Enhancing As(V) adsorption and passivation using biologically formed nano-sized FeS coatings on limestone: Implications for acid mine drainage treatment and neutralization. (February 2017)

• Record Type: Journal Article
• Authors: Liu, Jing; Zhou, Lei; Dong, Faqin; Hudson-Edwards, Karen A.
• Is Part Of: Chemosphere. Volume 168(2017)
• Page Start: 529
• Page End: 538
• Publication Date: 2017-02
• Subjects: Fe-reducing bacteria -- Sulfate-reducing bacteria -- Sorption -- Arsenic(V) -- Nano -- FeS-coated limestone; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2016.11.037
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The iron-reducing bacterium Acidiphilium cryputum JF-5 and a sulfate reducing bacterium (SRB) collected and purified from the mine drainage of a copper mine in the northwest of Sichuan Province, China, were used to biologically synthesize nano-sized FeS-coated limestone to remove As(V) from solution. The adsorption efficiency of As(V) is improved from 6.64 μg/g with limestone alone to 187 μg/g with the FeS coated limestone in both batch and column experiments. The hydraulic conductivity of the columns are also improved by the presence of the nano-sized FeS coatings, but the solution neutralization performance of the limestone can be reduced by passivation by gypsum and Fe(III) precipitates. Calculations for FeS-coated limestone dissolution experiments show that the process can be described as nCa.sol = At 1/2 − nCa, gyp . The results suggest that FeS-coated limestone may be an effective medium for remediating As(V)-bearing solutions such as acid mine drainage in systems such as Permeable Reactive Barriers. Highlights: Fe-reducing JF-5 and SO4 -reducing SRB bacteria can together form nano-sized FeS. This FeS can improve adsorption performance of As(V) on limestone. Neutralization ability of limestone decreases due to passivation. Dissolution of FeS-coated limestone can be described by nCa.sol = At 1/2 − nCa, gyp . FeS-coated limestone may be good filling material for permeable reactive barriers.