P. Zawadzki, E. Kudlek, M. Dudziak
Silesian University of Technology, Institute of Water and Wastewater Engineering, Gliwice, PL
INFLUENCE OF THE PHOTOCATALYST TYPE AND PH OF SOLUTION ON PHOTOCATALYTIC DEGRADATION EFFICIENCY OF BISPHENOL A
In this study the photocatalytic degradation of bisphenol A in the presence of titanium dioxide (TiO2) and own modified photocatalysts (composites) based on TiO2, activated carbon and methanol (TiO2-AC) were investigated. The effect of initial pH (4–7) of model solution were determined in order to adsorption effectiveness and decomposition of tested micropollutant under ultraviolet (UV) irradiation. Based on chromatographic analysis (HPLC) results it was found that the decomposition of bisphenol A was higher for modified photocatalysts than for commercial TiO2. It was possibly associated with the presence of activated carbon, which is not only a support for photocatalysts but also increases the adsorption capacity. The surface properties of composite were characterized also by scanning electron microscopy (SEM). Based on the Langmuir-Hinshelwood (L-H) model, the kinetic parameters of the photocatalysis process were carried out. According to the pseudo first-order parameters, the results showed that the decomposition of bisphenol A was most intensively in the first 15 minutes of the process. However the value of the k rate was higher for modified photocatalysts than for commercial TiO2. No significant effect of pH on adsorption and BPA decomposition in the presence of commercial titanium dioxide were observed. Whereas, both the sorption and photocatalysis carried out in the presence of modified photocatalysts depended on the pH of model solution. The highest degree of bisphenol A decomposition were observed by irradiating mixture at pH 4.
Keywords: bisphenol A, photocatalysis, modified photocatalysts, titanium dioxide, activated carbon