Chemistry Reference
In-Depth Information
19
Photocatalytic Treatment of Laboratory
Wastes Containing Hazardous
Organic Compounds
Edmondo Pramauro, Alessandra Bianco Prevot and Debora Fabbri
Department of Analytical Chemistry, V. Pietro Giuria 5, Torino, Italy
19.1 Photocatalysis
The problems related to the elimination of hazardous substances present in liquid wastes are of great interest, not
only for people directly involved in industrial and agricultural activities, but also for the chemists operating in
control laboratories, where more or less abundant stocks of toxic wastes are usually accumulated and/or produced.
The two main sources of wastewaters coming from the analytical laboratory are the residual samples
stored after the analysis and the wastes arising from the application of the analytical protocols. In the first
case the volume of samples taken from contaminated waters, from effluent generated by the industrial
production and from a variety of other human activities could be relevant, whereas in the second case the
volume of solutions containing dangerous products directly produced during the application of the analytical
method is generally lower.
Taking into account that the storage and disposal of all these effluents is usually difficult and costly, the
direct treatment of such wastes in the laboratory could be of practical interest in order to reduce the dangerous
products content below the limits admitted by the law regulations.
In this direction the so called advanced oxidation process (AOP) could represent a promising approach
and an interesting alternative to other traditional wastewater treatments, being particularly attractive for
degradation of organic pollutants and their transformation into non toxic or less toxic products. Among these
techniques, heterogeneous photocatalysis is one of the most interesting treatments since it operates at mild
conditions of temperature and pressure and it is able to perform the complete mineralization of a great variety
of organic harmful species present in different aqueous matrices [1-5].
