Kinetics and Mechanism of Photoactivated Periodate Reaction with 4-Chlorophenol in Acidic Solution.

The application of photoactivated periodate (UV/I04-) to the degradation of 4-chlorophenol (4-CP) was explored in this study. Under low irradiation intensities (23 μW/ cm2), wavelength of 266 nm, and pH 3, 4-CR was observed to degrade by pseudo-first-order reaction kinetics. The small reduction in 4-CP degradation in the presence of tert-butyl alcohol (t-BuOH) suggests that degradation of 4-CP by UV/lO4- was not dominated by an OH pathway. 03 production was suppressed in the presence of t-BuOH under O2-limited environments and in the presence of 4-CP. Faster degradation of 4-CP in the presence of an OW scavenger under nitrogen purging as compared to air- saturated conditions indicates that O(3P) is an important reactive species with 4-CR in this system. When 4-CP is added to the system, 103 production is enhanced. On the basis of the elimination of potential reaction pathways, O(3P) and lO3- are suspected reactive species with 4-CP in this system. [ABSTRACT FROM AUTHOR]