Degradation of Organoarsenicals by Heterogeneous Photocatalysis using ZnO, TiO2 and UVA

MIRANDA, C.; SANTANDER, P.; MATSCHULLAT, J.; DAUS, B.; YÁÑEZ, J.; MANSILLA, H.:
Journal Of Advanced Oxidation Technologies, 19, 276-283 (2016).

DOI: 10.1515/jaots-2016-0211

Abstract

The oxidation of phenylarsine oxide (PhAsO) and cacodylic acid (CA) by UV-A assisted heterogeneous photocatalysis using ZnO and TiO2 was studied. The influence of pH and catalyst load was assessed using multifactorial design. Both studied variables showed a significant effect on organoarsenical degradation. PhAsO was completely removed in 5 min at pH 6.3 using TiO2 as catalyst under optimum conditions. In contrast, the same removal extent was achieved at a wider pH range (pH 4 to 10), when ZnO was used. A 100% degradation was reached for CA at 60 min irradiation using ZnO and pH 9.3. In comparison, only 60 % CA degradation was achieved using TiO2 at pH 6.5. Regarding the by-product formation during photocatalysis, the main degradation products found for PhAsO were phenylarsonic acid (PhAs), phenol and inorganic arsenate. With CA, only methanol and inorganic arsenate were found as main reaction products.

SEE MORE