title: Influence of sulfur concentration on bioleaching of heavy metals from industrial waste sludge.
abstract: The bioleaching process, including acidification and solubilization of heavy metals, is a promising method for removing heavy metals from industrial waste sludge. Solubilization of heavy metals in industrial waste sludge is governed by adding elemental sulfur. A sulfur concentration exceeding 0.5% (w/v) inhibits sulfate production and the activity of acidophilic bacteria. Sulfate production was described well by a substrate inhibition expression in Haldane's kinetics. After 15 days of bioleaching, 79 to 81% copper, 50 to 69% lead, and 49 to 69% nickel were solubilized from sludge with a sulfur concentration of 0.5 to 1.0% (w/v). Experimental results indicated that the optimal sulfur concentration for the maximum solubilization rate of copper and nickel was 0.5% (w/v) and 1.0% (w/v) for lead. The profiles of denaturing gradient gel electrophoresis confirmed that indigenous acidophilic Acidithiobacilli (A. thiooxidans and A. ferrooxidans) existed and were the dominant species in the bioleaching process.
authors.affiliation: Department of Safety, Health and Environmental Engineering, Central Taiwan University of Science and Technology, Taichung, Taiwan. yhlin1@ctust.edu.tw
authors.forename: Yen-Hui
authors.initials: YH
authors.lastname: Lin
authors.forename: Mu-Ling
authors.initials: ML
authors.lastname: Juan
authors.forename: Hau-Liang
authors.initials: HL
authors.lastname: Huang
authors.forename: Hui-Ying
authors.initials: HY
authors.lastname: Tsai
authors.forename: Pearl Hsui-ping
authors.initials: PH
authors.lastname: Lin
mesh_terms: D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000032:analysis*; D019216:Metals, Heavy / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D012995:Solubility; D013431:Sulfates; D013455:Sulfur / Q000737:chemistry*; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D007220:Industrial Waste; D019216:Metals, Heavy; D012722:Sewage; D013431:Sulfates; D014874:Water Pollutants, Chemical; D013455:Sulfur