Adsorption of trace elements on iron hydroxides: Isotopic fractionation and microbial effect

Abstract

Iron hydroxides are nanoparitcles found in verious environment, which affects greatly the environmental behavior of trace elements due to its reactive nature and large surface area. There are a number of researches on the interaction between trace elements and iron hydroxides. In this presentation, some new aspects of the interction is given such as isotopic fractionation of trace elements during their adsorption on iron hyrdoxides and also microbial effect on the adsrotpion. For Mo isotopic fractionation, it was found that lighter isotope is enriched in manganese oxdies, but not in ferrihydrite. These differences can be explained by their different adsorbed species on the two minerals: inner-sphere complex on manganese oxides, but outer-sphere complex on ferrihdyrite.