Arsenic remediation by formation of arsenic sulfide minerals in a continuous anaerobic bioreactor
Moore, Sarah E
Root, Robert A
Field, James A
AffiliationUniv Arizona, Dept Chem & Environm Engn
Univ Arizona, Dept Soil Water & Environm Sci
MetadataShow full item record
CitationRodriguez‐Freire, L. , Moore, S. E., Sierra‐Alvarez, R. , Root, R. A., Chorover, J. and Field, J. A. (2016), Arsenic remediation by formation of arsenic sulfide minerals in a continuous anaerobic bioreactor. Biotechnol. Bioeng., 113: 522-530. doi:10.1002/bit.25825
JournalBIOTECHNOLOGY AND BIOENGINEERING
Rights© 2015 Wiley Periodicals, Inc.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractArsenic (As) is a highly toxic metalloid that has been identified at high concentrations in groundwater in certain locations around the world. Concurrent microbial reduction of arsenate (AsV) and sulfate (SO42-) can result in the formation of poorly soluble arsenic sulfide minerals (ASM). The objective of this research was to study As biomineralization in a minimal iron environment for the bioremediation of As-contaminated groundwater using simultaneous AsV and SO42- reduction. A continuous-flow anaerobic bioreactor was maintained at slightly acidic pH (6.25-6.50) and fed with AsV and SO42-, utilizing ethanol as an electron donor for over 250 d. A second bioreactor running under the same conditions but lacking SO42- was operated as a control to study the fate of As (without S). The reactor fed with SO42- removed an average 91.2% of the total soluble As at volumetric rates up to 2.9 mg As/(L∙h), while less than 5% removal was observed in the control bioreactor. Soluble S removal occurred with an S to As molar ratio of 1.2, suggesting the formation of a mixture of orpiment- (As2S3) and realgar-like (AsS) solid phases. Solid phase characterization using K-edge X-Ray absorption spectroscopy confirmed the formation of a mixture of As2S3 and AsS. These results indicate that a bioremediation process relying on the addition of a simple, low-cost electron donor offers potential to promote the removal of As from groundwater with naturally occurring or added sulfate by precipitation of ASM.
Note12 month embargo; published online: 2 September 2015
VersionFinal accepted manuscript