inorganic chemistry

Environmental photosensitization processes may be stimulated
not only by natural but also by anthropogenic pollutants, such as
phenols and dihydroxybenzenes, which are efficient
photosensitizers. Among others, phenol was found to sensitize
the dehalogenation of halogenophenols( 268 ). This behavior shows
that the simultaneous presence of the adequate sensitizer and
quencher in polluted environment can lead to the photosensitized
decomposition of the latter and thereby to pollution abatement.
One of the most relevant activators is traces of solid
semiconductors present in atmospheric or hydrospheric com-
partments. This role may be played not only by typical
semiconductors but also by many different substances even des-
sert sand and volcanic ash( 23 – 25,269– 271 ).
The self-cleaning mechanisms by photocatalysis and photosen-
sitization apply also to organic matter included in
microorganisms, thus it can also lead to environmental self-dis-
infection. This is especially expected in the vicinity of a semicon-
ductor (especially TiO 2 ) and/or iron deposits, which are
responsible for solar photogeneration of reactive oxygen
substances capable of water disinfection( 272 – 275 ).

ACKNOWLEDGMENTS

The technical assistance of Mr. Zygmunt Wołek in preparation
of the chapter is greatly appreciated.

REFERENCES

1. Shichi, T.; Takagi, K.J. Photochem. Photobiol. C. Photochem. Revs.2000,
   1 , 113.


2. Ciesla, P.; Kocot, P.; Mytych, P.; Stasicka, Z.J. Mol. Catal. A. Chem2004,
   224 , 17.


3. Balzani, V.; Bergamini, G.; Campagna, S.; Puntoriero, F. In“Photochem-
   istry and Photophysics of Coordination Compounds I”Vol. I;. In: Eds.
   Balzani, V.; Campagna, S. Verlag: Berlin, 2007 , p. 1.


4. Gaffney, J. S.; Marley, N. A.; Clark, S. B. In“Humic and Fulvic Acids”;
   ACS Symposium Series,,1996,Vol. 651, p. 2.


5. Rey-Castro, C.; Mongin, S.; Huidobro, C.; David, C.; Salvador, J.;
   Garces, J. L.; Galceran, J.; Mas, F.; Puy, J.Environ. Sci. Technol.2009,
   43 , 7184.


6. Boule, P.; Bolte, M.; Richard, C. In:“Environmental Photochemistry”; Ed.
   Boule, P.; Springer: Berlin, 1999 , p. 181.


7. Rontani, J. F. In: “Environmental Photochemistry”; Ed. Boule, P.;
   Springer-Verlag: Berlin, 1999 , p. 263.


8. Larson, R. A.; Marley, K. A. In:“Environmental Photochemistry”; Ed.
   Boule, P.; Springer: Berlin, 1999 , p. 123.

334 ZOFIA STASICKA