In the present work the hydrogen peroxide-assisted photochemical degradation of ethylenediaminetetraacetic acid (EDTA) is reported. The effect of pH and H2O2:EDTA molar ratio on the efficiency of the EDTA degradation was evaluated by using a 2(2) factorial design. Working at optimized experimental conditions (pH of 2 and H2O2:EDTA molar ratio of 10), using a microwave-activated photochemical reactor and monitoring the EDTA degradation by total organic carbon analysis, mineralization ratios higher than 90% were observed at reaction times of 6 min. (C) 2002 Elsevier Science Ltd. All rights reserved.71197202