文献类型：期刊文献

英文题名：Reduction of Cr(VI) by malic acid in aqueous Fe-rich soil suspensions

作者：Zhong, Laiyuan[1];Yang, Jiewen[1,2]

机构：[1]Guangdong Ocean Univ, Dept Resources & Environm Sci, Coll Agr, Zhanjiang 524088, Peoples R China;[2]Chinese Acad Sci, Inst Soil Sci, State Key Lab Soil & Sustainable Agr, Nanjing 210008, Peoples R China

年份：2012

卷号：86

期号：10

起止页码：973

外文期刊名：CHEMOSPHERE

收录：SCI-EXPANDED(收录号：WOS:000302277600001)、、EI(收录号：20120614749687)、Scopus(收录号：2-s2.0-84856558446)、WOS

基金：This work was jointly funded by the National Science Foundation of China (Grant Nos. 40871156, 41101214) and the Foundation of State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences (Grant No. 081000040).

语种：英文

外文关键词：Cr(VI) reduction; Organic acids; Catalysis; Soil Fe-oxides

外文摘要：Detoxification of Cr(VI) through reduction by organic reductants has been regarded as an effective way for remediation of Cr(VI)-polluted soils. However, such remediation strategy would be limited in practical applications due to the low Cr(VI) reduction rate. In this study, the catalytic effect of two Fe-rich soils (Ultisol and Oxisol) on Cr(VI) reduction by malic acid was evaluated. As the results shown, the two soils could obviously accelerate the reduction of Cr(VI) by malic acid at low pH conditions, while such catalytic effect was gradually suppressed as the increase in pH. After reaction for 48 h at pH 3.2, Oxalic acid was found in the supernatant of Ultisol, suggesting the oxidization of hydroxyl in malic acid to carboxyl and breakage of the bond between C-2 and C-3. It was also found that the catalytic reactivity of Ultisol was more significant than that of Oxisol, which could be partly attributed to the fact that the amount of Fe(II) released from the reductive dissolution of Ultisol by malic acid was larger than that of Oxisol. With addition of AI(III), the catalytic effect from Ultisol was inhibited across the pH range examined. On the contrary, the presence of Cu(II) would increase the catalytic effect of Ultisol, which was more pronounced with the increase in pH. This study proposed a potential way for elimination of the environmental risks posed by the Cr(VI) contamination by use of the natural soil surfaces to catalyze Cr(VI) reduction by the organic reductant such as malic acid, a kind of organic reductant originating from soil organic decomposition process or plant excretion. (C) 2011 Elsevier Ltd. All rights reserved.