State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
Water Res. 2011 Feb;45(4):1711-9. doi: 10.1016/j.watres.2010.11.022. Epub 2010 Nov 24.
Dissolved organic matter (DOM) plays an important role in heavy metal migration from municipal solid waste (MSW) to aquatic environments via the leachate pathway. In this study, fluorescence excitation-emission matrix (EEM) quenching combined with parallel factor (PARAFAC) analysis was adopted to characterize the binding properties of four heavy metals (Cu, Pb, Zn and Cd) and DOM in MSW leachate. Nine leachate samples were collected from various stages of MSW management, including collection, transportation, incineration, landfill and subsequent leachate treatment. Three humic-like components and one protein-like component were identified in the MSW-derived DOM by PARAFAC. Significant differences in quenching effects were observed between components and metal ions, and a relatively consistent trend in metal quenching curves was observed among various leachate samples. Among the four heavy metals, Cu(II) titration led to fluorescence quenching of all four PARAFAC-derived components. Additionally, strong quenching effects were only observed in protein-like and fulvic acid (FA)-like components with the addition of Pb(II), which suggested that these fractions are mainly responsible for Pb(II) binding in MSW-derived DOM. Moreover, the significant quenching effects of the FA-like component by the four heavy metals revealed that the FA-like fraction in MSW-derived DOM plays an important role in heavy metal speciation; therefore, it may be useful as an indicator to assess the potential ability of heavy metal binding and migration.
溶解有机质（DOM）在通过渗滤液途径将城市固体废物（MSW）中的重金属迁移到水生环境中起着重要作用。在这项研究中，采用荧光激发-发射矩阵（EEM）猝灭结合平行因子（PARAFAC）分析来表征 MSW 渗滤液中四种重金属（Cu、Pb、Zn 和 Cd）与 DOM 的结合特性。从 MSW 管理的各个阶段收集了 9 个渗滤液样本，包括收集、运输、焚烧、填埋和随后的渗滤液处理。通过 PARAFAC 鉴定出源自 MSW 的 DOM 中有三个类腐殖质成分和一个类蛋白成分。成分与金属离子之间观察到明显的猝灭效应差异，并且在各种渗滤液样本中观察到金属猝灭曲线的相对一致趋势。在四种重金属中，Cu（II）滴定导致所有四种 PARAFAC 衍生成分的荧光猝灭。此外，仅在添加 Pb（II）时观察到类蛋白和富里酸（FA）样成分的强烈猝灭效应，这表明这些部分主要负责 MSW 衍生 DOM 中 Pb（II）的结合。此外，四种重金属对 FA 样成分的显著猝灭效应表明，MSW 衍生 DOM 中的 FA 样部分在重金属形态中起着重要作用；因此，它可能作为评估重金属结合和迁移潜力的指标很有用。
