title: Kinetic studies on UV-photodegradation of some chlorophenols using TiO2 catalyst.
abstract: A number of chlorophenols, namely 2-chlorophenol, 2,4,-dichlorophenol and 2,4,6-trichlorophenol, were decomposed in aqueous solution by using TiO2 as photoactivated catalyst under UV radiation emitted by a 125W medium pressure Hg lamp in an immersion well-type quartz photoreactor. The organic-bound chlorine was converted into the environmentally harmless inorganic chloride. For catalyst doses between 0.1 and 0.5gl(-1) the reaction mechanisms are elucidated. The corresponding rate constants were obtained by periodically measuring the remaining chlorophenol, and converted chloride in solution. A theoretical model for the degradation pathway is proposed expressing the rate as a linear function of the concentrations of chlorophenol and catalyst. Aside from the model-calculated values, the pseudo-first order rate constants for a rough approximation of chlorophenols degradation as well as the kinetic parameters of Langmuir-Hinshelwood type decomposition are compared. The photodegradation rate of chlorophenols followed the order: C13 x Ph > Cl2 x Ph > Cl x Ph.
authors.affiliation: Department of Chemistry, Faculty of Engineering, Istanbul University, Avcilar, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Hügül
authors.forename: Erol
authors.initials: E
authors.lastname: Erçağ
authors.forename: Reat
authors.initials: R
authors.lastname: Apak
mesh_terms: D002733:Chlorophenols / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D004785:Environmental Pollutants / Q000032:analysis*; D007700:Kinetics; D009153:Mutagens / Q000737:chemistry*; D010777:Photochemistry; D014025:Titanium / Q000737:chemistry*
chemical_list: D002733:Chlorophenols; D004396:Coloring Agents; D004785:Environmental Pollutants; D009153:Mutagens; C009495:titanium dioxide; D014025:Titanium; C030683:2-chlorophenol; C024564:2,4,6-trichlorophenol; C004762:2,4-dichlorophenol