Silver(I) Binding Properties of Organic Soil Materials Are Different from Those of Isolated Humic Substances
2016 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 50, no 14, 7453-7460 p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2016. Vol. 50, no 14, 7453-7460 p.
X-Ray-Absorption, Soft Acids, Coordination Chemistry, Cation-Binding, Ion-Binding, Bases Hsab, Matter, Speciation, Water, Complexation
IdentifiersURN: urn:nbn:se:kth:diva-191752DOI: 10.1021/acs.est.6b00970ISI: 000380295700021ScopusID: 2-s2.0-84978791283OAI: oai:DiVA.org:kth-191752DiVA: diva2:970440
FunderSwedish Research CouncilKnut and Alice Wallenberg FoundationThe Crafoord Foundation
QC 201609132016-09-132016-09-022016-09-13Bibliographically approved