Effect of pedogenic iron-oxyhydroxide removal on the metal sorption by soil clay minerals

Abstract Purpose The close association of Fe-oxyhydroxides and clay minerals might influence the sorption properties these components. We aimed to study effect removing pedogenic on Cd, Cu, Pb, Zn by mineral particles in soils with contrasting pH. Methods Competitive batch experiments before after Fe-oxyhydroxide extraction were carried out together direct analysis metal individual ferrihydrite, smectite, illite/smectite TEM. Results Ferrihydrite was a more effective sorbent than minerals, although its removal resulted decreased only for Zn. Ferrhydrite coating blocked metals’ access certain sites surfaces, which accessible Pb as most efficient competitor coating. This observation remarkable smectite alkaline soil. Mineral surfaces sorbed higher Cu concentrations Cd despite former lower bulk sorption. Thus, organic precipitation contributed Cd’s retention greater extent structural Fe also promoted both soils. Conclusion Removal iron-oxyhydroxide coatings from soil affects selectively. Direct enables us gain in-depth insight into minerals’ role this process.