Photooxidation of some mono-, di-, and tri-chlorophenols in aqueous solution by hydrogen peroxide UV combinations


APAK M. R. , Hugül M.

JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY, cilt.67, ss.221-226, 1996 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 67 Konu: 3
  • Basım Tarihi: 1996
  • Dergi Adı: JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
  • Sayfa Sayıları: ss.221-226

Özet

A number of chlorophenols, namely 2-, 3-, and 4-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol, have been decomposed in aqueous solution by using hydrogen peroxide as the oxidizing agent under UV radiation emitted by a 400 W high-pressure mercury lamp in a thermostatted Pyrex-glass column photoreactor, and the organic-bound chlorine has been converted into the environmentally harmless inorganic chloride. For H2O2/chlorophenol mole ratios between 1 : 1 and 16 : 1, the photooxidation reaction approached pseudo-first order kinetics, and the rate constants increased with increasing ratio of the oxidant. A theoretical model for the degradation pathway is proposed. The fact that the reaction order was not simply unity could be attributed to the complex reaction sequence processing via a radical mechanism through colored intermediates possibly comprising hydroquinone, catechol and resorcinol.