Biologically mediated mobilization of arsenic from granular ferric hydroxide in anaerobic columns fed landfill leachate

• Published in: Biotechnology and bioengineering Vol. 101; no. 6; pp. 1205 - 1213
• Main Authors: Cortinas, Irail, Sierra-Alvarez, Reyes, Field, Jim A
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.12.2008; Wiley; Wiley Subscription Services, Inc
• Subjects: Anaerobiosis; Arsenic; Arsenic - metabolism; arsenic release; Bioassays; Biological and medical sciences; Bioreactors; Bioremediation; Biotechnology; dissimilatory arsenate reduction; dissimilatory iron reduction; Drinking water; Ferric Compounds - metabolism; Fundamental and applied biological sciences. Psychology; Iron; iron biomineralization; Landfill; Landfills; Leachates; magnetite; Metabolites; Mineralogy; Waste disposal sites; Water Pollutants, Chemical - metabolism; Water treatment; Waste dumping; Arsenic; dissimilatory iron reduction; Biomineralization; Iron; dissimilatory arsenate reduction; iron biomineralization; Reduction; Magnetite; Anaerobe; Mineralization; arsenic release; Leachate; Release
• ISSN: 0006-3592; 1097-0290; 1097-0290
• DOI: 10.1002/bit.22021

To gain insight on the fate of arsenic (As) from drinking water treatment residuals in landfills, the mobilization of arsenate adsorbed onto granular ferric hydroxide (GFH) was studied in continuous anaerobic columns fed with a synthetic landfill leachate. The release of As was compared in biologically active and abiotic columns. More than 150 days of incubation were required before noteworthy As release occurred. After 400 days of operation, 19% of the As was mobilized as identified species in the biologically active column, which was 25.5-fold greater than that of the abiotic column. Fine colloids accounted for up to 81% of the As released. Arsenite was the predominant species identified in filtered (0.45 μm) effluent samples. Dimethylarsinic acid and monomethylarsonic acid were also observed as metabolites. During column operation, approximately 30% of the iron (hydr)oxide mass was lost and most of the mass loss was attributed to changes in iron mineralogy that could be demonstrated in a batch bioassay. The results indicate that As-laden GFH residuals from drinking water treatment are subject to mobilization in municipal landfills and that biologically mediated changes in the iron mineralogy may play an important role in the mobilization mechanism. Biotechnol. Bioeng. 2008;101: 1205-1213.