Observations of 2,4,6-trichlorophenol degradation by ozone.
The aqueous reactivity of 2,4,6-trichlorophenol (TCP) with ozone has been studied at laboratory-scale using a simple gas bubble/liquid contacting system. Degradation rate constants were measured directly and found to be 7.6 and 77.2 M(-1)s(-1) at pH 2 and 7.5, respectively. At pH 7.5, 10 min of ozonation ( identical with 15 mM ozone consumption) achieved a 90% degradation of TCP, which corresponded to the release of approximately 2 mol Cl(-) per mol TCP. The presence of hydrogen peroxide in solution did not significantly increase the TCP degradation but increased the overall dechlorination to 2.7 mol Cl(-) per mol TCP. The presence of humic acid (HA) in solution was found to enhance the degradation rate of TCP at low relative HA concentrations (<0.6 g/g HA:TCP), but to reduce the rate at higher HA concentrations.
Graham
Nigel
N
Department of Civil and Structural Engineering, Research Centre for Urban Environmental Technology and Management, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Chu
Wei
W
Lau
Catherine
C
D002733:Chlorophenols / Q000737:chemistry*; D004787:Environmental Pollution / Q000517:prevention & control*; D006812:Humic Substances / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009153:Mutagens / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry; D010083:Oxidants, Photochemical / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*
D002733:Chlorophenols; D006812:Humic Substances; D009153:Mutagens; D016877:Oxidants; D010083:Oxidants, Photochemical; D010126:Ozone; D006861:Hydrogen Peroxide; C024564:2,4,6-trichlorophenol