Abstract
The oxidation efficiency of hydroxyl radical generated from the photo‐dissociation of hydrogen peroxide was determined in the photooxidation of 2‐chloro‐phenol (7.8×10‐6 mol.1‐1) at pH 3.0 and 13.0. The oxidation efficiency observed at pH 3.0 in the early stage of decomposition was almost unity at low concentration of hydrogen peroxide (1.0×10‐4 mol.1‐1) and decreased with increasing the concentration of hydrogen peroxide. The observed oxidation efficiency was in fair agreement with the values calculated theoretically, assuming that hydroxyl radical reacts only with 2‐chlorophenol and hydrogen peroxide. The oxidation efficiency at pH 13.0 was below 0.05 in all experimental conditions examined.