Abstract
The photolysis of 2-chlorophenol in natural waters was investigated at pH 11.0 using monochromatic light (500 W xenon-lamp + monochrometer). Water samples were concentrated from 5 to 20-fold. The concentration of 2-chlorophenol was 1.6×10-6 mol·l-1 (0.20 ppm). The following results were obtained.
(1) The indirect photolysis rate constants in an infinitesimally thin layer increased linearly with increasing DOC of water samples as predicted theoretically.
(2) The percentage contribution of indirect photolysis to overall one at 300 nm was about 50% and increased with increasing wavelength. The overall photolysis rates calculated with solar illumination intensity showed a maximum at 325 nm.
(3) The quantum yields of direct photolysis were 0.34-0.43 at all wavelengths and those of indirect photolysis decreased from about 10-3 (300 nm) to 10-5 (350 nm).
