Effects of Oxyanions on the EDTA-Promoted Dissolution of Goethite

Autor:	Matthew J. Eick, Jillian L. Campbell
Rok vydání:	2002
Předmět:	Oxide minerals Goethite Ligand Chemistry Inorganic chemistry Soil Science Oxyanion Molybdate Phosphate chemistry.chemical_compound Adsorption Geochemistry and Petrology visual_art Earth and Planetary Sciences (miscellaneous) visual_art.visual_art_medium Dissolution Water Science and Technology
Zdroj:	Clays and Clay Minerals. 50:336-341
ISSN:	0009-8604
DOI:	10.1346/00098600260358094
Popis:	Organic ligands, such as EDTA, accelerate the dissolution of silicate and oxide minerals. In natural systems, oxyanions can compete with organic ligands for mineral surface sites thereby affecting ligand-promoted dissolution rates, either enhancing or inhibiting dissolution, depending upon pH. The influence of selenite, molybdate and phosphate on the EDTA-promoted dissolution of goethite has been examined and a mechanism proposed for the observed differences in dissolution rates over a pH range of 4–8. We propose that the surface complex formed by EDTA is the controlling factor for the observed dissolution rate, with mononuclear complexes accelerating dissolution compared to bi- or multinuclear complexes. Dissolution results from our experiments suggest that EDTA forms multinuclear complexes at pH values ⩾6 and mononuclear complexes at pH values
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::e33c4e16f97f93347e2269dec944437e https://doi.org/10.1346/00098600260358094 Zobrazit plný text záznamu Full text from SpringerLink