佛山市某区鱼塘中重金属污染调查及生态风险评价

Investigation and ecological risk assessment of heavy metal pollution in fish ponds in a district of Foshan City

为了解佛山市某区渔业养殖环境中重金属污染及生态风险,用原子吸收和原子荧光法测定了佛山市某区2个区域的13个鱼塘,各采集13个养殖水体和底泥样品,对6种重金属指标进行检测,并对底泥中的重金属污染程度和生态风险进行评价。结果表明:13个鱼塘水体中只有一个水样的Pb超过渔业水质标准,超标倍数为0.16,超标率为7.7%,其余水体中的5个重金属指标均未超过渔业水质标准。鱼塘底泥中潜在生态风险综合指数(RI):68.7~192.9,平均值130.3,生态风险等级是低风险。6种重金属指标的单项潜在生态风险指数平均值从大到小顺序:Hg>Cd>Cu>Ni=Pb>As,Hg和Cd属于中等生态风险,Hg和Cd是该区鱼塘养殖中潜在生态风险最大的元素。

In order to understand the heavy metal pollution and ecological risk in the fishery and aquaculture environment in a certain area of Foshan City,13 fish ponds in two areas of Foshan City were determined by atomic absorption spectrometry and atomic fluorescence spectrometry,13 aquaculture water and sediment samples were collected respectively to evaluate 6 heavy metal indexes,and the degree of heavy metal pollution and ecological risk in sediment were also investigated.The results showed that Pb in only one water sample of 13 fish ponds exceeded the fishery water quality standard,exceeding 0.16 times with the exceeding rate of 7.7%.The five heavy metal indexes in other water bodies did not exceed the fishery water quality standard.The comprehensive index(RI)of potential ecological risk in the sediment of fish pond ranges from 68.7 to 192.9,with an average value of 130.3,indicating the low ecological risk level.The average value of individual potential ecological risk index of six heavy metal indicators is in the following order from large to small:Hg>Cd>Cu>Ni=Pb>As,which means that Hg and Cd exhibit medium ecological risk,while Hg and Cd show the most serious potential ecological risk in fish pond culture in this area.