Photocatalytic degradation of endocrine disruptor compounds under simulated solar light

Nanostructured titanium materials with high UV-visible activity were synthesized in the collaborative project Clean Water FP7. In this study, the efficiency of some of these catalysts to degrade endocrine disruptor compounds, using bisphenol A as the model compound, was evaluated. Titanium dioxide P25 (AEROXIDE® TiO2, Evonik Degussa) was used as the reference. The photocatalytic degradation was carried out under the UV part of a simulated solar light (280–400 nm) and under the full spectrum of a simulated solar light (200 nm-30 μm). Catalytic efficiency was assessed using several indicators such as the conversion yield, the mineralization yield, by-product formation and the endocrine disruption effect of by-products. The new synthesized catalysts exhibited a significant degradation of bisphenol A, with the so-called ECT-1023t being the most efficient. The intermediates formed during photocatalytic degradation experiments with ECT-1023t as catalyst were monitored and identified. The estrogenic effect of the intermediates was also evaluated in vivo using a ChgH-GFP transgenic medaka line. The results obtained show that the formation of intermediates is related to the nature of the catalyst and depends on the experimental conditions. Moreover, under simulated UV, in contrast with the results obtained using P25, the by-products formed with ECT-1023t as catalyst do not present an estrogenic effect.We are grateful for the funding of the European Commission through the Clean Water Project which is a Collaborative Project (Grant Agreement number 227017) co-funded by the Research DG of the European Commission within the joint RTD activities of the Environment and NMP Thematic Prioritie

Photocatalytic degradation of estradiol under simulated solar light and assessment of estrogenic activity

International audienceThe ability of nanostructured titanium materials developed in the FP7/EU collaborative Clean Water project to photocatalytically degrade pollutants was tested, using 17 beta-estradiol (E2) as the model compound. The photocatalytic degradation of E2 was carried out under simulated solar light (both the UV part (280-400 nm) and full spectrum (200 nm-30 mu m)). The efficiency of the process was assessed using several indicators including the conversion yield, the mineralization yield, the formation of by-products and their endocrine disrupting effects. The newly synthesized catalysts significantly degraded E2 and their efficiency was found to depend on the irradiation wavelength range. Some of the intermediates formed during the photocatalytic treatment with ECT-1023t and Evonik P25 were identified and their estrogenic effect was evaluated in vivo using the ChgH-GFP transgenic medaka line. This analysis confirmed that in the structure of the identified by-products, the phenol group is not destroyed and that the estrogenic effect is still present in the corresponding solution. The persistence of the estrogenic effect after the photocatalytic treatment is hypothesized to be due to the presence of the phenol group in the by-products. (C) 2014 Published by Elsevier B.V