Arising from the persistence and toxicity, halogenated organic compounds (HOCs), which account for a large part of emerging contaminants, have caused a worldwide concern. However, their efficient total degradation/detoxification is still a major challenge currently. The newly developed sulfite/UV process showed high efficiency in removal of twenty-one kinds of aliphatic and aromatic HOCs selected (substituted by Cl, Br, and I), including seven haloacetic acids, eleven halophenols, and three halobenzoic acids. Total dehalogenation was also achieved within minutes, and the kinetics increased with the ascending order of Cl < Br < I substitution as well as the increased halogenation degree. The degradation mechanism was further studied. While the direct photolysis made big contributions to the aromatic HOCs degradation, the hydrated electron (eaq-) produced during the photoionization of sulfite was significantly more responsible for the aliphatic HOCs dehalogenation. The eaq--exposure was consequently quantified according to the modeling study of monochloroacetic acid dechlorination. The energy efficiency in terms of EE/O was provided for the reductive dehalogenation in the natural surface water. These results suggest that sulfite/UV is a promising method for the efficient removal and detoxification of recalcitrant contaminants.

Efficient total dehalogenation of aliphatic and aromatic halogenated compounds by the sulfite/UV process

248th National Meeting (2014)

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