________________________________________ * Author for correspondence; E-mail: abohasan_hilla@yahoo.com Int. J. Chem. Sci.: 10(1), 2012, 586-598 ISSN 0972-768X www.sadgurupublications.com PHOTOCATALYTIC DEGRADATION OF EDTA BY USING TiO 2 SUSPENSION AYAD F. ALKAIM and FALAH H. HUSSEIN * Chemistry Department, College of Science, Babylon University, HILLA, IRAQ ABSTRACT The photocatalytic degradation of an aqueous solution of ethylene diamminetetra-acetic acid (EDTA) has studied under different conditions in the presence of TiO 2 suspension. The effect of various parameters such as mass of titanium dioxide, EDTA concentration, light intensity, addition of H 2 O 2 and flow rate of O 2 on the photocatalytic degradation were investigated. Results showed that, the photocatalytic degradation process was high at the beginning and then decreased with time. This process was well described by pseudo, first order kinetics according to the Langmuir-Hinshelwood model. The results explained the photocatalytic degradation efficiency, which was increased by increasing catalyst loading from 1 g to 2 g. The degradation efficiency decreased with the increase in catalyst loading. Results also showed that the rate of photocatalytic degradation was increased with decreasing EDTA concentration. The proper amount of hydrogen peroxide improved the rate of photocatalytic degradation of EDTA, while the excess hydrogen peroxide quenched that formation of hydroxyl radicals  OH, which caused reducing at the rate of photocatalytic degradation. The effect of dissolved oxygen level of bubbling pure oxygen gas into the solution has been found to enhance the photodegradation rate. Results indicated that the photocatalytic degradation was enhanced by increasing light intensity. Key words: EDTA, Photocatalytic degradation, Titanium dioxide, Kinetic study, Light intensity. INTRODUCTION EDTA is used as a complexing agent and has wide applications in the pharmaceutical, agriculture and as a domestic cleaning of boilers. In recent years, EDTA was found in fresh water, sewage effluents and ground water, that paid much attention because its low bio-degradability and the capability for formation very stable complexes with heavy metals, which prevent theses complexes from re-dissolved again in water 1,2 .