AbstractOne of the most important environmental concerns is that of water contamination from industrial effluent and dyes used in the textile industry are a primary cause of such contamination. Most conventional methods of wastewater treatment are insufficient to remove these pollutants, so tests were done on a method of removing acid red 4092 dye from wastewater. Tests investigated advanced oxidation processes, based on hydroxyl radical production, were used as an effective method to remove this type of pollutant. The purpose of this study was to investigate the removal of acid red 4092 dye by zinc oxide nanoparticles and ultraviolet radiation (UV-150 W). Dye concentration was measured before and after treatment using a spectrophotometer (Perkin–Elmer Lambada 25–UV/vis). Experiments were performed in a batch photo-reactor on synthetic wastewater with concentrations of 0.5, 1.0, 1.5, and 2 mg/L. The study investigated the effects of factors such as initial dye concentration, irradiation time, dose of cata...