Kinetic studies on UV-photodegradation of some chlorophenols using TiO2 catalyst


Hugül M., ERÇAĞ E. , APAK M. R.

JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING, cilt.37, ss.365-383, 2002 (SCI İndekslerine Giren Dergi) identifier identifier identifier identifier

  • Cilt numarası: 37 Konu: 3
  • Basım Tarihi: 2002
  • Doi Numarası: 10.1081/ese-120002835
  • Dergi Adı: JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING
  • Sayfa Sayıları: ss.365-383

Özet

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 125 W 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 0.5 gl(-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: Cl-3.Ph > Cl-2.Ph > Cl.Ph.