The elimination of 1, 2, 7, 8-etrachlorodibenzo-p-dioxin by catalytic hydrodechlorination

Polychlorinated dibenzo-p-dioxins/furans (dioxins) are a kind of carcinogens and important persistent organic pollutants (POPs). In order to reduce the harm to environment and humans, it is necessary to develop an effective method to eliminate and reduce dioxins. Dechlorination is an efficient means to eliminate the toxicity of dioxins. In this paper, using H₂ as a hydrogen donor, 1,2,7,8-tetrachlorodibenzo-p-dioxin (1,2,7,8 TCDD) was catalytically hydrodechlorinated when Pd/C (5%) and alpha propylene glycol/ water (1:1) were selected as catalyst and carrier solvent respectively. The effects of some factors such as the initial concentration, reaction temperature and concentration of catalyst on catalytic hydrogenation reaction of 1,2,7,8-TCDD were discussed. The results showed 1,2,7,8-TCDD could be eliminated efficiently when the reaction temperature was 45°C, the concentration of catalyst was about 0.5 gml^-1. The data suggested that the catalytic hydrodechlorination was a useful technology to eliminate and reduce the toxicity of dioxins.