title: Bioleaching of arsenic from highly contaminated mine tailings using Acidithiobacillus thiooxidans.
abstract: The behavior of arsenic (As) bioleaching from mine tailings containing high amount of As (ca. 34,000 mg/kg) was investigated using Acidithiobacillus thiooxidans to get an insight on the optimal conditions that would be applied to practical heap and/or tank bioleaching tests. Initial pH (1.8-2.2), temperature (25-40 °C), and solid concentration (0.5-4.0%) were employed as experimental parameters. Complementary characterization experiments (e.g., XRD, SEM-EDS, electrophoretic mobility, cell density, and sulfate production) were also carried out to better understand the mechanism of As bioleaching. The results showed that final As leaching efficiency was similar regardless of initial pH. However, greater initial As leaching rate was observed at initial pH 1.8 than other conditions, which could be attributed to greater initial cell attachment to mine tailings. Unlike the trend observed when varying the initial pH, the final As leaching efficiency varied with the changes in temperature and solid concentration. Specifically, As leaching efficiency tended to decrease with increasing temperature due to the decrease in the bacterial growth rate at higher temperature. Meanwhile, As leaching efficiency tended to increase with decreasing solid concentration. The results for jarosite contents in mine tailings residue after bioleaching revealed that much greater amount of the jarosite was formed during the bioleaching reaction at higher solid concentration, suggesting that the coverage of the surface of the mine tailings by jarosite and/or the co-precipitation of the leached As with jarosite could be a dominant factor reducing As leaching efficiency.
authors.affiliation: Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 561-756, Republic of Korea.
authors.forename: Eunseong
authors.initials: E
authors.lastname: Lee
authors.affiliation: Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 561-756, Republic of Korea.
authors.forename: Yosep
authors.initials: Y
authors.lastname: Han
authors.affiliation: Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 561-756, Republic of Korea.
authors.forename: Jeonghyun
authors.initials: J
authors.lastname: Park
authors.affiliation: Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 561-756, Republic of Korea.
authors.forename: Jeongsik
authors.initials: J
authors.lastname: Hong
authors.affiliation: Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 561-756, Republic of Korea.
authors.forename: Rene A
authors.initials: RA
authors.lastname: Silva
authors.affiliation: Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 561-756, Republic of Korea.
authors.forename: Seungkon
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju, Jeonbuk 561-756, Republic of Korea. Electronic address: kshjkim@jbnu.ac.kr.
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Kim
mesh_terms: D013856:Acidithiobacillus thiooxidans / Q000378:metabolism*; D001151:Arsenic / Q000737:chemistry* / Q000378:metabolism*; D005290:Ferric Compounds; D007220:Industrial Waste; D008906:Mining; D013431:Sulfates; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005290:Ferric Compounds; D007220:Industrial Waste; D013431:Sulfates; D014874:Water Pollutants, Chemical; C492331:jarosite; D001151:Arsenic
keywords: Acidithiobacillus thiooxidans; Arsenic bioleaching; Cell attachment; Jarosite; Mine tailings; Sulfate production