Phototransformation of 4-chloro-2-methylphenol in water
The phototransformation of 4-chloro-2-methylphenol was studied using distilled water, solutions of humic substances and natural waters. Samples were irradiated at 280 nm, with polychromatic lamps emitting within the wavelength ranges 290 nm to 350 nm and 300 nm to 450 nm or exposed to sunlight. The photolysis of 4-chloro-2-methylphenol at 280 nm in pure aerated water leads to methylbenzoquinone as the main primary photoproduct; the quantum yield of the direct photolysis is equal to 0.66. When 4-chloro-2-methylphenol is irradiated alone by polychromatic light or exposed to solar-light, methylhydroquinone and methylhydroxybenzoquinone are found as main photoproducts because secondary photolysis of methylbenzoquinone occurs. Humic substances enhance the rate of photodegradation of 4-chloro-2-methylphenol at wavelengths greater than 300 nm. In these conditions, 4-chloro-2-methylphenol is transformed into methylhydroquinone, methylhydroxybenzoquinone essentially via direct photolysis and into 3-chloro-trans-trans and cis-trans-1-methyl-1-one-2, 4-hexadienoic acids through photoinduced reactions. These four photoproducts are found when 4-chloro-2-methylphenol is irradiated in natural waters at wavelengths greater than 300 nm. The phototransformation of 4-chloro-2-methylphenol under environmental conditions occurs therefore through both direct and humic substances-photoinduced processes.
Bibliographic Reference: Article: Journal of Photochemistry and Photobiology (1998)
Record Number: 199811175 / Last updated on: 1998-10-09
Original language: en
Available languages: en