15
Figure 1. Diagram of pilot plant (Doll & Frimmel :2005)
The combination of TiO
2
with cross-flow microfiltration accompanied by periodical back-wash was
investigated in the above pilot plant setup. The investigation included the testing of membrane material
because the membrane must resist the abrasion and the periodic back-wash. The potential of two different
TiO
2
materials (Hombikat UV100 and Degussa P25) had been evaluated. The investigations showed that
the photocatalytic activity of P25 and Hombikat UV100 was constant during continuous usage over
several days.
Over the years, studies on the application of photocatalytic degradation process were still in pilot plant or
lab scale. More efforts have to be put in to commercialize the process. These should come from
researchers' efforts and government's focus on the chronic effects of pharmaceutical and fine chemicals
waste.
REFERENCES
Bhatkhande, D.S., Pangarkar, V.G. and Beenackers, A.ACM. 2001. "Photocatalytic degradation for environmental
applications a review". Journal of Chemical Technology and Biotechnology. Vol. 77, pp. 102-116.
Doll, T.E., and Frimmel, F.H. 2005. "Cross-flow microfiltration with periodical back-washing for phtocatalytic
degradation of pharmaceutical and diagnostic residues evaluation of the long-term stability of the
photocatalytic activity of TiO
2
". Water Research. Vol. 39, pp. 847-854.
Fujishima, A. and Rao, T.N. 1997. "Recent advanced in heterogeneous TiO
2
photocatalysis". Prcoceedings
Chemical Science (Indian academic Science). Vol. 109, No. 6, pp. 471-486.
Hofstadler, K., Bauer, R., Novalic, S. and Heisler, G. 1994. "New reactor design for photocatalytic wastewater
treatment with TiO
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immobilized on fused silica glass fibers: photomineralization of 4-chlorophenol".
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Ternes, T.A. 1998. "Occurrence of drugs in German sewage treatment plants and rivers". Water Reserach. Vol. 32,
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Ternes, T.A., and Hirsch, R. 2000. "Occurrence and behavior of X-ray contrast media in sewage facilities and the
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Ternes, T.A., Meisenheimer, M., McDowell, D., Sacher, F., Brauch, H-J., Haist-Gulde, B., Preuss, G., Wilme, U.,
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