Abstract
This paper investigates the treatment of water samples contaminated with 2, 4, 6-trichlorophenol (TCP) by gamma radiation. The effects of absorbed dose, initial pH, and chloride ions on the removal of TCP were investigated. In addition, the individual and combined effects of gamma irradiation and ozonation on the toxicity of TCP solutions were assessed. The results showed that the complete decomposition of TCP could be attained at 3.5 kGy in good agreement with previous studies. The pH of the solutions was found to affect the efficiency of the treatment, and the optimal removal of TCP was observed at pH 4.0. The addition of chloride ion to TCP solution before irradiation enhanced the removal% up to 46% depending on the absorbed dose and chloride ion source. Toxicity measurements indicated that the absorbed dose required for the detoxification was ca. 20 × higher than that required for TCP decomposition. The combination of gamma irradiation with ozonation enhanced the detoxification of TCP, and a synergistic effect was observed. This synergistic effect increases with the ozonation time and absorbed dose and led to a significant reduction in the absorbed dose required for a complete detoxification from 70 to 35 kGy.
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•Detoxification of TCP was investigated by γ-irradiation and ozonation.•TCP can be converted by AOPs to more persistent and toxic by-products.•Chloride ion enhanced the removal of TCP by γ-irradiation up to 46%.•Ozonation alone did not enhance the detoxification of TCP or its by-products.•The combination of ozonation and γ-irradiation enhanced the detoxification of TCP.