海南小海沉积物中的重金属分布特征及潜在生态风险评价

Distribution and Potential Ecological Risk Assessment of Heavy Metals in Sediments from Xiaohai Bay, Hainan, China

对小海沉积物进行采集,测定了沉积物中的Cu、Pb、Cd、Zn、Hg、As重金属的含量,用单因子指数法和Hakanson生态风险指数法评价了沉积物中重金属综合污染效应。研究结果表明:小海湾内沉积物中Cu、Pb、Cd、Zn、Hg、As的平均含量分别为0.20mg/kg、0.18mg/kg、0.30mg/kg、0.22mg/kg、0.44mg/kg、0.23mg/kg。沉积物所监测的重金属中,Hg金属的空间波动程度最高,其他重金属的空间波动程度较低。沉积物质量评价结果表明:小海沉积物中主要的重金属污染因子是As,其重金属影响因子的顺序为As>Hg>Pb>Cr>Zn>Cu>Cd;各种重金属的潜在生态危害系数大小顺序为Hg>As>Cd>Pb>Cu>Cr>Zn;潜在生态风险指数RI平均值为37.06,属于轻微潜在生态风险。

According to the concentrations of Cu, Pb, Cd, Zn, Hg and As in the sediments from Xiaohai Bay, Hainan,China, the integrated pollution effect of heavy metals of these sediments is evaluated by the technique of single factor index and Hakanson ecological risk. The results show that the average concentration of Cu, Pb, Cd, Zn, Hg and As is 0.20 mg/kg, 0.18 mg/kg, 0.30 mg/kg, 0.22 mg/kg, 0.44 mg/kg and 0.23 mg/kg, respectively. It is shown Hg has the highest level of fluctuation in space and others have relatively low levels. It is revealed that the main pollution factor is As and the sequence of factor index is As〉Hg〉Pb〉Cr〉Zn〉Cu〉Cd. The sequence of ecological risk is Cd〉 Zn〉 Pb〉 Cu 〉 Cr and the potential ecological risk is Cd 〉 Pb〉 Cu〉 Zn〉Cr. The average potential ecological risk is 37.06,and it is therefore concluded that Xiaohai Bay has slight potential ecological risk.