Caffeine Oxidation in Water by Fenton and Fenton-Like Processes: Effects of Inorganic Anions and Ecotoxicological Evaluation on Aquatic Organisms

• Autor(a) principal: Oliveira,Thaís D. de
• Data de Publicação: 2015
• Outros Autores: Martini,William S., Santos,Mellina D. R., Matos,Maria Auxiliadora C., Rocha,Lilian L. da
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532015000100178
• topic: caffeine degradation; Fenton’s reagent; Fenton-like reagent; inorganic ion effects; ecotoxicological evaluation

Caffeine degradation using Fenton’s reagent (Fe(II)/H2O2) and the Fenton-like reagent (Fe(III)/H2O2) was investigated in deionized water at an initial concentration of 5.2 μmol L-1 (1000 μg L-1). These two different oxidation processes were compared and it was observed that efficient caffeine degradation (95%) was promoted by Fenton’s reagent at an Fe(II)/H2O2 molar ratio of 3:10 after 30 min. The effect of chloride, sulfate and carbonate ions on the decomposition of caffeine by Fenton’s reagent and the Fenton-like reagent has been investigated. Also, the chronic toxicity of the caffeine degradation products was evaluated on aquatic life after treatment of a solution initially containing caffeine by Fenton’s reagent using an Fe(II)/H2O2 ratio of 3:10. Only when Ceriodaphnia dubia was exposed to the concentration of 100% v/v of this solution obtained after the treatment of caffeine by Fenton’s reagent using an Fe(II)/H2O2 ratio of 3:10, chronic toxicity over the evaluated microcrustacean was observed.