Effective removal of trace thallium from surface water by nanosized manganese dioxide enhanced quartz sand filtration
Effective removal of trace thallium from surface water by nanosized manganese dioxide enhanced quartz sand filtration
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纳米二氧化锰强化石英砂过滤有效去除地表水中微量铊
DOI：
10.1016/j.chemosphere.2017.09.039
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发表时间：
2017-12-01
期刊：
影响因子：
8.8
通讯作者：
Wang, Yaan
中科院分区：
文献类型：
--
作者：
Huangfu, Xiaoliu;Ma, Chengxue;Wang, Yaan
铊（Tl）由于其即使在极低浓度下也具有高毒性以及其在人体和其他生物体中显著积累的趋势而引起广泛关注。迫切需要开发有效的策略来从饮用水中去除痕量Tl。在这项研究中，去除痕量铊（0.5 μ g L-1），通过传统的石英砂过滤增强纳米二氧化锰（nMnO（2））已被调查使用典型的地表水从中国东北地区。结果表明，nMnO（2）强化石英砂过滤可有效去除水中痕量Tl（I）和Tl（III），其机理为：水基质中的nMnO（2）和石英砂表面的nMnO（2）对Tl（I）和Tl（III）的吸附。与残余Tl（I）相比，Tl（III）-HA复合物可能导致流出物中较高的残余Tl（III）。竞争性的Ca ~（2+）阳离子在一定程度上抑制了Tl的去除，因为Ca ~（2+）离子会占据Tl在nMnO（2）上的吸附位点。此外，高浓度的HA（10 mgTOC L-1），其显著地与nMnO（2）络合并溶解nMnO（2）（超过78%），导致更高的残留Tl（I）和Tl（III）。Tl（III）-HA复合物也可能在一定程度上增强Tl（III）的渗透。此外，较高的pH水平可以增强从地表水中去除痕量Tl。最后，在离心后观察到残余Tl的轻微增加，随后流出物中的Tl浓度再次降低至“稳定”状态。这里获得的知识可能会提供一个潜在的策略，饮用水处理厂受到威胁的痕量铊。(C)2017由Elsevier Ltd.出版
Thallium (Tl) has drawn wide concern due to its high toxicity even at extremely low concentrations, as well as its tendency for significant accumulation in the human body and other organisms. The need to develop effective strategies for trace Tl removal from drinking water is urgent. In this study, the removal of trace Tl (0.5 mu g L-1) by conventional quartz sand filtration enhanced by nanosized manganese dioxide (nMnO(2)) has been investigated using typical surface water obtained from northeast China. The results indicate that nMnO(2) enhanced quartz sand filtration could remove trace Tl(I) and Tl(III) efficiently through the adsorption of Tl onto nMnO(2) added to a water matrix and onto nMnO(2) attached on quartz sand surfaces. Tl(III)-HA complexes might be responsible for higher residual Tl(III) in the effluent compared to residual Tl(I). Competitive Ca2+ cations inhibit Tl removal to a certain extent because the Ca2+ ions will occupy the Tl adsorption site on nMnO(2). Moreover, high concentrations of HA (10 mgTOC L-1), which notably complexes with and dissolves nMnO(2) (more than 78%), resulted in higher residual Tl(I) and Tl(III). Tl(III)-HA complexes might also enhance Tl(III) penetration to a certain extent. Additionally, a higher pH level could enhance the removal of trace Tl from surface water. Finally, a slight increase of residual Tl was observed after backwash, followed by the reduction of the Tl concentration in the effluent to a "steady" state again. The knowledge obtained here may provide a potential strategy for drinking water treatment plants threatened by trace Tl. (C) 2017 Published by Elsevier Ltd.