Advanced oxidation technologies industrial applications

The use of advanced oxidation processes (AOPs) to remove pollutants in water treatment applications has been widely studied and applied industrially, but it is still an area of active development. New problems derive from toxic, refractory and xenobiotic micropollutants and the increasing requirements in terms of energy efficiency and quality of water in several industrial wastewater streams. This chapter introduces the AOP technologies and discusses the possibilities offered by using catalysts in these methods, with selected examples regarding the industrial applicability of these AOPs and open questions about their further development. 

We have presented here a general view of the different AOPs and discussed the possibility of their improvement using solid catalysts, selecting some representative examples regarding the industrial applicability of these advanced oxidation processes and highlighting unanswered questions to be addressed in their further development. However, not all the possible technologies and their combinations have been discussed, due to space constraints. In particular, the use of electrochemical methods (from anodic oxidation to electro-Fenton, electrocatal3rtic, and photoelec-trocatalytic processes) has been not discussed. Some consideration of these can be found in reviews. 

Different aspects of total oxidation processes are reviewed in the first part of the book hydrocarbon oxidation (Chapter 1) and soot oxidation (Chapter 2) for mobile appficafions while oxidation of volatile organic compounds (VOC) is treated in the next five chapters. Chapter 3 provides a general overview of VOC oxidation while chlorinated VOCs are specifically discussed in Chapter 4 and persistent VOC in Chapter 5. Plasma catalysis processes for VOC abatement are reviewed in Chapter 6. Finally, Chapter 7 gives the point of view of industry for the development and applications of catalysis for air depollution technologies. Total oxidation is also used for energy production by combustion processes exemplified in Chapter 8. The last two chapters are devoted to oxidation processes in liquid media by electrochemical techniques (Chapter 9) or more generally as "advanced oxidation processes" for water depollution (Chapter 10). 

Lutetium is also a very rare metal, with a world production (as lutetium oxide) of approximately 10 tons per year. One commercial application is known it is used as a P-emitter, (when Lu-176 has been exposed to neutron activation) in the oil refining industry (Emsley 2001). It was used in so-called-bubble memory, a technology for computer memory that has become obsolete, since hard disks have made their rapid substantial advance. It is still used in scintillation crystals for PET-scanners (positron emission scanners). It is used here in the form of cerium-doped Lutetium oxy-orthosilicate (LSO), with the formula Ce2x Lu2(l — x) SiOs, where x is within tire range from approximately 2 x 10 to approximately 3 X 10 (Melcher 1990 Daghighian et al. 1993). 

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