黑龙江流域水体和沉积物重金属的生态风险研究

Study on Ecological Risk of Heavy Metals in Water and Sediments in the Heilong River Basin

中国东北黑龙江流域作为重工业基地和商品粮基地,水体、沉积物和土壤的重金属污染非常值得关注。作者采集了黑龙江流域从上游干旱区到下游三江平原的河水、湖水、地下水和河床沉积物样品,分析重金属元素含量,运用不同指标评估了流域的水资源安全和沉积物的污染风险程度。研究结果显示,在黑龙江流域上游干旱区,部分地表水和地下水的As含量超过了中国生活饮用水卫生标准,最多接近7倍,上游地区居民的用水安全需要引起有关部门的关注。通过内梅罗指数法(P_(综合))和潜在生态危害指数(RI)的综合评估表明,黑龙江流域沉积物的总体生态风险较低。单个重金属元素中,Cd在大部分流域存在中等生态风险,有3个沉积物样品展现出较高生态风险。Cd作为危害中国耕地土壤和人类健康的主要重金属元素,在黑龙江流域同样也需要予以重点关注。

As a heavy industrial base and a commodity grain base in northeast China,the heavy metal pollution of water,sediment and soil in the Heilong River Basin is very worthy of attention.We collected the samples of river water,lake water,groundwater and riverbed sediment in the Heilong River Basin from the upstream arid area to the downstream Sanjiang Plain,and then analyzed the content of heavy metal elements,in order to reveal the water resources security and the degree of pollution risk of sediments by using different indexes.The results show that in the arid area of the upper reaches of the Heilong River Basin,the content of As in some surface water and groundwater exceeds the standard for drinking water quality(up to 7 times).Therefore,the safety of water for residents in upstream areas needs to be a concern.A comprehensive assessment of the indexes of P_(com) and RI shows that the overall ecological risk of sediments in the Heilong River Basin was low.Among single heavy metal elements,Cd has moderate ecological risk in most watersheds,and three sediment samples show high ecological risk.Cd,as the main heavy metal element endangering the soil quality and human health in China,also needs to be paid special attention in the Heilong River Basin.