Sorption Characteristics of Pentachlorophenol Onto Fe Oxides Extracted from the Surficial Sediments

The sorption characteristics of pentachlorophenol (PCP) onto the surficial sediments and their main component: Fe oxides were investigated using the selective extraction procedures and the additional model. The results show that the maximum adsorption of PCP onto the sediments extracted by H₂O₂ decreased, and those of PCP treated by NH₂OHHCl, H₂C₂O₄- (NH₄)₂C₂O₄ or H₂O₂-NH₂OH-HC1 increased, respectively, this indicates that the Fe oxides is the main site for PCP sorption onto the surficial sediments, and Mn oxides inhibit PCP adsorption. The analysis of the adsorption data via the additional model shows that the contribution of Fe oxides was approximately 6 orders of magnitude than that of organic materials or residues to PCP adsorption, and Mn oxides in the sediments directly or indirectly restrained the interaction of PCP with Fe oxides in the sediments. PCP adsorption onto Fe oxides in the surficial sediments, which was estimated through the additional model, was confirmed by PCP adsorption onto the Fe oxides extracted selectively from the surficial sediments, that is, the additional model could be employed to estimate the relative contribution of Fe, Mn oxides and organic matter to PCP adsorption onto the surficial sediments in aquatic environments, although there are interactions between Fe oxides and Mn oxides for PCP adsorption onto the surficial sediments.