Especiação e remoção de arsenio de aguas utilizando voltametria de redissolução catodica e processos oxidativos avançados / Arsenic speciation and removal from waters employing stripping voltammetry and advanced oxidatives process

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Arsenic exists in various chemical forms in the environment, including as organic and inorganic species, originating from natural and anthropogenic sources. As for other potential toxic elements, the concentration limit for arsenic in drinking water is decreasing as a result of observed chronic poisoning coming from low exposure doses. In drinking water, the maximum acceptable concentration established in Brazil for drinking waters is 10 mg L (Portaria 518/2004-Ministério da Saúde) and 10 mg L for fresh waters (Portaria 357/2005-Conselho Nacional do Meio Ambiente). In this work, studies were performed to obtain the best conditions for As (III) and As (V) speciation in fresh and ground water samples by using a stripping voltammetry technique. Two methods based on advanced oxidative processes for removal arsenic from water samples were compared. The voltammetric method presented adequate sensitivity and selectivity for arsenic speciation. The limit of quantitation obtained was 2 mg L and the relative standard deviation (RSD) <3% was observed. A linear range from 2 to 80 mg L and correlation coeficient of 0.999 were obtained for both species. The removal processes studied in this work were the SORAS (Solar Oxidation and Removal of Arsenic) and heterogeneous photocatalysis with immobilized TiO2. The studies were performed in PET bottles and UV light was used as catalyst. The results obtained exceeded 99% of As removal. The voltammetric technique and the As removal processes were applied to fresh and ground water samples collected in the Ouro Preto region (MG state, Brazil) and both presented good results, showing possibility of application.

ASSUNTO(S)

arsenic voltammetry voltametria fotocatalise heterogenea heterogeneous photocatalysis arsenio

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