1,3-dinitrobenzene (m-DNB) is one of the compounds released to water in discharges during the manufacture of explosives. Its widespread distribution as an environmental contaminant is a potential threat to wildlife and other ecological receptors. Therefore, removal of m-DNB from aqueous solution is very important. In this work, which is a continuation of our ongoing investigation of the effect of various functional groups in aromatic derivatives, a study of the destruction of m-DNB in aqueous solution, was carried out using both concentrated solar radiation and artificial UV radiation. It was found that a variety of phenolic intermediates are formed via hydroxyl radicals attacking the parent compound. The effects of the various parameters such as adsorption, initial concentration, catalyst loading, pH and anions on the photocatalytic degradation of m-DNB was studied. The kinetics of the photocatalytic reaction were also studied. The effect of the second nitro group in m-DNB was elucidated by comparison with our earlier work on PCD of nitrobenzene. (c) 2005 Society of Chemical Industry