H2O2 process

This process is similar to the Bayer process except that hydrogen peroxide is used as the oxidizing agent and the ketone used is methyl ethyl ketone  

Since the reaction with hydrogen peroxide is too slow, an activator is added as a catalyst, which in the process variant published by ATOCHEM is a mixture of acetamide, ammo- 

The methyl ethyl ketone azine formed, which is poorly soluble in water, is separated and hydrolyzed to hydrazine and ketone. The cataly.st-containing aqueous solution is returned to the synthesis. 

This process is operated commercially by ATOCHEM in France and in a very similar process by Mitsubishi Gas Chemicals in Japan. The advantage of this proce.ss over the Bayer and Raschig proces.ses is that sodium chloride is not formed as a byproduct. 

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The final effluent from the H2O2 process is basically clean whereas the chlorine based oxidants impart high chloride levels to the stream. 

Kim I, Yamashita N, Tanaka H (2009) Performance of UV and UV/H2O2 processes for the removal of pharmaceuticals detected in secondary effluent of a sewage treatment plant in Japan. J Hazard Mater 166 1134-1140... 

Ozone is main component in many oxidation processes assembled imder the term ozonation processes. In these processes ozone is applied either alone (O3 process) or with the addition of oxidant, e.g. H2O2 (O3/H2O2 process), UV radiation (explained in above subchapter), catalyst, activated carbon, ultrasoimd etc. Ozone is inorganic molecule constituted by three atoms of oxygen. It is present in nature in upper atmosphere in the form of stratospheric layer aroimd the earth, and it is formed by the photolysis of diatomic oxygen and further recombination of atomic and diatomic oxygen, shown by equations (25) and (26) [35] ... 

Figure 14. Influence of the initial H2O2 concentration (A), and initial pH value (B) on the decolorization and mineralization efficiency, and final pH values after a one-hour treatment by UV/O3/H2O2 process.

Figure 15. RB137 (20 mgL ) decolorization and mineralization efficiency as well as changes of pH values during the treatment (A), and influence of NH4ZSM5 and HY zeolites on RBI37 degradation efficiency (B) by UV/O3/H2O2 process (pH 7 and c(H2O2)=1.0 mM).

Complete bleaching with non-zeolite case was achieved after 20 minutes of treatment, trend of the curve which connects points of measured TOC removals is almost linear, zeolite addition caused delay in decolorization of RB137, while NH4ZSM5 zeolite addition showed positive effect to TOC removal after 30. minute of process. But it should be pointed out that final achieved mineralization, 69.3 % TOC removal, by UV/O3/H2O2 process is somewhat higher than that obtained by UV/O3 process, 64.4 % TOC removal. 

Kusic, H Koprivanac, N Loncaric Bozic, A Papic, S Petemel, I Vujevic, D. Reactive dye degradation by a photochemical AOP - development of a kinetic model for UV/H2O2 process. Chemical and Biochemical Engineering Quarterly, 2006 in press. 

Tuhkanen, T. UV/H2O2 process. In Parsons SA, editor. Advanced oxidation processes for water and wastewater treatment. London IWA Publishing 2004 86-110. 

Muruganandham, M Swaminathan M. Photochemical oxidation of reactive azo dye with UV-H2O2 process. Dyes and Pigments, 2004 62,169-115. 

Figure 5.17. TEM image of (a) fresh Pd/alumina catalyst and (b) used catalyst in the H2O2 process, showing sintered twinned particles.

Sorensen M, Frimmel FH. Photochemical degradation of hydrophilic xenobiotics in the UV/H2O2 process influence of nitrate on the degradation rate of EDTA, 2-amino-1-naphthalenesulfonate, diphenyl-4-sulfonate and 4,4 -diaminostilbene-2,2 -disulfonate. Water Res 1997 31 2885-2891. 

Recently, the degradation kinetics of two pharmaceutical intermediates [5-methyl-l,3,4-thiadiazole-2-methylthio (MMTD-Me) and 5-methyl-1,3,4-thiadiazole-2-thiol (MMTD)] has been studied in order to assess the effectiveness and the feasibility of UV processes. For both substrates, the results showed that no degradation occurred when H2O2 was used alone and that UV and UV/H2O2 processes were both effective for degrading the substrates, but... 

Stefan MI, Bolton JR (1999) Reinvestigation of the Acetone Degradation Mechanism in Dilute Aqueous Solution by the UV/H2O2 Process, Environ. Sci. Technol. 33, No. 6 870-873. 

WoLFRUM EJ, Ollis DE, Lim PK, Eox MA (1994) The UV-H2O2 Process Quantitative EPR Determination of Radical Concentrations, J. Photochem. Photohiol. A Chem. 78 259-265. 

Sorensen M, Frimmel F (1997) Photochemical Degradation of Hydrophilic Xenobiotics in the UV/H2O2 Process Influence of Nitrate on the Degradation Rate of EDTA, 2-Amino-l-naphthalenesulfonate, Diphenyl-4-sulfonate and 4,4 -Diaminostilbene-2,2 -disulfonate, Wat. Res. 31 2885-2891. 

Table 13.5 Polimeri Europa TS-I/H2O2 process material balance.

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