Journal of Chemical Technology and Biotechnology, Vol.88, No.12, 2181-2187, 2013
Removal of 2,4-dichlorophenol by aluminium/O-2/acid system
BackgroundAlthough the oxidative removal of organic compounds by the Al/O-2/acid system has been previously studied, the in situ generation of reactive oxygen species (ROS) and its influencing factors are not well understood. 2,4-dichlorophenol (2,4-DCP) is one of the priority control pollutants and widely present in the environment. In this study, the oxidative removal of 2,4-DCP by the Al/O-2/acid system was investigated, especially the in situ generation of ROS and influencing factors. ResultsMore than 90% of 2,4-DCP was removed within 10 h in pH 2.5 solutions initially containing 10 g L-1 Al and 8.25 mg L-1 dissolved oxygen. The removal of 2,4-DCP was acid and oxygen driven and was accompanied by the release of chloride ions. While the reduction of oxygen to H2O2 by Al was obtained only under conditions of pH < 4.0, the subsequent Al-mediated transformation of H2O2 to center dot OH was achieved under pH < 5.0 conditions. Furthermore, five primary intermediates were identified and oxidation pathways of 2,4-DCP by the Al/O-2/acid system were proposed. ConclusionsThis work describes a potential method for the removal of 2,4-DCP in aqueous environments. Oxygen levels and solution pH played important roles in the removal of 2,4-DCP by Al/O-2/acid system. (c) 2013 Society of Chemical Industry
Keywords:2,4-dichlorophenol;reactive oxygen species;advanced oxidation process;zero valent aluminum;zero valent iron