Abiotic oxidation of Mn(II) induced oxidation and mobilization of As(III) in the presence of magnetite and hematite
Abiotic oxidation of Mn(II) induced oxidation and mobilization of As(III) in the presence of magnetite and hematite
复制标题
磁铁矿和赤铁矿存在下 Mn(II) 的非生物氧化诱导 As(III) 的氧化和移动
DOI：
10.1016/j.jhazmat.2013.03.022
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发表时间：
2013-06-15
影响因子：
13.6
通讯作者：
Han, Xu
中科院分区：
文献类型：
--
作者：
Ren, Hai-Tao;Jia, Shao-Yi;Han, Xu
锰（氢）氧化物在自然条件下是介导As（III）转化为As（V）的强氧化剂，然而，在pH 7.0-9.0范围内Mn（II）的存在对As（III）氧化的影响至今未见报道。在这项研究中，非生物氧化锰（II）的非晶锰（III，IV）（氢）氧化物（MnOx）磁铁矿和赤铁矿被证实，和新形成的MnOx的命运的影响As（III）进行了研究。Mn（II）的加入，使As（III）在高pH下被氧化为As（V），并使吸附态As（III）和As（V）在赤铁矿体系中被活化。高产量的溶解As（V）和显着的动员As（III）的赤铁矿悬浮液（总砷为18.96毫克L-1后，60小时，pH值8.62），同时添加Mn（II）和As（III），甚至更显着，而磁铁矿表现出较高的容量为保留的As（III）和As（V）。因此，可以推断，新形成的MnOx铁氧化物可以氧化溶解和吸附的As（III）到As（V）。此外，在高pH值下形成的MnOx会占据之前被吸附的As（III）占据的吸附位点，然后将一部分吸附的As（III）动员到溶液中。本研究表明，通过非生物氧化铁氧化物形成的MnOx在水环境中溶解和吸附的As（III）的氧化和动员中起着重要的作用。(C)2013爱思唯尔有限公司版权所有。
Manganese (hydr)oxides are powerful oxidants mediating the transformation of As(III) to As(V) under natural conditions, however, the presence of Mn(II) on the oxidation of As(III) in the pH range of 7.0-9.0 has not been reported so far. In this study, abiotic oxidation of Mn(II) to amorphous Mn(III, IV) (hydr)oxides (MnOx) on magnetite and hematite was confirmed, and the impact of newly formed MnOx on the fate of As(III) was investigated. With the addition of Mn(II) into As(III)-preloaded systems, the dissolved and the adsorbed As(III) was oxidized to As(V) at high pH, and Mn(II) mobilized the adsorbed As(III) and As(V) in hematite system. High production of dissolved As(V) and significant mobilization of As(III) were even more significant in hematite suspension (total As was 18.96 mg L-1 after 60 h at pH 8.62) with simultaneous addition of Mn(II) and As(III), while magnetite showed a higher capacity for the retention of As(III) and As(V). It could therefore be deduced that the newly formed MnOx on iron oxides could oxidize the dissolved and the adsorbed As(III) to As(V). In addition, the MnOx formed at high pH would take up the sorption sites previously occupied by the adsorbed As(III), and then mobilized a fraction of the adsorbed As(III) into solution. The present study reveals that MnOx formed via abiotic oxidation on iron oxides plays an important role in the oxidation and mobilization of both dissolved and adsorbed As(III) in aquatic environment. (C) 2013 Elsevier B.V. All rights reserved.