Degradation of chlorophenols in aqueous media using UV XeBr excilamp in a flow-through reactor

2-Chlorophenol (2-CP), 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) at initial concentrations of 10, 20, 50 and 100 mg l−1 were degraded in aqueous media by direct UV photolysis using dielectric barrier discharge XeBr∗ excilamp (283 nm) in a flow-through photoreactor. The pseudo-first order rate constants were highest and half-life times were lowest for 4-CP. The rates of photolysis under the experimental conditions increased in the order: 2-CP < 2, 4-DCP < 4-CP. The intermediates of photolysis were identified by GC–MS and HPLC. The evolution of hydroquinone and p-benzoquinone as major intermediates of 4-CP photolysis was monitored.