珠江口滨海湿地沉积物重金属污染现状及潜在生态危害

Pollution and Potential Ecological Risk of Heavy Metals in Sediment of Coastal Wetland of the Pearl River Estuary

根据2007年和2008年对珠江口滨海湿地6条代表性调查断面的表层沉积物取样调查,分析了表层沉积物中重金属的含量。结果表明:表层沉积物中铜、铅、锌、砷、铬、镉和汞的平均含量分别为56、43、139、29、31、0.96和0.10mg/kg,其中除铬外,其余6种元素的浓度均已超过I类海区沉积物标准,尤其铜污染最为严重。采用Hakanson潜在生态危害指数法对其生态危害程度进行了评价,镉在淇澳岛和磨刀门调查断面存在强和很强的潜在生态危害,总体潜在生态危害属中等,应当引起重视;其余各调查断面属轻微生态危害。

The surface sediments in six representative research zones around the Pearl River estuary were sampled in 2007 and 2008. The contents of copper, lead, zinc, arsenic, chromium, cadmium and mercury in the sediments were measured. The results were that the average contents of Cu, Pb, Zn, As, Cr, Cd and Hg were respectively 56 mg/kg, 43 mg/kg, 139 mg/kg, 29 mg/kg, 31 mg/kg, 0.96 mg/kg and 0.10 mg/kg, The average contents of those heavy metals, except chromium, have exceeded the National Standard for the sea area of class I, especially the pollution of copper was the most serious. In the paper the method of potential ecological risk index presented by Lars Hakanson is used to assess the heavy metals＇ ecological risk. It is shown that the potential ecological risk of Cd in surface sediments of the Qi＇ao island and Modao estuary was ＂high＂ and ＂higher＂, and their whole potential ecological risk of all heavy metals was ＂middle＂, while the whole potential ecological risk of the other research zones was lower.