HSING-CHENG HSIYu T.-H.2022-11-162022-11-162007https://www.scopus.com/inward/record.uri?eid=2-s2.0-84933509384&partnerID=40&md5=78d102c7babc335684394c6b468d1e51https://scholars.lib.ntu.edu.tw/handle/123456789/625375This study examined the leaching characteristics of PCDD/Fs from raw and solidified APC residues using humic acid and n-hexane as leachants. PCDD/Fs were observed to stably retain in APC residues when these samples were multiply leached with humic acid and n-hexane. However, the leaching mechanisms of PCDD/Fs for samples treated with humic acid and n-hexane appeared to be different. Humic acid showed a stronger affinity to bind with highly chlorinated PCDD/Fs. Leaching of PCDD/Fs with n-hexane was, in contrast, primarily caused from the partition of hydrophobic PCDD/Fs between the APC residue surface and the liquid phase of n-hexane. S/S decreased the PCDD/F leachability at a leaching duration up to ∼90 h with humic acid. However, S/S significantly increased the PCDD/F leaching concentrations and rates with n-hexane. The toxicity of n-hexane leachates also markedly increased due to releasing a significant amount of low chlorinated PCDD/Fs after S/S. The effectiveness of activated carbon on inhibiting the PCDD/F release was also verified via both humic acid and n-hexane multiple leaching tests. © 2007 by the Air & Waste Management Association.Activated carbon; Biological materials; Carbon; Hexane; Leaching; Organic acids; Pollution control; Waste management; Air pollution control residues; Dibenzo p dioxins; Dibenzofurans; Leaching characteristics; Leaching concentrations; Leaching mechanism; Leaching test; Multiple extraction procedures; Air pollution controlconference paper2-s2.0-84933509384