Partitioning variation of heavy metals in contaminated river sediment via bioleaching: effect of sulfur added to total solids ratio

• Published in: Water research (Oxford) 2003-11, Vol.37 (19), p.4623-4630
• Main Authors: Tsai, Li-Jyur, Yu, Kuang-Chung, Chen, Shu-Fen, Kung, Pei-Yi, Chang, Chia-Yuan, Lin, Chao-Hsien
• Format: Article
• Language: English
• Subjects: Applied sciences; Bacteria; Bioleaching; Biological and medical sciences; Biological Availability; Biotechnology; Decontamination. Miscellaneous; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environment and pollution; Environmental Monitoring; Exact sciences and technology; Freshwater; Fundamental and applied biological sciences. Psychology; Geologic Sediments - chemistry; Heavy metal; Hydrogen-Ion Concentration; Industrial applications and implications. Economical aspects; Metals, Heavy - analysis; Metals, Heavy - chemistry; Miscellaneous; Pollution; Pollution, environment geology; Sediment; Sequential extraction procedure; Soil and sediments pollution; Sulfur - chemistry; Sulfur - metabolism; Sulfur-oxidizing bacteria; Total solids; Water Microbiology; Water Pollutants - analysis
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2003.07.003

The aim of this study was to determine the effect of the ratio of sulfur added to total sediment solids (SA/TS) on the remobilization of heavy metals from contaminated river sediment by indigenous sulfur-oxidizing bacteria. Also, the difference in metal binding fractions before and after bioleaching was explored. It was found that sediment pH decreased at a significantly faster rate at higher SA/TS ratios (0.413 and 0.199) than at lower ones. Sulfate concentrations increased at a faster rate at these higher SA/TS ratios. At the lower SA/TS ratios, more acid must be produced and therefore it took more time for sulfur-oxidizing bacteria to lower the sediment pH. Remobilization efficiency of total extractable Pb and Cr was significantly higher at higher SA/TS ratios. After bioleaching, Mn-oxides became a stronger binding pool, and the percentage of Pb and Zn bound to Mn-oxides and Cr and Cu bound to organic matter increased with the decrease of SA/TS. Different heavy metals showed different binding behavior at the various SA/TS ratios.