title: Enhancing As(V) adsorption and passivation using biologically formed nano-sized FeS coatings on limestone: Implications for acid mine drainage treatment and neutralization.
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= At1/2- 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.
authors.affiliation: The Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Liu
authors.affiliation: The Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhou
authors.affiliation: The Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, China.
authors.forename: Faqin
authors.initials: F
authors.lastname: Dong
authors.affiliation: Department of Earth and Planetary Sciences, Birkbeck, University of London, Malet St., London, WC1E 7HX, UK. Electronic address: k.hudson-edwards@bbk.ac.uk.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Hudson-Edwards
mesh_terms: D041801:Acidiphilium / Q000254:growth & development; D000327:Adsorption; D001152:Arsenicals / Q000302:isolation & purification*; D001673:Biodegradation, Environmental; D002119:Calcium Carbonate / Q000737:chemistry*; D002681:China; D016969:Desulfovibrio vulgaris / Q000254:growth & development; D005296:Ferrous Compounds / Q000737:chemistry*; D060587:Groundwater / Q000737:chemistry / Q000382:microbiology; D008906:Mining; D053758:Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D001152:Arsenicals; D005296:Ferrous Compounds; D014874:Water Pollutants, Chemical; D002119:Calcium Carbonate; C022597:ferrous sulfide
keywords: Arsenic(V); Fe-reducing bacteria; FeS-coated limestone; Nano; Sorption; Sulfate-reducing bacteria