Binding Sites and Conditional Complexation Constants of Natural Organic Matter with Hg~(2+) and CH_3Hg~+

摘要

This paper provides evidence for the presence of reduced sulfur sites in NOM and for the binding of mercury species primarily with reduced sulfur sites at environmentally relevant Hg concentrations. X-ray absorption near edge spectroscopy (XANES) and x-ray absorption fine structure spectroscopy (XAFS), respectively, were used for these studies. Using competitive ligand techniques, we determined conditional complexation constants for mercuric ion (Hg~(2+)) and methylmercuric ion MeHg~) with NOM extracted from soil and surface waters.