再生水回灌条件下地下水重金属污染特征

Characteristics of Heavy Metal Pollution in Groundwater by Reclaimed Water Recharging

为了探讨再生水回灌条件下的地下水中重金属Fe、Mn、Pb、Se、Sr、Zn含量变化情况,在郑州回灌试验场采集并分析了再生水、河水、土壤水和地下水样品(共106个),研究了土壤水和地下水中重金属在再生水回灌过程中的变化情况。结果表明:地下水中Fe、Mn、Sr背景含量较大;回灌1 a后,Fe、Sr含量有所减小,但Mn、Pb、Se、Zn含量有所增大;再生水回灌引起的重金属含量增大的范围为地面以下15.0～20.0 m;引起地下水中重金属含量变化的原因除再生水的回灌以外,还有场地土壤和地下水中较高的重金属背景。

106 water samples including reclaimed water, river water, soil water and groundwater from the Zhengzhou recharge demonstration site were collected for heavy metal concentration analysis, aimed to explore the concentration of heavy metals Fe, Mn, Pb, Se, Sr and Zn in groundwa- ter which was recharged by the reclaimed water. The results show that a） Fe, Mn and Sr have high background levels in groundwater; b） after one- year recharging, the concentrations of Fe and Sr have been reduced, but Mn, Pb, Se. and Zn increased; c） groundwater in 15.0 -20.0 m below the surface is influenced by reclaimed water recharging in heavy metals concentration rising; d） the reason for the variation of the heavy metal com- ponents in groundwater is not only the reclaimed water recharging, but also the high levels of heavy metal background in the soil and groundwater.