Degradation of Toluene by Liquid Ferrate(VI) and Solid Ferrate(VI) in Aqueous Phase

Abstract

Ferrate(VI) ([FeO4]2−) is one of the innovative oxidation processes that has a strong oxidizing power. In this study, degradation of toluene has been examined using liquid sodium ferrate(VI) and solid potassium ferrate(VI). The effects of pH, molar ratio, and temperature on toluene removal by both ferrates(VI) were investigated. The highest toluene removal efficiency was achieved at neutral pH condition (pH=6.8) after a reaction period of 2 min. For the effect of molar ratio, the degradation efficiency increased as the molar ratio increased. The highest toluene degradation was achieved at molar ratio [(FeO42−]:[Toluene)] of 4.23:1 by both ferrates(VI). The optimal temperature was 45°C with kapp value of 389.7 M−1 s−1 and activation energy of 79.4 kJ/mol for liquid ferrate(VI), and kapp value of 567.21 M−1 s−1 and activation energy of 76.8 kJ/mol for solid ferrate(VI). The intermediate products such as heptanal, 3-methylbutanal, 2-methylhexane, 2-methylbutan-1-ol, 1-chlorobutane, 4-chlorobutane-1-ol, and 1-chloro-2-methylpropane were identified and the possible degradation pathways have been proposed.