水库底泥重金属污染物静态释放规律

Static Release of Heavy Metals from Sediments of Reservoir

为了探求水库底泥中重金属污染物的释放情况,分别对某水库表层底泥和底层底泥中重金属污染物进行静态释放模拟实验,得到了Cr、Pb、Ni、Zn和Cu5种重金属的释放浓度曲线,并分析了释放曲线的浓度变化趋势,通过计算得出了重金属污染物的释放速率及年释放量。结果表明,该水库底层底泥中重金属污染物的释放浓度比较低,对上覆水水体水质影响较小;而表层底泥中重金属污染物的释放浓度相对较高,对上覆水水体水质影响较大;5种重金属污染物Cr、Pb、Ni、Zn和Cu在表层底泥中其释放速率和年释放量都要比底层底泥中约高1个数量级。

The sediment is an important part of aquatic ecosystems, as the accumulation of various nutrients and pollutants among other ingredients in reservoirs. This paper studies the release of heavy metal pollutants from sediments of a reservoir, through simulation experiments with heavy metals, Cr, Pb, Ni, Zn and Cu, focusing on the static release of heavy metal pollutants in surface sediments and bottom sediments of a reservoir. The release concentration curves of 5 kinds of heavy metals Cr, Pb, Ni, Zn and Cu are obtained, and the concentration change trend of the release curve are analyzed. In addition, the pollutant release rate and the release amount of the heavy metals are calculated. It is shown that the release concentrations of heavy metals in the bottom sediment of the reservoir are relatively lower than those in the surface sediment and have relatively smaller impact on the overlying water quality too. The release rate and the release amount of the heavy metals in the surface sediment are higher than those in the bottom sediment by about one order of magnitude.