三峡上游支流梁滩河底泥重金属分布及稳定化

Heavy Metal Distribution and Stabilizing Effects Mechanism of Liangtan River Sediments

摘要:

以梁滩河河道底泥为研究对象，对不同监测断面39个底泥样品的重金属含量及分布进行了测定，同时选取其中5个底泥样品，利用纳米铁粉对底泥中重金属进行了稳定化处理，并通过X射线衍射仪（XRD）对其稳定化机理进行了探讨.研究结果表明，梁滩河底泥已经不同程度地受到了Cu，Pb，As，Zn，Cd，Cr等重金属的污染，其中As的污染程度最严重，最高值达到了土壤背景值的110倍.添加纳米铁粉稳定化试剂后，As，Zn，Pb，Cr，Cu，Hg等重金属的浸出浓度都得到了较大程度的降低；XRD分析结果表明，添加纳米铁后，重金属的化学形态由游离态转变为稳定态是重金属浸出浓度降低的主要原因之一.

Abstract:

This paper presents a study of Liangtan River sediments to measure heavy metal contents and distribution in 39 sediment samples of different monitoring sections. Nano scale iron was chosen to determine its effects on heavy metal stabilization in five contaminated sediment, and its stabilization mechanism was analyzed by X Ray Diffraction (XRD). The results show that the sediments in Liangtan River are polluted by Cu, Pb, As, Zn, Cd, Cr. As is polluted the most severly, the highest value reaches 110 times of the soil background value. After adding nano scale iron, the concentrations of As, Zn, Pb, Cr, Cu, Hg are highly reduced. XRD analysis shows that the chemical form of heavy metals changing from the free state to steady state is one of the main reasons for the reduction of the leaching toxicity after adding nano scale iron.