Advanced oxidation-biological processes

Keywords Advanced oxidation-biological processes, Anaerobic-aerobic bacterial process, Azo dyes, Biodegradation, Bioreactor, Decolorization, Integrated processes, Textile wastewater... 

Sequential biological—advanced oxidative— biological processes are proving to be promising in photodegradation of chlorophenols as model substrates, and promote total degradation [77]. 

Bioprocesses for the removal of nitrogen oxides from polluted air are an interesting alternative [58], but current reaction rates are still too low for large-scale applications. Advanced biological processes for the removal of NO from flue gases are based on the catalytic activity of either eukaryotes or prokaryotes, e.g. nitrification, denitrification, the use of microalgae and a combined physicochemical and biological process (BioDeNO ). 

Advanced oxidation processes (AOPs) are a range of water treatments which involve the in situ formation of radicals, particularly hydroxyl radicals, in sufficient quantity to affect chemical or biological contaminants. These include ultrasonic and ultraviolet irradiation but they are sometimes ineffective for the remediation of water which contains a mixture of organic and inorganic compounds. Chemical oxidants can be used to add additional oxidising power to such processes and ozone in conjunction with ultrasound is one such option [31]. 

There have also been significant advances in the imido chemistry of ruthenium and osmium. A variety of imido complexes in oxidation states +8 to +6 have been reported. Notably, osmium (VIII) imido complexes are active intermediates in osmium-catalyzed asymmetric aminohydroxyl-ations of alkenes. Ruthenium(VI) imido complexes with porphyrin ligands can effect stoichiometric and catalytic aziridination of alkenes. With chiral porphyrins, asymmetric aziridination of alkenes has also been achieved. Some of these imido species may also serve as models for biological processes. An imido species has been postulated as an intermediate in the nitrite reductase cycle. " ... 

Martin Jekel, Professor of Water Quality Control at the Technical University Berlin, has been involved in ozonation and oxidation research since 1976, especially concerning ozone/ biological activated carbon, microflocculation mechanisms of ozone and advanced oxidation processes for water and wastewaters. He studied chemistry, has a Ph.D. in chemical engineering and is a full professor since 1988. He contributed Chapter A 3 to this book. Technische Universitat Berlin, Institut fur Technischen Umweltschutz, Sekr. KF 4, Strasse des 17. Juni 135, D-10623 Berlin, Germany wrh itu201. ut.TU-Berlin.DE... 

This is another synthetic organic chemical classified as a priority pollutant of water and potential carcinogen for humans. The presence of a cyclic structure and oxygen in the carbon chain makes this compound very refractory to both aerobic and anaerobic biological oxidation. As a consequence, much research has been done on the treatment of this compound with advanced oxidation processes [174,188]. 

This entry introduces applications of ozone technology in various areas water and wastewater treatment control of the microbial safety of food decontamination of soils polymer surface modification and bleaching paper pulps. For water and wastewater treatment, in addition to being used alone, ozone is increasingly used in combination with heterogenous catalysts, UV/H2O2 (advanced oxidation process), and biological treatment to enhance ozonation efficiency. The discussion that follows mainly introduces the applications of ozone in water and wastewater treatment because ozone has been both extensively and intensively used in this area however, it does briefly describe other applications. 

Before considering the interest of UV spectrophotometry for the control of biological processes, a last physical treatment type must be presented. Advanced oxidation processes (AOP) are more and more used, because of their destruction power, preventing the pollution transfer (as it is the case for the other processes). AOP schemes include ozonisation, photo-oxidation and photo-catalysis processes, these last being based on the effect of UV radiation. 

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