Abstract

The kinetics of oxidation of various chlorophenols such as 2-chlorophenol (2-CP), 3-chlorophenol (3-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP), 2,6-dichlorophenol (2,6-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP) by potassium permanganate (0.8-3.2 mM) were studied in un-buffered solution with ionic strength ~0.02 M. Experimental results was indicated that the reaction of CPs with permanganate was of second-order overall (0.86 to 19.0 M-1s-1) and the reaction is first-order individually with respect to both permanganate and all chlorophenols (CPs) at an initial pH ~7.0 and 22°C. The degradation rate of chlorophenols can be accelerated by increasing oxidant concentration. The reaction rates of 4-CP with permanganate did not show any significant change over pH 5.5 to 8.5 and ionic strength ~0 to 0.2 M. The determined rate constants allowed us to predict the reaction rates of CPs with KMnO4 during oxidative treatment of CPs at contaminated sites.

Key words: Chlorophenols, kinetics, oxidation, potassium permanganate, rate constant.