WET OXIDATION OF PHENOL ANALOGUES USING Mn(II)@Silica AS HETEROGENEOUS CATALYST

Abstract

Toxic and bio-resistant phenolic compounds are some of the most common hazardous organics in aqueous systems presenting challenging problem in waste water treatment. In the present study, wet oxidation without a chemical oxidant was attempted using Mn(II)@silica as the catalyst. The catalysts were well characterized by physico-chemical characterization methods. The conversion of phenol, 2-chlorophenol and 2-nitrophenol was 89.7, 85.5 and 78.8 % with hydrothermally synthesized Mn(II)@silica, and 94.2, 91.1 and 89.4 % with impregnated Mn(II)@silica, respectively. The reactions followed pseudo first order kinetics. The effects of pH, reaction time, catalyst load, feed concentration, and temperature were investigated. GC-MS analysis showed that the persistent organics were oxidized to simpler end products. Further oxidation is expected lead to complete mineralization of the contaminants. Mn(II) coupled silica was noticed to be a better oxidation catalyst for the organic pollutants than the synthesized Mn(II)@silica.