AOPs and AOTs

This book concentrates on the basic principles, reaction mechanisms and engineering concepts of technologies that use UV radiation (or light) as a selective reagent for the cleavage of chemical bonds and hence for the destruction of unwanted chemicals or microorganisms. Accordingly, these methods include UV 

Air quality guidelines, drinking water quality, water resources World Health Organization (WHO) h ttp / / ww w. wh o. int/home-page 

Bibliography on heterogeneous photocatalysis National Renewable Energy Laboratory http //www.ott.doe.gov/coolcar/ pdfs/water air2.pdf 

Chemical nomenclature International Union of Pure and Applied Chemistry http //WWW. iupac. org 

Chemical structure database, structure viewing support by Chemscape Chime U.S. National Library of Medicine, National Institute of Health http //sis.nlm.nih.gov/Chem/ ChemMain.html 

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Tab. 2.3 Selected historical landmarks related to the development of AOPs and AOTs and their mechanisms...

The most important water treatment technologies are summarized in Fig. 5-6. Depending on the source and on the water quahty, either mechanical, biological, physical, thermal, or chemical processes or their combinations may be applied. Photochemical AOPs and AOTs are subordinated to chemical processes, mainly because the current technological versions of photochemical wastewater remediation are dependent on the addition of auxihary oxidants, such as hydrogen peroxide, ozone or special catalysts such as titanium dioxide. Photochemical AOPs are attractive alternatives to non-destructive physical water treatment processes, for example adsorption, air stripping or desorption and membrane processes. The last merely transport contaminants from one phase to another, whereas the former are able to minerahze organic water contaminants (cf. Chapter 1). 

Many research activities in the field of AOPs and AOTs are related to photoreactor development, reactor modeling, optimization and scaling-up of photoreactors. Several recent examples are collected in Tab. 8-1. 

However, this collection of literature has to be extended to include several important recent contributions to the fields of photochemistry, photochemical AOPs and AOTs. For example, the text book by Suppan (1994) covers the basic principles of various UV and light induced processes in different research areas and demonstrates in an excellent manner the interdisciplinary applications and potentials of photoscience. This is also emphasized by Bottcher et al. (1991) who concentrate on several important technical applications using UV/VIS radiation as a reagent, an information carrier and as an energy carrier. Unfortunately, these authors hardly mention the expanding field of photochemical AOTs for waste treatment. 

A significant new group of methods to improve disinfection has recently emerged under the banner of advanced oxidation technology (AOT) or advanced oxidation processes (AOP) (ComnineUis et aL, 2008 Joseph et al, 2009 Oiler et al, 2011 Sievers, 2011). This may be divided into chemical AOP and photochemical AOP (Tunay et ai, 2010). 

Fig. 2.2 The dirty dozen of persistent organic pollutants (POPs) and effects of photo-initiated processes (and of AOPs/AOTs in general) generating a convenient sink.

The evaluation of the AOP treatment costs represents a very critical aspect. The overall costs of an AOT are composed of capital costs, the operating costs (including auxiliary oxidants and all other supplementary chemicals) and the costs of... 

Professor Oppenlander is well qualified to write about AOPs/AOTs, since he has contributed to this literature in a very significant manner. It is thus particularly valuable to see the application of incoherent excimer lamps covered so well, a subject that has been a central part of his research. Finally, it is good to see careful attention being made to consistent terms, definitions and units in accord with lUPAC recommendations. 

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