STUDIES REGARDING THE PHOTOCATALYTIC TRANSFORMATION OF ERYTHROSINE B

Abstract

Heterogeneous photochemical processes using semiconductors as a photocatalyst have gained wide interest in the treatment of dyes effluents from industries, where biological methods did not succeed, i.e. especially because of dyes toxicity on sludge. Experiments concerning the photocatalytic degradation of Erythrosine B xanthene dye were conducted in the presence of different semiconductor catalysts (TiO₂ P-25, TiO₂ -Rutile, ZrO and Sb₂O₃). The experiments showed that TiO₂ P-25 exhibited the best removal efficiency. Photocatalytic degradation rate decreased from 0.9 to 0.01 mg L^-1 min^-1 when Erythrosine B concentration increased from 30 mg L^-1 to 300 mg L^-1. The addition of hydrogen peroxide leads to increase of the reaction rate from 0.06 mg L^-1 min^-1 to 0.14 mg L^-1min^-1. Photocatalytic degradation of Erythrosine B led to a complete detoxification of compounds, but the complete mineralization was not achieved.