PROPHIS: parabolic trough-facility for organic photochemical syntheses in sunlight.

The PROPHIS facility is an efficient tool for the synthesis of chemicals with moderately concentrated sunlight on a semi-technical scale. The feasibility of selected solar photochemical reaction classes--including heterogeneous and homogeneous reactions--has been demonstrated using various set-ups of the plant. This paper outlines the potential of solar photochemistry by representative examples.

Paper mill wastewater detoxification by solar photocatalysis.

In the WATER project the German Aerospace Center, and the Universidade Federal de Uberlândia, analyse the possibilities of treating paper mill effluents by solar photocatalysis for the paper mill of the Brazilian paper producer Votorantim Celulose e Papel, VCP, at Luiz Antônio, SP, Brazil. The degradation of the bio-polymer lignin is a vast problem in paper production. The tests have shown that treatment by the photocatalyst TiO2 and solar radiation is an ecological future oriented approach to solve this problem.

A comparison of prototype compound parabolic collector-reactors (CPC) on the road to SOLARDETOX technology.

Solar photocatalytic detoxification of non-biodegradable chlorinated hydrocarbon solvents (NBCS) is carried out in different concentrating and non concentrating devices using TiO2 as a photocatalyst fixed on the inner surface of the reaction tubes or as a slurry catalyst which has to be removed from the treated water. The reaction is most effective using 200 mg/l of TiO2 as a slurry in a non concentrating CPC reactor. The concentrating parabolic trough reactor has a poor activity because of its minor irradiated reactor surface.

Systematic study of parameters influencing the action of Rose Bengal with visible light on bacterial cells: comparison between the biological effect and singlet-oxygen production.

As part of a project to study different methods for the disinfection of effluent water, the inactivation of different microorganisms (Escherichia coli, Deinococcus radiodurans and spores of Bacillus subtilis) using a combination of a photosensitizer (Rose Bengal) with simulated sunlight and oxygen was determined under various environmental conditions (temperature, pH index). In parallel, the singlet-oxygen (1O2) production was also measured under the same conditions. Whereas the vegetative cells could be inactivated much more efficiently at increased temperature and altered index of pH, the production of 1O2 remained essentially the same under these alterations.