1,4-Dioxane, is a synthetic organic compound used widely throughout industry as a solvent. 1,4-Dioxane causes liver damage and kidney failure and has been shown to be carcinogenic to animals, and is a potential carcinogen to humans. Its recalcitrant nature means that conventional water treatment methods are ineffective in removing it from water. A class of technologies called advanced oxidation technologies has been shown to completely mineralise 1,4-dioxane. In this study the effects of pH on TiO2 photocatalysis reactor systems were investigated. pH was found to significantly affect the efficiencies of these processes with neutral pH conditions the most effective. (C) 2010 Elsevier B.V. All rights reserved.