Zinc immobilization by zerovalent Fe: surface chemistry and mineralogy and reaction products
2003 (English)In: Mineralogical magazine, ISSN 0026-461X, E-ISSN 1471-8022, Vol. 67, no 6, 1285-1298 p.Article in journal (Refereed) Published
In bioreactor systems for the treatment of metal-contaminated water, pretreatment with zerovalent Fe can be exploited for oxygen consumption and H-2 Production. In this study, a column experiment is used to investigate the changes in surface chemistry and solid phase products that result from the reaction of a Zn-sulphate-lactate solution with zerovalent Fe filings. The results of this study indicate that zerovalent Fe is very effective in immobilizing dissolved Zn with a porewater residence time of 1.3-3.1 days. A combination of X-ray diffractometry, X-ray photoelectron spectroscopy, and mineral equilibria calculations indicates that Zn precipitates as Zn(OH)(2) and zincite at PH 9-10. At PH approximate to 6, Zn primarily adsorbs to abundant ferric oxyhydroxides, although incorporation in green rust is also considered. During the course of the experiment, the surface mineralogy changes from magnetite-lepidocrocite-goethite to green rust-akaganeite-goethite. The results suggest that the zerovalent Fe surface becomes passivated by a surface film of ferric oxyhydroxides, green rust and organic material, so that the rate of electron transfer and proton consuming reactions (i.e. oxygen consumption, H-2 generation) declines, resulting in a decrease in solution PH.
Place, publisher, year, edition, pages
2003. Vol. 67, no 6, 1285-1298 p.
Oceanography, Hydrology, Water Resources
IdentifiersURN: urn:nbn:se:uu:diva-47156DOI: 10.1180/0026461036760165OAI: oai:DiVA.org:uu-47156DiVA: diva2:75063