Photocatalytic detoxification with the thin-film fixed-bed reactor (TFFBR)

Clean-up of highly polluted landfill effluents using a novel TiO₂-photocatalyst

authored by

M. Bekbölet, M. Lindner, D. Weichgrebe, D. W. Bahnemann

Abstract

Two different photocatalysts, namely Hombikat UV100 (Sachtleben Chemie) and P25 (Degussa) have been used in batch experiments to compare their ability to degrade the toxic components of a biologically pretreated landfill leachate. A strong adsorption of the pollutant molecules was observed for both TiO₂-powders, with a maximum of almost 70% TOC reduction for Hombikat UV100, making it almost impossible to draw a quantitative comparison of the degradation with the two catalysts in the batch system. The photocalytic activity of Hombikat UV100 was also tested using a thin-film fixed-bed reactor (TFFBR) configuration under artificial solar UV-irradiation. Here the catalyst was fixed onto a glass-plate to avoid separation of the catalyst and water after the treatment. The highest degradation rate was observed at pH 5, using a moderately diluted waste water. In good agreement with the degradation rate's pH dependency adsorption measurements showed a maximum adsorption of the organic pollutants onto Hombikat UV 100 TiO₂ at pH 5. Photonic efficiencies (ζ) based on the amount of incident irradiation have been calculated for the experiments, ζ could be increased by a reduction of the light intensity. While the addition of H₂O₂ had an inhibiting effect (at pH 7), the presence of Na₂S₂O₈ led to a dark reaction. Studies performed under continuous recirculating conditions showed that even undiluted waste-water streams can, in principle, be degraded completely.

External Organisation(s)

Bogazici University
Institute for Solar Energy Research (ISFH)
Clausthal University of Technology

Type

Article

Journal

Solar Energy

Volume

56

Pages

455-469

No. of pages

15

ISSN

0038-092X

Publication date

05.1996

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Renewable Energy, Sustainability and the Environment, Materials Science(all)

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1016/0038-092X(96)00020-5 (Access: Closed)