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Influence of Sulfur Concentration on Bioleaching of Heavy Metals from Industrial Waste Sludge
Author(s) -
Lin YenHui,
Juan MuLing,
Huang HauLiang,
Tsai HuiYing,
Lin Pearl HsuiPing
Publication year - 2010
Publication title -
water environment research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.356
H-Index - 73
eISSN - 1554-7531
pISSN - 1061-4303
DOI - 10.2175/106143010x12609736966720
Subject(s) - bioleaching , sulfur , chemistry , sulfate , acidithiobacillus thiooxidans , industrial waste , environmental chemistry , nickel , copper , nuclear chemistry , metallurgy , waste management , acidithiobacillus ferrooxidans , materials science , organic chemistry , engineering
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.