Removal of arsenic from effluents - a comparison between the FeSO{sub 4}/Air and FeSO{sub 4}/H{sub 2}O{sub 2} systems

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:447182

Teixeira, L A; Kohler, H M ^[1]; Kohler, H M ^[1]; Monteiro, A G ^[2]

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1. Catholic Univ. of Rio de Janeiro (Brazil)
2. 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--
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
ARSENIC
CHEMICAL EFFLUENTS
CHEMICAL REACTION KINETICS
EFFICIENCY
MINING
OXIDIZERS
PRECIPITATION
URANIUM ORES