Advanced Oxidation Processes for Wastewater Treatments

Early transition metals (V, Nb, Ta, Mo, W) in their highest oxidation states, can form metal-oxygen cluster anions, commonly named polyoxoanions or polyoxometalates (POMs). POMs have been largely used as efficient photocatalyst for the complete degradation of organic pollutants in water (Antonaraki et al., 2002 Kormali et al., 2004 Mylonas and Constantinou, 1996). These compounds have interesting redox properties for catalytic applications. In particular, POMs in the solid state are particularly suitable 

The heterogenization of a lipophilic salt of deeatungstate, ( Bu4N)4Wio032 (not soluble in water), in PVDF membranes (PVDF-Wio), prepared by phase inversion technique induced by a nonsolvent (Kimmerle and Strathmann, 1990), at different catalyst loading (14.3, 25.0, and 33.3 wt% with respect to polymer mass) was investigated (Bonchio et al., 2003 Fontananova et al., 2006b). 

Solid-state characterization techniques have been used to verify that the heterogenization procedure did not damage the catalyst. Fourier transform-infrared (FT-IR) spectra give useful indication about the structure of the catalyst heterogenized in the membrane. FT-IR spectra confirmed that the catalyst stmetore is preserved within the polymeric membrane (Fig. 27.1). The infrared spectrum of the catalytic membranes show the characteristic bands of Wio units (595, 803, 895, 958 cm ), as well as those typical of the employed alkylam-monium cation (2870 cm ). 

Also spectroscopic properties of the catalyst heterogenized in PVDF membranes are preserved as confirmed by the presence of the CT band at 324 nm in the DR-UV spectra of the catalytic membranes (Fig. 27.2). Moreover, it is important to note that the PVDF membrane prepared without the catalyst (PVDF reference) does not show any absorption in the region of interest for the catalyst. 

The catalytic membranes were successfully applied in the aerobic photooxidation of phenol, one of the main organic pollutants in wastewater, providing stable and recyclable photoeatalytic systems. The catalytic tests were carried out in a photoeatalytic membrane reactor operating with flow-through at different transmembrane pressures (TMP). 

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Ruppert G, Bauer R, Heisler G (1994) UV-O3, UV-H2O2, UV-Ti02 and the Photo-Fenton Reaction- Comparison of Advanced Oxidation Processes for Wastewater Treatment, Chemosphere 28, No. 8 1447-1454. 

Munoz Ortiz, I. (2006) Life cycle assessment as a tool for green chemistry application to different advanced oxidation processes for wastewater treatment,... 

Ruppert G. and Rupert. B., UV-O3, UV-H2O2, UV-TiOi and the photo-fenton reaction comparison of advanced oxidation processes for wastewater treatment . 

Comninellis, Ch. and Pulgarin, C. (1993) Electrochemical oxidation of phenol for wastewater treatment using Sn02 anodes. I. Appl. Electrochem. 23, 108-112 Faouzi, M., Cafiizares, R, Gadri, A., Lobato, I., Nasr, B., Paz, R., Rodrigo, M.A. and Saez, C. (2006) Advanced oxidation processes for the treatment of wastes polluted with azoic dyes. Electrochim. Acta 52, 325-331... 

Sirds, I., Arias, C., Cabot, P. L., Centellas, F., Rodriguez, R. M., Garrido, J. A. and Brillas, E. (2004) Paracetamol mineralization by advanced electrochemical oxidation processes for wastewater treatment. Environ. Chem. 1,26-28. 

Parsons, S. (2004) Advanced Oxidation Processes for Water and Wastewater Treatment, IWA Publishing, London. 

Parsons, SA Williams, M. Introduction. In Parsons SA, editor. Advanced oxidation processes for water and wastewater treatment. London IWA Publishing 2004 1-6. 

Bigot V, Luck F, Paillard H, Wagner A (1994) Evaluation of advanced oxidation processes for landfill leachate treatment, in Proceedings of the international ozone symposium Application of ozone in water and wastewater treatment , Bln A K (ed.) Warsaw Poland May 26-27 330-343. 

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. 

Kalra, S.S., Mohan, S., Sinha, A., Singh, G., 2011. Advance oxidation processes for treatment of textile and dye wastewater a review. In 2nd International Conference on Environmental Science and Development, IPCBEE, 4, 271-275. 

OLLER I, MALATO s et al. (2011) Combination of Advanced Oxidation Processes and biological treatments for wastewater decontamination - A review. Science of The Total Environment 409(20) 4141-4166. 

Parsons S (2004) Advanced oxidation process for water and wastewater treatment IWA publishing, Lxtndon... 

Zaviska, R, Drogui, R, Mercier, G., et al. (2009). Advanced Oxidation Processes for Waters and Wastewaters Treatment Application to Degradation of Refractory Pollutants, Revue des Sciences de I Eau, 22, pp. 535-564. 

The advanced oxidation processes offer the possibility for destruction of recalcitrant biodegradable and toxic organic pollutants. The field of applications regarding wastewater treatment varies. AOPs can be applied as ... 

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