Study on the photocatalytic degradation of styrene using TiO2 nanocatalyst

In the present study, photocatalytic degradation of styrene was evaluated using nano TiO2 (Degussa P-25) as a catalyst. The experiments were conducted in a slurry batch reactor equipped with three UV lamps. Determinations of styrene concentrations were done by HPLC. Preliminary tests were made to determine the necessary contact time to reach the adsorption equilibrium. In addition to photocatalysis, separate photolysis experiments were conducted but showed low efficiency. For the photocatalysis experiments, the effects of the styrene initial concentration were evaluated, as well as, the catalyst concentration and the initial pH of the solution. The experimental results showed that in 125 min, 99% of the initial styrene was degraded by photocatalysis. It was verified that the styrene degradation rate fits a pseudo-first-order kinetics for initial styrene concentrations (100-200-300 ppm), at 25 °C. Optimal experimental conditions for arbitrary aqueous styrene concentration (100 mg L−1) were found initial pH 6 and TiO2 loading 1.0 gL−1.