Heterogeneous Fenton System

Costa, RCC Lelis, MFF Oliveira, LCA Fabris, JD Ardisson, JD Rios, RRVA Silva, CN Lago, RM. Novel active heterogeneous Fenton system based on Fe3-xMx04 (Fe, Co, Mn, Ni) The role of species on the reactivity towards H2O2 reactions. Journal of Hazardous Materials, 2006 129, 171-178. 

Moura, FCC Araujo, MH Costa, RCC Fabris, JD Ardisson, JD Macedo, WAA Lago, RM. Efficient use of Fe metal as an electron transfer agent in a heterogeneous Fenton system based on Fe°/Fc304 composites. 

H]-(m/z113) Scheme 3.29 A reaction view for phenol degradation by a heterogeneous Fenton system based on ESI-MS(/MS) data. 

Scheme 5.2 ESI-MS monitoring of phenol degradation through heterogeneous Fenton system [41].

Photo-initiated AOPs are subdivided into VUV and UV oxidation that are operated in a homogeneous phase, and in photocatalysis (Fig. 5-15). The latter can be conducted in a homogeneous aqueous phase (photo-enhanced Fenton reaction) or in a heterogeneous aqueous or gaseous phase (titanium dioxide and certain other metal oxide catalysts). These techniques apply UV-A lamps or solar UV/VIS radiation and they are in pre-pilot or pilot status. According to Mukhetjee and Ray (1999) the development of a viable and practical reactor system for water treatment with heterogeneous photocatalysis on industrial scales has not yet been successfully achieved. This is mainly related to difficulties with the efficient distribution of electromagnetic radiation (UV/VIS) to the phase of the nominal catalyst. 

Catalytic activity of composites B-N-Fe and Si-N-Fe when applying UV radiation in presence of hydrogen peroxide, oxalic acid, and EDTA is determined by formation of photo-Fenton, ferric-oxalate, and Fe-EDTA systems in the solution which leads to generation of the super-oxidant-hydroxyl radicals. At the same time, solutions practically are not polluted by iron. High catalytic activity of the composites is determined by combination of heterogeneous and homogeneous catalyses. 

Semiconductors excited by appropriate energy photons. Two weU-defined AOP s systems which have special interest, because natural solar light can be used, are heterogeneous photocatalysis with Ti02 and homogeneous photocatalysis by the photo-Fenton process. These processes are covered in detail in the following sections. 

Heterogeneous Ti02 photocatalysis and homogeneous photo-Fenton, are the AOPs for which the solar technologies have been most extensively studied and developed (13). In the last few years, solar photocatalysis processes have shown to be an important alternative for pesticide degradation in the field of AOPs (14, 15) with extended research performed at pilot-plant scale (16, 17). The renewed interest of researchers (18) in the photo-assisted Fenton processes (classic old reactive system, discovered by Fenton (19) in the last century) is today underlined by a significant number of studies devoted to wastewater treatment... 

Valizadeh, S., Rasouliferd, M.H., and Seyed Dorraji, M.S. (2014) Modified Fe304 hydroxyapatite nanocomposites as heterogeneous catalysts in three UV, vis and Fenton like degradation systems. Appl Surf. ScL, 319, 358-366. 

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