Ozone and hydrogen peroxide

Aldehydes are easily oxidized to carboxylic acids under conditions of ozonide hydroly SIS When one wishes to isolate the aldehyde itself a reducing agent such as zinc is included during the hydrolysis step Zinc reduces the ozonide and reacts with any oxi dants present (excess ozone and hydrogen peroxide) to prevent them from oxidizing any aldehyde formed An alternative more modem technique follows ozone treatment of the alkene m methanol with reduction by dimethyl sulfide (CH3SCH3)... 

Combination of ozone and hydrogen peroxide (such as in the HiPOx system). 

EnZone [Enzyme ozone] A pulp bleaching process using the enzyme xylanase in combination with oxygen, ozone, and hydrogen peroxide. Invented by K.-E. L. Eriksson at the University of Georgia and piloted in 1998. 

AOPs are less appropriate for the complete treatment of wastewater streams containing high concentration of organic pollutants. The main reason is that the energy costs and costs of chemicals such as ozone and hydrogen peroxide are relatively high. In case of UV also the equipment costs may be substantially. To treat these concentrated waste streams the application of AOPs has to be focused on the selective oxidation of specific toxic pollutants or on the partial oxidation of pollutants. 

Adverse oxidation of membrane occurs at higher concentrations of oxidizers such as chlorine, ozone and hydrogen peroxide. The chemicals are important for slime control, and rather high concentrations of the chemicals are dosed for sterilization of RO feed system, especially in cases of ultrapure water system, and of waste water treatment system. The evaluation of membrane durability against oxidizing chemicals informs us the proper procedures for RO maintenance. 

Glaze, W Kang, J. Advanced oxidation processes. Test of a kinetic model for the oxidation of organic compounds with ozone and hydrogen peroxide in a semi batch reactor, Industrial and Engineering Chemistry Research, 1989 28, 1580-1587. 

Physicochemical treatment of pharmaceutical wastewater includes screening, equalization, neutralization/pH adjustment, coagulation/flocculation, sedimentation, adsorption, and ozone and hydrogen peroxide treatment. Detailed descriptions of the various physicochemical treatment processes are described in the following sections. 

Oxidation processes do not work well in the presence of free-radical scavengers that consume the ozone and hydrogen peroxide and inhibit the effect of the UV radiation. The presence of such scavengers requires higher doses of oxidizers and larger UV fluxes. 

The Carson Enviroimental (CE) technology is a mobile, ex sitn technology for remediating particnlate media or sohd materials. The technology combines gas-phase oxidation agents or chemicals (ozone and hydrogen peroxide) and ultraviolet (UV) hght in an on-site decontamination unit. 

Penkett, S. A., B. M. R. Jones, K. A. Brice, and A. E. J. Eggleton, The Importance of Atmospheric Ozone and Hydrogen Peroxide in Oxidizing Sulphur Dioxide in Cloud and Rain Water, Atmos. Environ., 13, 123-137 (1979). 

The numerator contains all hydroxyl radical forming reactions and all initiating reactions are summarized (Sk c(/()). The denominator contains all hydroxyl radical consuming reactions. The second term includes all reactions with intermediates (EkPi c(P,)), the third the reactions with scavengers(Lksi c(S,)). Similarly, the steady-state concentrations of ozone and hydrogen peroxide can be calculated from the liquid phase mass balances. 

Using this approach of a selectivity term SPFR Sunder and Hempel (1996) successfully modeled the oxidation of small concentrations of Tri- and Perchloroethylene (c(M)a = 300-1300 pg D) by ozone and hydrogen peroxide in a synthetic ground water (pH = 7.5-8.5 c(Sj) = 1-3 mmol C03 L"1). In this study an innovative reaction system was used the oxidation was performed in a tube reactor and mass transfer of gaseous ozone to pure water was realized in a separate contactor being located in front of the tube reactor. By this way a homogeneous system was achieved. Since the two model compounds react very slowly with molecular ozone (kD < 0.1 L mol-1 s "1), nearly the complete oxidation was due to the action of hydroxyl radicals, which were produced from the two oxidants (03/H202). With... 

Glaze W H, Kang J-W (1989 a) Advanced Oxidation Processes. Description of a kinetic Model for the Oxidation of hazardous Materials in Aqueous Media with Ozone and Hydrogen Peroxide in a semibatch Reactor, Industrial Engineering Chemical Research 28 1573-1580. 

Waters, J.W., J.C. Hardy, R.F. Jamot and H.M. Pickett (1981) Chlorine monoxide radical, ozone and hydrogen peroxide by microwave limb sounding. Science 214 61-64. 

Quantum Yield of Ozone and Hydrogen Peroxide Decomposition at 2537 A. 

The reaction of ozone and hydrogen peroxide in its ionic form and photolysis of both oxidants constitute the initiation reactions leading to a mechanism of hydroxyl radical formation in water. This mechanism is basically the same for all these advanced oxidation systems, whereas the main differences lie in the initiating steps. These oxidation technologies have been applied for the treatment of pollutants in water for more than two decades. 

The treatment of s-triazine herbicides constitutes a clear application of the combined use of ozone and hydrogen peroxide. At the end of the eighties, this system was investigated to remove triazines in several pilot plants in France and the United Kingdom [228], The successful results obtained led to the implementation of this system in some water-treatment plants, such as those owned by the Compagnie Generale des Eaux in Paris [228], Since then, the 03/H202system has been used in many waterworks to improve the removal of. v-triazines. It should be noted, however, that ozone processes may not be appropriate for the removal of herbicides from water because of the potential formation of very low concentrations of harmful intermediates. 

Sunder M, Hempel DC. Oxidation of tri- and perchloroethene in aqueous solution with ozone and hydrogen peroxide in a tube reactor. Water Res 1997 31 33 40. 

On the other hand, if the oxygen is very dry3 the oxidation proceeds exceedingly slowly, and probably if the system were entirely free from water no action would take place at all. Ozone and hydrogen peroxide, which are produced during the oxidation of moist phosphorus,4 do not occur m the dry reactions. The slow oxidation of phosphorus in various oils has also been studied.5... 

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