Fixed-bed reactor packed with pumice-supported TiO₂ for the treatment of polluted water by solar-driven photocatalytic oxidation

Abstract

A bench-scale tubular photo-reactor was built to evaluate the solar-driven TiO₂–based photocatalytic degradation of synthetic polluted water samples. The reactor was designed as a compound-parabolic-collector and operated in batch mode using TiO₂ P25 immobilized on a bed of pumice. The immobilization of TiO₂ on pumice was carried out using a facile dip impregnation method followed by heat treatment. The obtained material was characterized by SEM, EDS, XRD, and nitrogen adsorption. It was possible to impregnate up to 68.5 mg of TiO₂ per gram of pumice stones of 8–14 mm. Conversions of up to 35–40 and 62–69%, after 4 h of treatment and UV doses of 20.8 ± 3.5 kJ L⁻¹, were achieved when the catalyst was used immobilized on pumice stone and in the form of a suspension, respectively. The stability and reusability of the catalyst–coated support was tested through a series of consecutive photocatalytic experiments. After four consecutive runs, the immobilized catalyst showed a decrease in its photoactivity leading to removal levels of 23%.

Keywords:

• Compound parabolic collector
• fixed-bed reactor
• photocatalysis
• solar reactor
• supported catalyst
• titanium dioxide

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data availability statement

The data that support the findings of this study are available from the corresponding author, D.H. Quiñones, upon reasonable request.

Additional information

Funding

This work was supported by the Universidad del Atlántico. The authors greatly acknowledge all the technical and financial support provided by the Universidad del Atlántico for this project.