模拟湿地植物根系分泌物对酸性矿山废水沉淀物中Fe、Mn释放及形态的影响

发布时间：2018-10-13 13:35

【摘要】：为研究人工湿地处理酸性矿山废水(acid mine drainage,AMD)系统中植物根系分泌物对根际环境沉淀物中Fe、Mn活性的影响,评估人工湿地处理AMD时对Fe、Mn固持作用的稳定性及可靠性,选用植物根系分泌物中常见的柠檬酸、苹果酸及草酸来模拟植物根系分泌物对沉淀物中Fe、Mn的释放及形态影响。结果表明:3种有机酸对根际环境沉淀物中Fe、Mn的释放均产生不同程度的影响,相同浓度下的有机酸对Fe的影响顺序为:柠檬酸苹果酸草酸,对Mn的影响顺序为:柠檬酸草酸苹果酸。随着有机酸浓度的增加,沉淀物中Fe、Mn的释放量逐渐增加,且Fe的释放量大于Mn。形态分析结果表明,在有机酸参与前沉淀物中Fe、Mn主要以可还原态形式存在,当添加3种不同浓度的有机酸后,沉淀物中的可还原态Fe、Mn极不稳定,易向可交换态发生转变,而残渣态与可氧化态则较为稳定,说明沉淀物中残渣态与可氧化态的Fe、Mn在人工湿地中是Fe、Mn去除的重要途径。
[Abstract]:In order to study the effect of plant root exudates on the activity of Fe,Mn in rhizosphere sediment in (acid mine drainage,AMD system, the stability and reliability of AMD fixation in constructed wetland were evaluated. The effects of citric acid, malic acid and oxalic acid in plant root exudates on the release and morphology of Fe,Mn in sediment were simulated. The results showed that the three kinds of organic acids had different effects on the release of Fe,Mn in rhizosphere sediments. The order of the effects of organic acids at the same concentration on Fe was as follows: malic acid citrate oxalic acid. The order of influence on Mn is citrate oxalate malic acid. With the increase of organic acid concentration, the release of Fe,Mn in precipitate increased gradually, and the release of Fe was greater than that of Mn.. The results of speciation analysis showed that Fe,Mn existed mainly in the form of reducible state in the precipitate before organic acid participation. When three different concentrations of organic acids were added, the Fe,Mn in the precipitate was unstable and easy to change to the exchangeable state. The residual state and oxidizable state are more stable, indicating that the residual and oxidizable Fe,Mn in the sediment is an important way to remove Fe,Mn in the constructed wetland.
【作者单位】：贵州大学资源与环境工程学院;贵州大学应用生态研究所;贵州大学新农村研究院;
【基金】：贵州省教育厅自然科学研究项目[黔教合KY字(2016)011];贵州省教育厅研究生教育创新计划项目[黔教研合GZZ字(2016)07]
【分类号】：X751

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