Scavenging of Cd through Fe/Mn oxides within natural surface coatings

作     者：LI Yu HUANG Guo-he ZHANG Bai-yu GUO Shu-hai 

作者机构：Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China Department of Environmental Science College of Environment and Resources Jilin University Changchun 130012 China Environmental Systems Engineering Program Faculty of Engineering University of Regina Regina SK S4S 0A2 Canada 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2006年第18卷第6期

页      面：1199-1203页

核心收录：

学科分类：083001[工学-环境科学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 08[工学] 

基　　金：The National Basic Research Program (973) of China (No. 2004CB3418501) 

主　　题：cadmium scavenging natural surface coatings selective extraction iron oxides manganese oxides 

摘      要：The dynamics of Cd scavenging from solutions by Fe/Mn oxides in natural surface coatings （NSCs） was investigated under laboratory conditions. Selective extraction methods were employed to estimate the contributions of Fe/Mn oxides, where hydroxylamine hydrochloride （0.01 mol/L NH2OH-HCl ＋ 0.01 mol/L HNO3）, sodium dithionite （0.4 mol/L Na2S2O4） and nitric acid （10% HNO3） were used as extraction reagents. The Cd scavenging was accomplished with developing periods of the NSCs （totally 21 data sets）. The resulting process dynamics fitted well to the Elovich equation, demonstrating that the amount of Cd scavenged was proportional to the increments of Fe/Mn oxides that were accumulated in the NSCs. The amount of Cd bound to Fe oxides （MCdFe） and Mn oxides （MCdMn） could be quantified by solving two equations based on the properties of two extraction reagents. The amount of Cd scavenged by Fe/Mn oxides could also be estimated using MCdFe and MCdMn divided by the total amounts of Fe and Mn oxides in the NSCs, respectively. The results indicated that the Cd scavenging by Fe/Mn oxides was dominated by Fe oxides, with less roles attributed to Mn oxides. The estimated levels of Cd scavenging through Fe and Mn oxides agreed well with those predicted through additive-adsorption and linear-regression models.