Abstract

The photocatalytic degradation of EDTA solutions (5 mM) has been studied under different conditions in the presence of TiO 2 in suspension or immobilized on glass rings and in the absence and presence of Fe(III). Using the response surface methodology, the initial pH, amount of photocatalyst, and the Fe/EDTA molar ratio were optimized in order to obtain better degradation. Under optimized conditions, 90% EDTA degradation (at a 0.28 Fe/EDTA molar ratio) was reached after 60 min illumination at pH 3.0 and using 0.73 g L -1 TiO 2. Increase of the acute toxicity (Microtox) was observed in the course of the reaction, and degradation intermediates were identified by GC/MS analysis. © 2005 Elsevier B.V. All rights reserved.