文献类型：期刊文献

英文题名：Oxidation of Cr(III) on birnessite surfaces: The effect of goethite and kaolinite

作者：Zhong, Laiyuan[1];Yang, Jiewen[1,3];Liu, Liming[2];Xing, Baoshan[3]

机构：[1]Guangdong Ocean Univ, Coll Agr, Dept Resources & Environm Sci, Zhanjiang 524088, Peoples R China;[2]China Agr Univ, Coll Resources & Environm Sci, Dept Land Resources Management, Beijing 100193, Peoples R China;[3]Univ Massachusetts, Stockbridge Sch Agr, Amherst, MA 01003 USA

年份：2015

卷号：37

起止页码：8

外文期刊名：JOURNAL OF ENVIRONMENTAL SCIENCES

收录：SCI-EXPANDED(收录号：WOS:000365931900002)、、EI(收录号：20154701564787)、Scopus(收录号：2-s2.0-84946924360)、WOS

基金：This work was supported by the National Natural Science Foundation of China (Nos. 41130526, 41101214 and 41371316) and the USDA NIFA Hatch Program (No. MAS00475).

语种：英文

外文关键词：Cr(III) oxidation; Birnssite; Goethite; Kaolinite

外文摘要：Oxidation of Cr(III) by manganese oxides may pose a potential threat to environments due to the formation of toxic Cr(VI) species. At present, it was still unclear whether the extent of Cr(III) oxidation and fate of Cr(VI) would be changed when manganese oxides co-exist with other minerals, the case commonly occurring in soils. This study investigated the influence of goethite and kaolinite on Cr(III) oxidation by birnessite under acidic pH condition (pH 3.5) and background electrolyte of 0.01 mol/L NaCl. Goethite was found not to affect Cr(III) oxidation, which was interpreted as the result of overwhelming adsorption of cationic Cr(III) onto the negatively-charged birnessite (point of zero charge (pzq)<3.0) rather than the positively-charged goethite (PZC = 8.8). However, more Cr(VI) would be retained by the surface with the increase in addition of goethite because of its strong ability on adsorption of Cr(VI) at low pH. Moreover, either Cr(III) oxidation or distribution of the generated Cr(VI) between the solid and solution phases was not affected by kaolinite (PZC < 3.0), indicating its low affinity for Cr species. Reactions occurring in the present mixed systems were suggested, which could be partly representative of those in the soils and further indicates that the mobility and risk of Cr(VI) would be decreased if goethite was present. (C) 2015 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.