Effects of competing anions and iron bioreduction on arsenic desorption

Silva, Juscimar, Vargas de Mello, Jaime Wilson, Gasparon, Massimo and Pereira Abrahao, Walter Antonio (2012) Effects of competing anions and iron bioreduction on arsenic desorption. Water Air and Soil Pollution, 223 9: 5707-5717. doi:10.1007/s11270-012-1308-0

Author Silva, Juscimar
Vargas de Mello, Jaime Wilson
Gasparon, Massimo
Pereira Abrahao, Walter Antonio
Title Effects of competing anions and iron bioreduction on arsenic desorption
Journal name Water Air and Soil Pollution   Check publisher's open access policy
ISSN 0049-6979
Publication date 2012-11
Sub-type Article (original research)
DOI 10.1007/s11270-012-1308-0
Volume 223
Issue 9
Start page 5707
End page 5717
Total pages 11
Place of publication Dordrecht, Netherlands
Publisher Springer Netherlands
Collection year 2013
Language eng
Abstract Dissimilatory iron-reducing bacteria play a fundamental role in catalysing the redox transformations that ultimately control the mobility of As in anoxic environments, a process also controlled by the presence of competing anions. In this study, we investigated the decoupling of As from loaded Al and Fe (hydr)oxides by competing anions in the presence of iron-reducing bacteria. Hematite, goethite, ferrihydrite, gibbsite and three aluminium-substituted goethites (AlGts) were synthesised and loaded with arsenate, followed by anaerobic incubation with different phosphate or carbonate-containing media in the presence of catalytic iron-reducing bacteria. Soluble Al, As, Fe and P contents were measured in aliquots by inductively coupled plasma optical emission spectrometry following periodical sampling. Shewanella putrefaciens cells were able to utilise both noncrystalline and crystalline Fe (hydr)oxides as electron acceptors, releasing Fe and As into solution. Phosphate and carbonate affected the Fe bioreduction, probably due to the precipitation of metastable mineral phases and also to phosphate-induced stabilisation on the hydroxide surfaces. Phosphate precipitation acted as a sink for As, thus limiting its mobilisation. The highest fraction of desorbed As by phosphate was observed for gibbsite, followed by AlGts. Similarly, gibbsite showed significant amounts of arsenate displaced by carbonate. In spite of its low crystallinity, ferrihydrite was the most efficient compound in retaining arsenate, possibly due to As co-precipitation. This study provides new insight into the management of As-contaminated soils and sediments containing Algoethites and gibbsite, where the Fe activity may be too low to co-precipitate As-bearing vivianite. Thus, the dynamics of As(V) in flooded soils are significant in agriculture and environmental management.
Keyword Arsenic contamination
Al-substituted goethites
Redox stability
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes Published online: 18 September 2012.

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Earth Sciences Publications
Official 2013 Collection
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Citation counts: TR Web of Science Citation Count  Cited 3 times in Thomson Reuters Web of Science Article | Citations
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