<p>Photocatalytic degradation of tetrahydrofuran, 1,4-dioxane, and their mixture in a slurry photoreactor was studied. Using both GC/MS and ion chromatography (IC) methods, possible intermediates were detected and the reaction mechanism pathways for both compounds were proposed. Kinetic models were developed and the kinetic parameters were estimated using a statistical method of non-linear parameter estimation in which all experimental data were utilized. It was shown that tetrahydrofuran was disappeared via direct oxidation as well as hydroxyl radical attack. A modified Langmuir-Hinshelwood described the degradation behavior of tetrahydrofuran and the binary system. 1,4-Dioxane obeyed a simple Langmuir-Hinshelwood kinetic form in the single compound system. </p>