锰矿区锰与DOM相互作用机制及混凝去除机理研究

The heavy metal pollution to those water environments around the metal mining area is one of the most significant problems in the ecological environment. They are easy to combine with those dissolved organic matters (DOM) from water environment and soil thus generating new kinds of compounds during their filtration into the surrounding surface and groundwater through surface runoff. These compounds often contain greater toxicity and their treatments are therefore more difficult. Therefore, research on the interaction of DOM and the heavy metals as well as the pollution controlling is significant. In this project, the heavy metal (manganese) from the selected area (manganese ore in Xiangtan, China) is selected as the investigated objective. The correlation characteristics (between DOM fluorescence fractions and DOM, Mn, and Mn-DOM) and the relevant interaction mechanisms are revealed during the interaction analysis of manganese and DOM by three dimensional fluorescence spectra, fluorescence quenching technology and parallel factor analysis. Further researches are concentrated on preparing new materials and optimizing coagulation-flocculation process to establish an effective method for removing Mn and Mn-DOM, which will be benefit to the understanding of the coagulation mechanisms. Overall, this project intends to provide a theoretical support for controlling heavy metal pollution to those water environments in the metal mining area.

金属矿区水环境重金属污染是我国生态环境面临的重大问题。当重金属通过地表径流、下渗进入矿区周边地表及地下水体过程中，容易与水环境、土壤中溶解有机质（DOM）结合，形成毒性更大的重金属-DOM复合污染物，加大重金属治理难度。因此研究金属矿区周边地表及地下水体中重金属与DOM结合形态及污染治理意义重大。本研究拟以湘潭锰矿重金属锰离子为代表，应用三维荧光光谱，结合荧光猝灭技术与平行因子法分析重金属锰离子与DOM中不同荧光基团配位过程，研究配位过程中DOM荧光组分与DOM含量、Mn含量、Mn-DOM含量的相关性特征，阐明其相互作用机理；制备新型混凝材料，优化混凝过程及探究混凝机理，建立混凝去除锰矿区周边地表及地下水环境中锰与Mn-DOM复合污染物的方法。为有效治理金属矿区重金属水环境污染奠定理论基础和方法。

锰矿区地表水中锰（Mn）与溶解性有机物（DOM）及其复合污染物Mn-DOM的污染是锰矿区水环境治理的重中之重。本项目以锰矿区为研究区，通过实际取样、测试分析，对锰矿区污染程度进行了了解，结合模拟水样对矿区污染治理开展了研究。.（1）结合锰矿区实际，在充分采样的基础上对矿区锰、腐殖酸污染进行了评估，确定了污染大致浓度范围，结合三维荧光光谱与紫外光谱分析进行了Mn与DOM的络合机制研究。.（2）通过对常见的有机高分子混凝剂聚丙烯酰胺（PAM）进行优化制备，并以其为原料通过酰胺化反应，将还原型谷胱甘肽（GSH）上的重金属强配位基团接枝到 PAM 分子链上，制备出新型巯基化高分子混凝剂（PAM-GSH）。在PAM 本身所具有的较好的吸附架桥能力的基础上，强化了其对重金属配位螯合的能力。使之成为含巯基的有机高分子混凝剂，更加有效地去除水中的重金属Mn、Cu、Cd。.（3）以硫酸亚铁和硫酸铝为原料，通过浓硝酸将Fe(Ⅱ)氧化为Fe(Ⅲ)，加入磷酸氢二钠作为稳定剂，经微波引发通过水浴反应制备了高分子无机混凝剂聚合硫酸铝铁（PAFS）。将在最优制备条件所得的产物用于水中腐殖酸的去除。对优化条件下的PAFS与实验室前期制备的高分子混凝剂（PAM-GSH）按一定比例进行复合得到有机-无机复合混凝剂聚丙烯酰胺-谷胱甘肽-聚合硫酸铝铁（PAM-GSH-PAFS）。同时以Mn(Ⅱ)与DOM的混凝水样为模拟水样，通过强化混凝研究了复合混凝剂PAM-GSH-PAFS对水中Mn(Ⅱ)与DOM的去除效果。