Fenton method

Oturan M A, J Peiroten, P Chartin, AJ Acher (2000) Complete destruction of p-nitrophenol in aqueous medium by electro-Fenton method. Environ Sci Technol 34 3474-3479. 

Dorathi PJ, Ranjit KP, Lee C-S (2008) Degradation of 2,4-dichlorophenol in aqueous solution by sono-Fenton method. Korean J Chem Engi 25(1) 112-117... 

Tarr, MA. Fenton and modified Fenton methods for pollutant degradation. 

Fenton and Modified Fenton Methods for Pollutant Degradation... 

Lignin, a major structural component of wood, was also degraded by a photo-Fenton technique [80]. Although this report demonstrated the ability of the method to degrade lignin, the study did not elaborate on potential applications in the pulp-and-paper industry. The treatment of kraft mill bleaching effluent by Fenton and photo-Fenton methods has been studied, and was reportedly more effective and more economical than several other techniques [81]. 

Maletzky P, Bauer R. Immobilisation of iron ions on Nation and its applicability to the photo-Fenton method. Chemosphere 1999 38 2315-2325. 

All these advanced methods have been compared with anodic oxidation for a 178-ppm 4-chlorophenol solution [140]. The mineralization rate was much faster for the new processes and the substrate was completely transformed into C02 by the Photoelectro-Fenton method, as can be deduced from data given in Fig. 22. In all cases, the initial intermediate was 4-chloro-l,2-dihydroxybenzene, which was further oxidized to yield maleic and fumaric acids with loss of Cl-. The subsequent degradation of these acids gave oxalic acid, which complexes with Fe(III). Such complexes are attacked slowly by OH, but decomposed quickly by UVA light. 

Oturan MA, Pinson J, Oturan N, Deprez D. Hydroxylation of aromatic drugs by the electro-Fenton method. Formation and identification of the metabolites of riluzole. New J Chem 1999 23 793-794. 

Chou S, Huang YH, Lee SN, Huang GH, Huang C. Treatment of high strength hexamine-containing wastewater by Electro-Fenton method. Water Res 1999 33 751-759. 

Huang YH, Chou S, Perng MG, Huang GH, Cheng SS. Case study on the bioeffluent of petrochemical wastewater by Electro-Fenton method. Water Sci Technol 1999 39 145-149. 

One of the most friendly, attractive and economically justified techniques used in homogeneous systems consists of the photo-Fenton method. The photo-Fenton reagent (Fe3+/Fe27H202) is an efficient and cheap reagent, which in a very simple way produces OH radicals for wastewater treatment, due to the fact that iron is a very abundant and non-toxic element and hydrogen peroxide is easy to handle and environmentally safe. Iron in its ferrous and ferric forms acts as a photocatalyst and requires a working pH <4. At higher pH values, iron precipitates as a hydroxide. The Fenton reaction, which usually operates at or near ambient temperature and pressure ... 

The degradation of aromatics, pesticides, herbicides, and other bio-recalcitrant compounds in industrial wastewaters can be efficiently achieved by means of the oxidative radicals generated in the Fenton and photo-assisted Fenton reaction [11], Among others, the photo-Fenton method has proved to be effective in the degradation of phenol and its halogenated derivatives [12-14], dioxins [15], nitroaniline [16],... 

The photo-Fenton method of wastewater treatment is developed in two main fields fitting of the usable radiation range to the solar light and immobilization of the photo-Fenton catalyst. 

Zhang, H., D. Zhang, and J. Zhou (2006). Removal of COD from landfiU leachate by electro-Fenton method. J. Hazard. Mater. 135,106-111. 

The photoelectro-Fenton method involves the simultaneous irradiation of the wastewater with UVA light while it is degraded by electro-Fenton in an undivided cell. UVA irradiation favors the regeneration of Fe2+ from additional photoreduction of Fe (OH)2+, which is the predominant Fe3+ species in acid medium (Sun... 

The electro-Fenton method (or EFR) was initially used for synthetic purposes considering the hydroxylation of aromatics in the cathodic compartment of a divided cell. Thus, the production of phenol from benzene (Tomat and Vecchi 1971 Tzedakis et al. 1989), (methyl)benzaldehydes and (methyl)benzyl alcohols from toluene or polymethylbenzenes (Tomat and Rigo 1976,1979,1984,1985) by adding Fe3+ to generate Fe2+ via reaction (19.13), as well as benzaldehyde and cresol isomers from toluene or acetophenone and ethylphenol isomers from ethylbenzene (Matsue et al. 1981) with direct addition of Fe2+, have been described. Further studies have reported the polyhydroxylation of salicylic acid (Oturan et al. 1992)... 

Song-hu, Y. and Xiao-hua, L. (2005) Comparison treatment of various chlorophenols by electro-Fenton method Relationship between chlorine content and degradation. J. Hazard. Mater. B118, 85-92. 

The photoelectro-Fenton method [98] complements the photo-Fenton and electro-Fenton reactions. In the latter, a potential is applied between two electrodes immersed in a solution containing Fenton reagent and the target compound. The recent study of the herbicide 2,4,5-T, performed in an undivided cell with a Pt anode and an 02-diffusion cathode, showed that the photo-electrochemical process was more powerful than the electro-Fenton process, which can yield only about 60-65% of decontamination. The electro-Fenton method provides complete destruction of all reaction intermediates, except oxalic acid, which, as already mentioned, forms stable complexes with Fe3+ that remain in the solution. The fast photodecarboxylation of such Fe(III)-oxalate complexes by UV fight explains the highest oxidative ability of the photoelectro-Fenton treatment, which allows a fast and total mineralization of highly concentrated acidic aqueous solutions of 2,4,5-T at low current and temperature. A similar behavior was found for the herbicide 3,6-dichloro-2-methoxybenzoic acid [99]. 

Fallmann H, Krutzler T, Bauer R, Maiato S, Blanco J (1999) Applicability of the Photo-Fenton Method for Treating Water Containing Pesticides, Catal. Today 54 309-319. 

Kin KT, Tang FIS, Chan SF, Raghavan S, Martinez S. Treatment of chemical-mechanical planarization wastes by electrocoagulation/electro-fenton method. IEEE Transactions on Semiconductor Manufacturing vol. 18, No. 2, May 2006. 

In most cases, photo assisted electrochemical degradation processes are used. For instance, in the aforementioned Fenton method, formation of complexes of iron ions with some intermediates such as oxalate ions can reduce the effectiveness of the process. Then, photoelectro-Fenton methods involve the use of UV irradiation to produce photolysis of such Fe complexes and increase the rate of Fe" regeneration by means of the photo-Fenton reaction ... 

Kin, K.T., Tang, H.S., Chan, S.F., Raghavan, S., 2006. Treatment of chemical—mechanical planarization wastes by electrocoagulation/electro-Fenton method. IEEE Trans. Semicond. Manuf. 19 (2006), 208-215. 

Electro-Fenton Methods Using Electrodes Modified with MN4 Compounds... 

In the Fenton method hydrogen peroxide reacts with Fe ions generating highly oxidizing hydroxyl and hydroperoxyl radicals, very effective for destroying organic... 

---