Photocatalytic degradation of organic pollutants and detection of chemical oxygen demand by fluorescence methods

TiO2 photocatalyst was used to degrade organic pollutants in aqueous solutions and the detection of chemical oxygen demand was studied by fluorescence method. It was found that TiO2 dosage, initial solution pH, initial concentration electron acceptor Ce4+, the time of UV light irradiation and the temperature of solution affected the degradation of the organic pollutants. The optimum conditions were obtained at amounts of TiO2 1.0 g l−1, pH 0.38, Ce4+ 6.0 mmol l−1, time 10 min and temperature 80 °C, respectively. The produced Ce3+ was determined by fluorescence method, with the maximum excitation and emission wavelengths at 264.8 and 362.1 nm, respectively. The fluorescence intensity was linear with COD in 0∼100.0 mg l−1. The limit of detection was 0.9 mg l−1. This method was applied in detection of COD in samples of lake water and simulate sewage.