Mode of occurrence and mobility of trace elements in fly ash and sewage sludge in view of environmentally safe reuse potential
The chemical speciation and potential release of trace elements in fly ash (FA), pure FA with flue gas desulfurization products (FA+FGDS), and sewage sludge from a municipal wastewater treatment works (SS), was assessed with use of a sequential extraction procedure. The major forms of trace element binding in all studied materials appeared to be moderately and easily reducible Fe- and Mn- amorphous oxides and in sewage sludge also humic-like soluble organic substances of a moderate binding strength and mobility. Trace elements (Pb, Cd, as well as Zn and Ni in FA and FA+FGDS) showed high affinity to stable binding in the immobile residual phase. Occurrence of the most labile binding phases was related to the forms of Ca2+ ion presence in exchangeable cites or as carbonate. The particularly problematic material due to the highest load of mobilizable trace elements and considerable rate of their enrichment in the most labile phases was found to be sewage sludge. Of two types of fly ash, pure FA contained the lowest load of trace elements readily available for release to the environment, while FA+FGDS could be the most prospective material for reuse due to buffering and cementing properties, despite of trace element enrichment in a mobile carbonate phase.
Binding strength chemical speciation reuse fly ash sewage sludge trace elements release
I. Twardowska K. Janta-Koszuta S. Stefaniak
Polish Academy of Sciences, Institute of Environmental Engineering, 34 Curie-Sklodowska St., Zabrze, 41-819, Poland
国际会议
第九届痕量元素生物地球化学国际会议(9th International Conference on the Biogeochemistry of Trace Elements)
北京
英文
378-379
2007-07-15（万方平台首次上网日期，不代表论文的发表时间）