Immobilization mechanism of arsenic in waste solidified using cement and lime
- Katholieke Univ. Leuven, Heverlee (Belgium). Dept. of Chemical Engineering
The material studied, a waste fly ash from the metallurgical industry, contains the toxic element As in high concentrations, ranging from 23% to 47% (wt %). Besides As, Sb and Pb are present in the waste material. The waste was solidified with inorganic materials such as cement and pozzolanic materials in order to reduce the leachability of the contaminants from the waste. The optimal solidification recipe lowered the As concentration in the leachate of the extraction test DIN 38 414 S4 from ca. 5 g/L to ca. 5 mg/L. In this paper, it was shown that this enormous reduction in As concentration was due to the formation of CaHAsO{sub 3} in the leachate, in the presence of Ca(OH){sub 2}. Formation of CaHAsO{sub 3} alone cannot lower the arsenic concentration beneath ca. 55 mg/L, as was calculated with the speciation program MINTEQA2.
- OSTI ID:
- 655451
- Journal Information:
- Environmental Science and Technology, Vol. 32, Issue 18; Other Information: PBD: 15 Sep 1998
- Country of Publication:
- United States
- Language:
- English
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