US EPA

2807532 

Journal Article 

Degradation of carbofuran in water by solar photocatalysis in presence of photosensitizers 

Kuo, WS; Chiang, YH; Lai, LS 

2006 

Yes 

Journal of Environmental Science and Health, Part B: Pesticides, Food Contaminants, and Agricultural Wastes
ISSN: 0360-1234
EISSN: 1532-4109 

England 

41 

6 

937-948 

English 

16893781 

10.1080/03601230600806137 

WOS:000239571700014 

The effect of the presence of photosensitizers, methylene blue (MB) and rose Bengal (RB), on the degradation of carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) in water in a solar photocatalytic system was investigated. It was found that as compared to MB, RB generally showed a stronger effect on the decomposition of carbofuran under comparable conditions. Among the conditions studied, adding 2 x 10(-6) M of RB, that corresponding to 2% of the initial concentration of carbofuran solution in the system, rendered the most effective degradation of carbofuran. As a result, a carbofuran removal percentage of 69.9%, a mineralization efficiency of 28.0%, and a microtoxicity reduction of 65.0% could be achieved. The degradation and mineralization of carbofuran was found to follow the pseudo-first order reaction kinetics. The decomposition mechanism of carbofuran was further investigated through identification of the intermediates to elaborate the influence of dye photosensitizer on the solar photocatalysis of carbofuran in water. On the basis of the intermediates identified, including carbofuran phenol, 3-hydroxy carbofuran phenol, and substituted alcohols (3-phenoxy 1-propanol, 2-ethyl 1-hexanol, 2-butoxyl ethanol), it appears that hydrolysis and hydroxylation were the two key mechanisms for decomposing carbofuran during the process of solar photocatalysis with the aid of dye photosensitizer. 

solar photocatalysis; carbofuran; TiO2 film; photosensitizer; methylene blue; rose Bengal