Silver(I) Binding Properties of Organic Soil Materials Are Different from Those of Isolated Humic Substances.
The solubility of silver(I) in many soils is controlled by complexation reactions with organic matter. In this work we have compared the ability of isolated humic and fulvic acids to bind silver(I) with that of mor and peat materials. One new data set for Suwannee River Fulvic Acid was produced, which was consistent with published data sets for isolated fulvic and humic acids. The ability of soil materials to bind silver(I) was studied as a function of pH in the range 2.5-5.0, at a wide range of silver(I)-to-soil ratios (10(-4.2) - 10(-1.9) mol kg(-1)). By calibrating the Stockholm Humic Model on the humic and fulvic acids data sets, we showed that binding of silver(I) to both types of soil materials was much stronger (up to 2 orders of magnitude) than predicted from the silver(I) binding properties of the isolated humic materials. Thus, the approach taken for many other metals, that is, to model solubility in soils by using metal and proton binding parameters derived from isolated humic and fulvic acids, cannot be used for silver(I). One possible explanation for the discrepancy could be that silver(I) predominately interacted with various biomolecules in the soil samples, instead of humic- and fulvic-acid type materials.
Department of Soil and Environment, Swedish University of Agricultural Sciences , P.O. Box 7014, SE-750 07 Uppsala, Sweden.|Swedish Geotechnical Institute , Kornhamnstorg 61, SE-111 27 Stockholm, Sweden.
Dan
D
B Kleja
Department of Soil and Environment, Swedish University of Agricultural Sciences , P.O. Box 7014, SE-750 07 Uppsala, Sweden.|Kyoto Institute of Technology , Matsugasaki Sakyo-ku, Kyoto 606-8585, Japan.
Satomi
S
Nakata
Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences , P.O.-Box 7015, SE 750 07, Uppsala, Sweden.
Ingmar
I
Persson
Department of Soil and Environment, Swedish University of Agricultural Sciences , P.O. Box 7014, SE-750 07 Uppsala, Sweden.|Department of Land and Water Resources Engineering, KTH (Royal Institute of Technology) , SE-100 44 Stockholm, Sweden.
Jon Petter
JP
Gustafsson
D001578:Benzopyrans / Q000737:chemistry; D006812:Humic Substances; D012834:Silver; D012987:Soil; D012989:Soil Pollutants; D012995:Solubility
D001578:Benzopyrans; D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D012834:Silver