Catalytic ozonation: a promising advanced oxidation technology for water treatment

The first part of this paper presents generalities on molecular ozone react ivity. The second part focuses on catalytic ozonation with the objective to evaluate the efficiency of such an AOT versus ozonation alone. The literat ure data relative to catalytic ozonation concerns either the activation of ozone with metals in solution, or the heterogeneous behavior of solid catal ysts. Numerous metals (Fe, Mn, Ni, Co, Zn, Ag, Cr) under various forms (sal t of reduced metal, solid oxide, deposited metal on support) were reported to enhance the efficiency of ozone towards the removal (or the conversion) of different organic compounds in aqueous solution. Some years ago, heterog eneous catalytic ozonation has begun to be studied in our group. This paper presents a short synthesis of the main results obtained, illustrated by th ree different experimental procedures which can be used to test catalytic o zonation. Finally, some hypothesis on reaction mechanisms and prospects are examined. (C) 1999 Elsevier Science B.V. All rights reserved.