TY - JOUR
T1 - Effects of cement on redistribution of trace metals and dissolution of organics in sewage sludge and its inorganic waste-amended products
AU - Lim, T. T.
AU - Chu, J.
AU - Goi, M. H.
PY - 2006
Y1 - 2006
N2 - The suitability of using cement-stabilized sludge products as artificial soils in earth works was evaluated. The sludge products investigated were cemented sludge, cement-treated clay-amended sludge (SS + MC), and cement-treated copper slag-amended sludge (SS + CS). The leachability of lead (Pb), zinc (Zn), copper (Cu), and chromium (Cr) were assessed using the sequential extraction technique, toxicity characteristic leaching procedure (TCLP), NEN 7341 availability test, and column leaching test. The results indicated that Zn leachability was reduced in all the cement-stabilized sludge products. In contrast, Cu was transferred from the organic fraction to the readily leachable phases in the cement-stabilized sludge products and therefore exhibited increased leachability. The increased Cu leachability could be attributed to dissolution of humic substances in the sludge as a result of elevated pH. Good correlation between dissolved organic carbon (DOC) and heavy metal leaching from the cement-stabilized sludge products was observed in the column leaching experiment. Even with a cement percentage as small as 12.5%, calcium silicate hydrate (C-S-H) was formed in the SS + MC and SS + CS products. Inclusion of the marine clay in the SS + MC products could reduce the leaching potentials of Zn, and this was the great advantage of the marine clay over the copper slag for sludge amendment.
AB - The suitability of using cement-stabilized sludge products as artificial soils in earth works was evaluated. The sludge products investigated were cemented sludge, cement-treated clay-amended sludge (SS + MC), and cement-treated copper slag-amended sludge (SS + CS). The leachability of lead (Pb), zinc (Zn), copper (Cu), and chromium (Cr) were assessed using the sequential extraction technique, toxicity characteristic leaching procedure (TCLP), NEN 7341 availability test, and column leaching test. The results indicated that Zn leachability was reduced in all the cement-stabilized sludge products. In contrast, Cu was transferred from the organic fraction to the readily leachable phases in the cement-stabilized sludge products and therefore exhibited increased leachability. The increased Cu leachability could be attributed to dissolution of humic substances in the sludge as a result of elevated pH. Good correlation between dissolved organic carbon (DOC) and heavy metal leaching from the cement-stabilized sludge products was observed in the column leaching experiment. Even with a cement percentage as small as 12.5%, calcium silicate hydrate (C-S-H) was formed in the SS + MC and SS + CS products. Inclusion of the marine clay in the SS + MC products could reduce the leaching potentials of Zn, and this was the great advantage of the marine clay over the copper slag for sludge amendment.
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U2 - 10.1016/j.wasman.2005.11.001
DO - 10.1016/j.wasman.2005.11.001
M3 - Article
C2 - 16364627
AN - SCOPUS:33748617577
SN - 0956-053X
VL - 26
SP - 1294
EP - 1304
JO - Waste Management
JF - Waste Management
IS - 11
ER -
