KINETICS OF OZONATION OF PENTACHLOROPHENOL IN AQUEOUS-SOLUTIONS

This research investigates the kinetics of the reaction between dissol ved ozone and pentachlorophenol in acidic and neutral buffer solutions over the temperature range of 10 degrees to 40 degrees C. The reactio n is very fast and five to six moles of ozone are required for convers ion of each more of pentachlorophenol. The overall kinetics are second order, with first order each in the concentrations of ozone and penta chlorophenol. At 25 degrees C, the overall rate constant ranges from 7 .55 x 10(4) to 2.49 x 10(7) L/Ms as the solution pH changes from 2 to 7. The ozonation rate increases as the fraction of pentachlorophenate in the solution increases, and the rate constant varies in proportion to [HO-](0.75) in the pH range of about 2 to 5. The reaction is enhanc ed by temperature, and correlations by the Arrhenius equation yield an average activation energy of 27 kJ/mole.