The sensitization effect of waste toner powder in the photocatalytic degradation of surfactant sodium dodecylbenzene sulfonate over immobilized TiO2–chitosan layer under UVC and solar irradiation

Abstract

The application of dye sensitized photocatalysis for the degradation of surfactant in the model wastewater has been studied. The aim was to explore the possibility of the photocatalytic activity enhancement by introducing the waste toner powder in the photocatalytic films. The development and a partial characterization of the supported catalyst were described within this study. Waste toner and commercial TiO2 powder (AEROXIDE® P25) were integrated within the matrix of chitosan molecules as a thin layer films. The developed films contain the high amount of the TiO2 (approx. 90%) which structure appeared to be intact. The efficiency of the photocatalytic films for the oxidation of the anionic surfactant dodecylbenzene sulfonate (SDBS) has been evaluated. Preliminary experiments were performed in an annular batch reactor using UVC lamp. Photocatalytic films were supported on the glass, stainless steel and waste offset printing plates. Support was made in a form of plates or rings. Further experiments were performed under artificial and natural solar irradiation whereby photocatalytic films were fixed at the bottom of reaction cell (boat shaped flow reactor). In order to estimate the reaction rate constant for SDBS degradation over irradiated photocatalytic films and to evaluate the effects of photon absorption under different irradiation conditions, a detailed kinetic model was developed. The sensitization effect of the components in toner powder due to the visible light absorption for the photocatalytic oxidation of SDBS under solar irradiation was quantified.