Arsenic mitigation in paddy soils by using microbial fuel cells

Williamson Gustave, Zhao Feng Yuan, Raju Sekar, Hu Cheng Chang, Jun Zhang, Mona Wells, Yu Xiang Ren, Zheng Chen*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

40 Citations (Scopus)

Abstract

Arsenic (As) behavior in paddy soils couples with the redox process of iron (Fe) minerals. When soil is flooded, Fe oxides are transformed to soluble ferrous ions by accepting the electrons from Fe reducers. This process can significantly affect the fate of As in paddy fields. In this study, we show a novel technique to manipulate the Fe redox processes in paddy soils by deploying soil microbial fuel cells (sMFC). The results showed that the sMFC bioanode can significantly decrease the release of Fe and As into soil porewater. Iron and As contents around sMFC anode were 65.0% and 47.0% of the control respectively at day 50. The observed phenomenon would be explained by a competition for organic substrate between sMFC bioanode and the iron- and arsenic-reducing bacteria in the soils. In the vicinity of bioanode, organic matter removal efficiencies were 10.3% and 14.0% higher than the control for lost on ignition carbon and total organic carbon respectively. Sequencing of the 16S rRNA genes suggested that the influence of bioanodes on bulk soil bacterial community structure was minimal. Moreover, during the experiment a maximum current and power density of 0.31 mA and 12.0 mWm−2 were obtained, respectively. This study shows a novel way to limit the release of Fe and As in soils porewater and simultaneously generate electricity. Arsenic (As) release into paddy soil porewater can be limited by deploying soil microbial fuel cells (sMFC).

Original languageEnglish
Pages (from-to)647-655
Number of pages9
JournalEnvironmental Pollution
Volume238
DOIs
Publication statusPublished - Jul 2018

Keywords

  • Arsenic (As)
  • Bioanode
  • Dissolved organic matter (DOC)
  • Iron (Fe)
  • Microbial fuel cells
  • Paddy soil
  • Rice

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