胡敏酸对不同矿物结合汞的还原作用  

Effects of humic acids on the reduction of different mineral bound Hg

作　　者：刘丽琼[1] 江韬[1,2] 魏世强[1,2] 张艳敏[1] 李雪梅[1] 

机构地区：[1]西南大学资源环境学院,环境科学与工程系,重庆400715 [2]重庆市农业资源与环境研究重点实验室,重庆400715

出　　处：《中国环境科学》2011年第12期1998-2004,共7页China Environmental Science

基　　金：国家自然科学基金资金项目(40971147/D010503);西南大学研究生科技创新基金项目(ky2010013);中央高校基本科研业务费专项(XDJK2009C053)

摘　　要：采用扩散吸收法探讨了胡敏酸对不同矿物结合态汞的还原作用及光照的影响.结果表明:两种胡敏酸(TJ和SH)对碳酸钙、氧化锰和赤铁矿结合态汞均具有明显的还原作用,还原动力学过程表现为先递增后渐趋平稳,可用双常数方程、Elovich方程和指数方程拟合;还原容量与吸持矿物类型有关,平均还原率大小为:CaCO3-Hg(0.67%)>Fe2O3-Hg(0.42%)>MnO2-Hg(0.19%);光照对胡敏酸还原矿物结合态汞具有强化效应,以CaCO3-Hg和Fe2O3-Hg光强化效果最明显,平均还原率较遮光时高出0.10%以上;两种胡敏酸(SH和TJ)对矿物结合态汞的还原能力存在差异(P<0.1),遮光条件下SH的还原能力均高于TJ,而光照条件下TJ对CaCO3-Hg的还原能力大于SH,对MnO2-Hg的还原则无显著差异,意味着SH的光敏性低于TJ,可能与不同胡敏酸氧化还原活性基团含量和芳香化程度(E4/E6)不同有关.Diffusion-absorption method was used to investigate the effect of humic acid （HA） on different types of mineral bound mercury, especially under light condition. The results suggested that two HA （TJ and SH） could reduce CaCO3-Hg, MnO2-Hg and Fe2O3-Hg significantly, and the trend of increasing initially then stabilizing was observed in kinetics experiment. In addition, two constants from Elovich and exponential equation were well fitted with the kinetics process, meanwhile reduction capacities of HA varied due to mineral type, indicating that the order of average reduction rate was as follows： CaCO3-Hg（0.67%）〉Fe2O3-Hg（0.42%）〉MnO2-Hg（0.19%）. Furthermore, light could enhance the reduction of humic acid on mineral bound mercury, showing that the greatest significance in CaCO3-Hg and Fe2O3-Hg, and the average reduction rate was 0.10% higher in comparison with in darkness condition. The reduction capacities of two humic acids （SH and TJ） were different （P〈0.1） significantly, and SH reduction capacity all was greater than TJ in darkness, except that TJ was greater than SH in reduction of CaCO3-Hg under light condition, however in the same light environment, the reduction of MnO2-Hg between SH and TJ was not significantly different, which maybe explained through differences of free radical groups and aromatic degree （E4/E6） resulted in various reduction capacity.

关 键 词：胡敏酸 矿物结合汞 还原作用 

分 类 号：X53[环境科学与工程—环境工程]