HETEROGENEOUSCATALYZEDINDUCED OXIDATION OFSOMEORGANIC POLLUTANTS

Abstract

Kinetics of oxidation of thionine:dye by H202 catalyzed by transition metal complexes has ' been studied spectrophotometricMly at A. = 599 nm. The complexes were supported on - I silica gel, alumina, silica - alu$na (25% AhOJ), and cation exchange resins surface. Among these complexes are : d:u (II) ammine [Cu(amm)4)2+, Cu (II) - methylamine [Cu(ma)4f+, Cu (II)- ethylenedia ne [Cu(en)2]2+, Co(II)- affimine [Co(amm)6f+, Ni (II)­ ammine [Ni(amm)6 2+. The reactiFn exhibited second - order kinetics : being first order with respect to each individual reaytant. The reactivity of metal complexes has the sequence : Silica I [Cu(ma)4]2+ > silica I [CJ(amm)4f+ > silica I [Cu(enhf+ while the metal ion has I the order : Ni (II) > Cu (II) > Co (II). The effect of surface has thr order : silica > resin > alumina. A reaction mechanism! involving the generation of free radical as active intermediate has been proposed.