嘉陵江入江河段沉积物重金属污染状况评估

ASSESSMENT ON HEAVY METAL POLLUTION IN THE SEDIMENT OF INFALL REACH OF JIALING RIVER

为了解三峡水库175m蓄水前典型支流沉积物中重金属污染程度及其对水生生物的风险状况,在对嘉陵江入江断面10余年连续监测的基础上,利用地积累指数法对金属污染程度进行了评价,采用对数衰减模型对金属污染产生水生生物毒害的风险进行了评估,使用对数衰减模型进行毒性评估在国内尚属首次.评价结果表明,嘉陵江入江断面沉积物污染程度较轻,对水生生物风险较小,各污染物的污染程度大小排列次序为:Hg>Zn>Pb>Cd>As>Cu;各污染物对嘉陵江水生生物构成风险的排列次序为:Hg>Zn>Pb>As>Cd>Cu.

In order to investigate the magnitude of heavy metal pollution and the potential toxic effect in the sediment of the infall reach of Jialing river,based on the annual monitoring data of more than 10 years,the Index of Geoaccumulation was used to evaluate the extent of heavy metal pollution. And the logistic regression model was used to predict the toxic effect on aquatic life.The results show that the infall reach of Jialing river has only been slightly polluted by heavy metals and has low possibility to poison aquatic life.According to the Index of Geoaccumulation,the order of the analyzed heavy metals,arranged from highest to lowest pollution degree,was as follows：Hg〉 Zn〉 Pb 〉Cd 〉As 〉Cu;the probability of toxic effect was：Hg〉Zn〉Pb〉As〉Cd〉Cu.