Sonophotocatalytic degradation of poly (vinyl pyrrolidone) (PVP) in the presence of TiO2 nanoparticles

The degradation of poly (vinyl pyrrolidone) (PVP) by means of ultrasound irradiation and itscombination with heterogenous photocatalysis (TiO2 nanoparticles) was investigated. Emphasiswas given on the effect of additive on degradation rate constants. 24 kHz of ultrasoundirradiation was provided by a sonicator, while an ultraviolet source of 30 W was used for UVirradiation. To increase the efficiency of degradation process, degradation system was combinedwith TiO2 nanoparticles (0.1-0.6 g L-1) in the presence of UV irradiation. Sonophotocatalyticprocess led to complete PVP degradation in 150 min with the rate increasing with increasingcatalyst loading. Sonophotocatalysis in the presence of nanoparticles was always faster than therespective individual processes. A synergistic effect between ultrasound and ultravioletirradiation in the presence of TiO2 nanoparticles was suggested. The average molecular weightof ultrasonicated PVPs was determined by measurements of intrinsic viscosity of samples.