OXIDATION OF AROMATIC-COMPOUNDS WITH UV RADIATION OZONE/HYDROGEN PEROXIDE/

A large variety of organic and inorganic compounds may be found in was tewater. Among these compounds, aromatics are characterized by their h igh toxicity and very low degradability by conventional treatments. Th is paper presents the results of an investigation about the oxidation of two substituted benzenes in a semibatch reactor: phenol, substitute d with an electron-donating group (-OH), and benzoic acid substituted with an electron- withdrawing group (-COOH). The advanced oxidation pr ocesses studied were UV, ozone, hydrogen peroxide and its combinations . The pH dependence and the influence of the initial concentration of hydrogen peroxide were studied to find the optimal conditions for a co mplete and fast oxidation of both compounds. Experimental results indi cated that both phenol and benzoic acid are destroyed more rapidly by ozone at higher pH (9-12), while ozonation combined with hydrogen pero xide or/and UV is considerably faster at low pH (3-7). (C) 1997 IAWQ. Published by Elsevier Science Ltd.