Removal of arsenic from effluents - a comparison between the FeSO{sub 4}/Air and FeSO{sub 4}/H{sub 2}O{sub 2} systems
- Catholic Univ. of Rio de Janeiro (Brazil)
- BHP Minerals, Reno, NV (United States)
This paper reports the results of kinetic studies involving the precipitation of arsenic from aqueous solutions as FeAsO{sub 4} / Fe(OH){sub 3}, using FeSO{sub 4} as source of Fe ions, and Air or H{sub 2}O{sub 2} as oxidizing agents. Both systems lead to an efficient removal of arsenic. The differences in oxidants performances are in the precipitation reaction rate - much faster using hydrogen peroxide. Mechanisms of reactions were suggested based on the following main steps: Fe(II) oxidation: 2 Fe{sup 2+} + 1/2 O{sub 2} + 2 H{sup +} 2 Fe{sup 3+} + H{sub 2}O 2 Fe{sup 2+} + H{sub 2}O{sub 2} + 2 H{sup +}= 2 Fe{sup 3+} + 2 H{sub 2}O As(III) oxidation: HAsO{sub 2} + 2 Fe {sup 3+} + 2 H{sub 2}O = 2 Fe{sup 2+} + H{sub 3}AsO{sub 4} + 2H{sup +} HAsO{sub 2} + H{sub 2}O{sub 2} = H{sub 3}ASO{sub 4} Precipitation: Fe{sup 3+} + H{sub 3}AsO{sub 4} = FeASO{sub 4} (s) + 3 H{sup +} H{sub 3}AsO{sub 4} + n Fe(OH){sub 3} (s) = H{sub 3}ASO{sub 4} (ads) [Fe(OH){sub 3}]{sub n} (s). 15 refs., 7 figs.
- OSTI ID:
- 447182
- Report Number(s):
- CONF-961018-; TRN: 97:005211
- Resource Relation:
- Conference: Minerals, Metals and Materials Society (TMS) fall extraction and process metallurgy meeting, Scottsdale, AZ (United States), 27-30 Oct 1996; Other Information: PBD: 1996; Related Information: Is Part Of Second international symposium on extraction and processing for the treatment and minimization of wastes - 1996; Ramachandran, V.; Nesbitt, C.C. [eds.]; PB: 870 p.
- Country of Publication:
- United States
- Language:
- English
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