Advanced oxidation processes (AOPs) offer a promising alternative to classical treatment methods (e.g., adsorption, flocculation, and air stripping) of treating water and wastewater. AOPs are able to treat pollutants more efficiently by completely mineralizing them to more stable species of carbon dioxide, water and inorganic ions. The operational parameters influencing the photocatalytic degradation rate of methylene blue in dye polluted wastewater treatment were studied. These parameters are initial dye concentration, catalyst concentration, H₂O₂ volume. The catalysts used were titanium dioxide (TiO₂), Hydrogen peroxide (H₂O₂) in all experiments to increase the efficiency of the UV/TiO₂ process. The experiments of UV-lamp revealed that the best removal is 67.37% when using 1.5-gram TiO₂/L of pollutant solution, but in the solar UV experiment the best removal is 99.09% when using 1 gram of TiO₂/L of pollutant solution. The effect of initial dye concentrations on the photocatalytic degradation showed the limits of concentrations which can be removed easily, 5 ppm gave the best results of pollutant degradation. Addition of H₂O₂ to the pollutant stream improved the photocatalytic degradation of pollutant. The effect of different flowrates on the photocatalytic degradation showed the best flow rate was 500 ml/min which should be used to achieve the best results.