Study of the wavelength effect in the photolysis and heterogeneous photocatalysis

In this work, photocatalytic and photolytic degradation of two model pollutants has been done. The chosen substances were 2,4-dichlorophenol (DCP) and sulfamethoxazole (SMOX), both with different absorptive properties in the UV range. The experiments were carried out under UV-A and concomitant UV-ABC radiation, studying the effect of each type of radiation on each type of degradation. Different kinetic orders were applied to the experimental series, results were fitted to the time and incident radiation. Also, the photon flow absorbed by the suspension and the quantum yield was measured for each condition tested. It was found that UV-ABC radiation can be more efficient than UV-A, although it depends also on the properties of the pollutant. It was demonstrated that the plotting of compounds degradation versus the incident UV radiation offers more accurate perspectives in establishing comparisons between different radiation sources. In this way, the conclusions are very similar to those obtained calculating the quantum yield, which is probably one of the best options to analyze a process.