Tracking of arsenics during the thermal stabilization of an AsH3 scrubber sludge.
Toxic arsenics in an AsH(3) scrubber sludge were thermally stabilized in the temperature range of 973-1,373 K. To better understand how the high-temperature treatments can stabilize arsenics in the sludge, their synchrotron X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectra of arsenics were determined. It is found that the reduced arsenic leachability may be associated with the formation of As(2)O(5) (51-59%) and embedded As(V) within the Ca(3)(PO(4))(2) matrix (41-49%) in the stabilized sludge. In addition, the As-O bond distances in the stabilized As(2)O(5) are much less than that of normal As(2)O(5) by 0.05-0.07 Å. The shorter As-O bond distances accompanied with the higher bonding energy also have a contribution to the thermal stabilization of arsenics.
Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Chinese Taiwan E-mail: wanghp@mail.ncku.edu.tw.
Chang-Yu
CY
Liao
Fang-Chih
FC
Chang
H Paul
HP
Wang
Yu-Ling
YL
Wei
Chih-Ju G
CJ
Jou
D001151:Arsenic / Q000737:chemistry*; D001152:Arsenicals / Q000737:chemistry*; D006358:Hot Temperature; D012722:Sewage / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy
D001152:Arsenicals; D012722:Sewage; D001151:Arsenic; C006633:arsine