Fotocatálise heterogênea com TiO2 para oxidação de arsênio e sua remoção de águas por coprecipitação com sulfato férrico

Abstract

Recebido em 7/7/08; aceito em 10/2/09; publicado na web em 3/7/09 HETEROGENEOUS PHOTOCATALYSIS WITH TiO 2 FOR THE OXIDATION OF ARSENIC AND ITS REMOVAL FROM WATER BY COPRECIPITATION WITH FERRIC SULFATE. The oxidation of arsenic (As(III) to As(V)) in water samples was performed by heterogeneous photocatalysis using a TiO 2 film immobilized inside a photochemical reactor. After oxidation, As(V) was removed from the water samples by coprecipitation with ferric sulfate. The final conditions of oxidation and arsenic removal (TiO 2 film prepared with a suspension: 10% (w/v); pH: 7.0; oxidation time: 30 min and Fe 3+ concentration: 50 mg L-1) were applied in natural water samples which were supplemented with 1.0 mg L-1 of As(III) to verify the influence of the matrix. After treatment, more than 99% of arsenic was removed from the water.