WET OXIDATIVE METHOD FOR THE REMOVAL OF 2, 4, 6-TRICHLOROPHENOL IN WATER USING CO(II), MN(II), NI(II)-INCORPORATED FLY ASH CATALYSTS

Abstract

2, 4, 6-trichlorophenol is a persistent and carcinogenic water pollutant generated by various industries and is resistant to biological oxidation. The presence and removal of 2, 4, 6-trichlorophenol and other chlorophenols from the environment has received wide attention in recent times. In the present work, Mn(II), Co(II) and Ni(II) were incorporated separately into fly ash from a coal-based power plant and the materials were used as catalysts for oxidation of 2, 4, 6-trichlorophenol in water with the oxidant, H₂O₂. The catalysts were characterized by XRD and FTIR measurements. Before use, the materials were calcined at 773-823 K for 5 h. The oxidation reactions were carried out in a high pressure stirred reactor at 323 K under various reaction conditions. The conversion achieved with Mn(II), Co(II) and Ni(II) incorporated fly ash in 3 h was respectively 63.4, 61.9 and 68.9 % with 2, 4, 6-TCP : H₂O₂ molar ratio of 1:1. The oxidation followed second order kinetics having rate coefficient of 13.7 – 16.1 L mol^-1 min^−1. The results show that introduction of Mn(II), Co(II) and Ni(II) into fly ash through impregnation produces very effective catalysts for wet oxidation of 2, 4, 6-trichlorophenol.