Heavy metals were removed from industrial sludge by traditional and microwave-assisted acid extraction approaches. The effects of acid concentration, extraction time, sludge particle size and solid/liquid (S/L) ratio on copper-extraction efficiency were assessed. Leaching with increased acid concentrations increased the yield of heavy metals from the industrial sludge. In microwave-assisted acid extraction, reducing the S/L ratio and sludge particle size increased copper-extraction efficiency. These experimental findings indicate that S/L ratio most strongly influenced microwave-assisted acid extraction. Both traditional and microwave-assisted acid extraction demonstrate that sulfuric acid was an effective extractant, and the copper fraction in extracted sludge shifted from being primarily bound to Fe–Mn oxides and organic-matter partition, to being mostly bound to organic matter, remaining as a residue during acid extraction.
Research Article|January 01 2009
Recovery of heavy metals from industrial sludge using various acid extraction approaches
C. H. Wu
C. Y. Kuo
Water Sci Technol (2009) 59 (2): 289-293.
C. H. Wu, C. Y. Kuo, S. L. Lo; Recovery of heavy metals from industrial sludge using various acid extraction approaches. Water Sci Technol 1 January 2009; 59 (2): 289–293. doi: https://doi.org/10.2166/wst.2009.859
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