Leaching and accumulation of trace elements in sulfate reducing granular sludge under concomitant thermophilic and low pH conditions
KAUST DepartmentBiological and Environmental Sciences and Engineering (BESE) Division
Environmental Science and Engineering Program
Water Desalination and Reuse Research Center (WDRC)
Permanent link to this recordhttp://hdl.handle.net/10754/565989
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AbstractThe leaching and/or accumulation of trace elements in sulfate reducing granular sludge systems was investigated. Two thermophilic up-flow anaerobic sludge bed (UASB) reactors operated at pH 5 were fed with sucrose (4gCODl reactor -1d -1) and sulfate at different COD/SO 4 2- ratios. During the start-up of such acidogenic systems, an initial leaching of trace elements from the inoculum sludge occurred regardless of trace elements supplementation in the reactor influent. The granular sludge maintained the physical structure despite high Fe leaching. After start-up and nonetheless the acidic conditions, Co, Ni, Cu, Zn, Mo and Se were retained or accumulated by the sludge when added. Particularly, Ni and Co accumulated in the carbonates and exchangeable fractions ensuring potential bioavailability. Otherwise, the initial stock in the inoculum sludge sufficed to operate the process for nearly 1year without supplementation of trace elements and no significant sludge wash-out occurred. © 2012 Elsevier Ltd.
CitationGonzalez-Gil, G., Lopes, S. I. C., Saikaly, P. E., & Lens, P. N. L. (2012). Leaching and accumulation of trace elements in sulfate reducing granular sludge under concomitant thermophilic and low pH conditions. Bioresource Technology, 126, 238–246. doi:10.1016/j.biortech.2012.09.044
SponsorsThis work was partially funded by a Ph.D. grant from the Fundacao para a Ciencia e Tecnologia, Portugal (SFRH/BD/9268/2002) and by a Global Collaborative Research award from King Abdullah University of Science and Technology, Saudi Arabia (GRP-CF-2011-13-P). We thank Ricardo Sampaio for contributing to the operation of the bioreactors.