Sequential photochemical-biological degradation of chlorophenols

Research output: Contribution to journalArticle


UV/TiO2/H2O2, UV/TiO2 and UV/H2O2 were compared as pre-treatment processes for the detoxification of mixtures of 4-chlorophenol (4CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP) and pentachlorophenol (PCP) prior to their biological treatment. When each chlorophenol was initially supplied at 50mg l(-1),UV/TiO2/H2O2 treatment supported the highest pollutant removal, COD removal, and dechlorination efficiencies followed by UV/TiO2 and UV/H2O2. The remaining toxicity to Lipediurn sativurn was similar after all pre-treatments. Chlorophenol photodegradation was always well described by a first order model kinetic (r(2) > 0.94) and the shortest 4CP, DCP, TCP and PCP half-lives of 8.7, 7.1, 4.5 and 3.3 h, respectively, were achieved during UV/TiO2/H2O2 treatment. No pollutant removal was observed in the controls conducted with H2O2 or TiO2 only. Inoculation of all the photochemically pre-treated mixtures with activated sludge microflora was followed by complete removal of the remaining pollutants. Combined UV/TiO2/H2O2-biological supported the highest detoxification, dechlorination (99%) and COD removal (88%) efficiencies. Similar results were achieved when each chlorophenol was supplied at 100 mg l(-1). COD and Cl mass balances indicated UV, UV/H2O2, and UV/TiO2 treatments lead to the formation of recalcitrant photoproducts, some of which were chlorinated. (c) 2006 Elsevier Ltd. All rights reserved.


  • Tamer Essam
  • Magdy Aly Amin
  • Ossama El Tayeb
  • Bo Mattiasson
  • Benoit Guieysse
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Environmental Sciences


  • hazardous pollutants, advanced oxidation processes, biodegradation, industrial wastewater, photodegradation
Original languageEnglish
Pages (from-to)2201-2209
Issue number11
Publication statusPublished - 2007
Publication categoryResearch