In this paper, an experimental investigation on the effect of parameters namely concentration, solar radiation intensity and exposure time on the photo oxidation of pollutants in secondary treated municipal wastewater has been presented. TiO₂ was used as the photo catalyst and the experiments were carried out in the month of February 2012 in Oman. The reactor was a glass tube constructed with the provision of adding a reflector. The results showed that photo catalytic treatment is very effective for dilute solutions and the presence of reflector enhances the photo degradation. The reduction in Chemical Oxygen Demand (COD) obtained at the experimental conditions of 0.007 m³/hr flow rate, 15° inclination angle and 1 g·L^-1 TiO₂ dosage was 18%. The presence of the reflector increased the degradation to 25% at the above experimental conditions.