The reductive dissolution of jarosites by Shewanella putrefaciens: A potential pathway for metal mobilization in the environment?
THURSDAY, DECEMBER 15, 2011 - 3:30 PM TO 4:30 PM IN EIT 3142 AT THE UNIVERSITY OF WATERLOO
Abstract:
Large quantities of jarosites (MFe3(SO4)2(OH)6) are produced in the zinc industry to remove impurities during the extraction process and may contain toxic metals such as lead (Pb), thallium (Tl) and arsenic (As). Jarositic wastes are often confined to capped tailings ponds, thereby, creating the potential for anaerobic reductive dissolution by microbial populations. However, despite the environmental relevance of jarosite minerals, few studies have evaluated the abiotic or biotic dissolution of jarosites under anaerobic circumneutral conditions. Batch experiments were conducted to examine the influence of a model metal reducing bacterium, Shewanella putrefaciens CN32, on the potential mobilization of Tl, As and Pb during the reductive dissolution of a variety of synthetic and natural jarosites. I will use the results from these studies to examine the role of metal biogeochemistry (i.e. Fe, Tl, Pb and As) and mineral structure on the susceptibility of jarosites to reductive dissolution by S. putrefaciens.