Photochemical degradation of Quinoline (Qu), was investigated using lowpressure UV light irradiation in the presence of persulfate (S2O8 2−) in a rectangular photoreactor at experimental condition. S2O8 2− and UV light showed negligible effect when they were used independently. Removal efficiency of Qu was sensitive to the operational parameters such as initial concentration of the oxidants, initial concentration of Qu and initial pH. Under the optimum conditions of [S2O8 2−] = 1000 mg/L, [Qu]0 = 40 mg/L and pH = 6 about 97.3% Qu degradation was achieved after 100 min treatment. Also total organic carbon (TOC) content removal was obtained 31.6% after 120 min. For kinetic study, the HPLC analysis was used in which the concentration of Qu in the employed process was followed. Rate of Qu degradation in this process is completely in line with pseudo-first-order kinetic model. In addition, the rate constant related to QU degradation under optimum conditions was 0.0247 min −1. The role of active radicals was studied using radical scavengers of ethanol and tert-butyl alcohol, indicating the contribution of hydroxyl and sulfate radicals in degradation about 60% and 40%, respectively. In performance evaluation, the required electrical energy for nearly complete degradation of Qu was obtained. Electrical energy consumption and cost were 155.46 kWh/m3 and 10.88 $/m3, respectively.