域9个采样点中采集沉积物和底质样本,分析沉积物和底质中总氮(TN)、总磷(TP)、有机质、锌(Zn)、镉(Cd)、铬(Cr)、铅(Pb)、汞(Hg)、铜(Cu)、镍(Ni)、砷(As)的含量,应用水体底质有机污染评价标准和Hakanson潜在生态风险评价方法对水丰湖富营养化程度和重金属的污染水平进行评估。结果显示,水丰湖流域沉积物和底质的TN含量分别为0.172%和0.167%,大部分点位(17/27和16/27)处于丰富状态,TP的含量分别为0.192%和0.174%,总体(25/27和20/27)处于丰富状态。沉积物、底质的有机质含量平均值分别为29.85、27.87 g/kg,均为较低程度。重金属方面,Hg和Cu的污染较为严重,大部分采样点(7/9)为中等程度污染,且有较高程度的潜在风险。综上,水丰湖流域的沉积物和底质的营养含量较为丰富,个别重金属(Cu、Hg)含量超标,尚未发生重大污染,但需要加强营养物质和重金属累积的管控。

To evaluate the environmental risk of eutrophication and heavy metal accumulation in sediments and substrate of Shuifeng Lake basin,in May(normal water period),August(high water period)and November(freezing period)of 2014,sediment and substrate samples were collected from 9 sampling points in the Shuifeng Lake basin.The contents of total nitrogen(TN),total phosphorus(TP),organic matter,Zn,Cd,Cr,Pb,Hg,Cu,Ni and As in sediments and substrate were analyzed,and the eutrophication and heavy metal pollution were evaluated by using the organic pollution evaluation standard of water substrate and the Hakanson potential ecological risk evaluation method.The results showed that the content of TN in sediments and substrate was 0.172%and 0.167%,respectively,which was generally in a rich state(17/27 and 16/27).The content of TP was 0.192%and 0.174%,respectively,which was at a high level(25/27 and 20/27).The average content of organic matter in sediments and substrate was 29.85 g/kg and 27.87 g/kg,respectively,showing a low level.In terms of heavy metals,the pollution of Hg and Cu were relatively serious,and most of the sampling points were moderately polluted(7/9),and there was a high degree of potential risk.In general,the eutrophication of sediment and substrate in Shuifeng Lake basin is high,and the contents of some heavy metals exceed the standard.Although serious pollution has not occurred,it is necessary to strengthen the control of the accumulation of nutrients and heavy metals.