Ozone reactivity

Above pH 9, decomposition of ozone to the reactive intermediate, HO, determines the kinetics of ammonia oxidation. Catalysts, such as WO, Pt, Pd, Ir, and Rh, promote the oxidation of dilute aqueous solutions of ammonia at 25°C, only two of the three oxygen atoms of ozone can react, whereas at 75°C, all three atoms react (42). The oxidation of ammonia by ozone depends not only on the pH of the system but also on the presence of other oxidizable species (39,43,44). Because the ozonation rate of organic materials in wastewater is much faster than that of ammonia, oxidation of ammonia does not occur in the presence of ozone-reactive organics. 

Phenols. The first stable ozone oxidation product of phenol in water is ds ds-raucomc acid, which requires - 2 mol O /mol phenol. In practice, larger dosage levels of ozone are required because other ozone-reactive substances are present in most wastes. Ozone oxidation of phenoHc effluents is employed in paper mills, coke mills, oil refineries, and thermoplastic resin manufacture, producing effluents that are safe to freshwater biota (122,123) (see Lignin Pulp). 

Carter, W. P. L., "Development of Ozone Reactivity Scales for Volatile Organic Compounds," EPA 600/3-91-050. U.S, Environmental Protection Agency, August 1991. 

Overall DBP removal followed the order ozonation reactive GAC > UV irradiation>chlorination>bromination, with the magnetic treatment results being inconclusive. 

Reiss, R., P. B. Ryan, P. Koutrakis, and S. J. Tibbets, Ozone Reactive Chemistry on Interior Latex Paint, Environ. Sci. Technol., 29, 1906-1912 (1995b). 

TABLE 16.7 California s Low-Emission Vehicle Standards for Passenger Cars and Light-Duty Trucks Introduction of Ozone Reactivity Adjustment Factors"... 

Reiss, R., Ryan, P., Koutrakis, P. and Tibbetts, S. (1995a) Ozone reactive chemistry on interior latex paint. Environmental Science ej Technology, 29 (8), 1906-12. 

The alkylmercuric halides, on the other hand, reacted slowly enough with ozone to permit kinetic studies. While attempts were made to monitor ozone uptake during the first part of the reactions, it was clear that the primary and secondary alkylmercuric halides formed many ozone-reactive intermediates soon after the introduction of 03/02. Hence, in the case of isopropylmercuric chloride (Reaction 10, Table II), isopropyl alcohol was formed and had begun to react appreciably with ozone well before the mercurial had half reacted. By comparison, the reaction of tert-butylmercuric chloride was considerably faster than the primary and secondary alkylmercuric halides (Table III). In this case an excellent 1 1 correlation with ozone was noted throughout the majority of the reaction. Only at the end of this reaction, when other organic products began to appear (NMR), did the reaction mixture demand more than one equivalent of ozone. 

Sillman S., He D., Pippin M., Daum P., Kleinman L., Lee J.-H., and Weinstein-Lloyd J. (1998) Model correlations for ozone, reactive nitrogen, and peroxides for Nashville in comparison with measurements implications for VOC-NO, sensitivity. J. Geophys. Res. 103, 22629-22644. 

Langford, S.D., Bidani, A., Postlethwait, E.M. Ozone-reactive absorption by pulmonary epithelial lining fluid constituents. Toxicol Appl Pharmacol 732 (1995) 122-130. 

Nitrous oxide (N20), another greenhouse gas, is stable in the troposphere, but oxidizes to ozone-reactive NO in the stratosphere. Molecule for molecule, N20 is currently about 200 times more effective in absorbing long-wave infrared radiation than is carbon dioxide, and its atmospheric concentration... 

Andersson-Skold Y, Grennfelt P, Pleijel K (1992) Photochemical ozone creation potentials a study of different concepts. J Air Waste Manage Assoc 42(9) 1152-1158 Carter WPL (1994) Developmoit of ozone reactivity scales for volatile organic compoimds. J Air Waste Manage Assoc 44 881-899... 

The future research directions for the UCR EPA chamber will of course depend on funding availability and the interests of the funding agencies, but we would expect the research would be designed to take full advantage of its capabilities. In any case, we expect to continue the ozone reactivity and gas-phase mechanism studies that are currently underway, with the mechanism evaluation being focused on aromatics, whose mechanism are the most... 

The two large open circles on Figure 1 show the ROG and NOx levels chosen to serve as the base case in the incremental reactivity experiments that are currently underway in this chamber to assess ozone impacts of various different types of VOCs (Carter, 2004c). The 25-30 ppb NOx levels were chosen to be representative of pollution episodes of interest in California, based on input provided by the staff of the California Air Resources Board, which is funding most of the current reactivity studies. The ROG/NOx ratios were chosen to represent two sets of conditions of NOx availability relevant to VOC reactivity. The lower ROG/NOx ratio was chosen to represent the relatively higher NOx conditions of maximum incremental reactivity (MIR) where ozone is most sensitive to VOCs, to approximate the conditions used to derive the widely-used MIR ozone reactivity scale (Carter, 1994). The higher ROG/NOx ratio was chosen to be one-half that yielding maximum ozone levels, and is used to represent conditions where ozone is NOx-limited, but not so NOx-limited that VOC reactivity is irrelevant. These are referred to in the subsequent discussion as the MIR and MOIR/2 base eases, respeetively. 

Carter, W. P. L. Development of ozone reactivity scales for volatile organic compounds, J. Air Waste Manage. Assoc., 44, 881-899. (1994)... 

Development of Ozone Reactivity Scales for Volatile Organic Compounds... 

The last general category—namely, the reaction of ozone with aromatic hydrocarbons, has received an enormous amount of attention by ozone chemists. Most of this attention has concerned rate and reactivity studies in an attempt to correlate these experimental quantities with some known parameters of the hydrocarbons. Several reactivity correlations have been proposed, including those with bond localization energy, atom localization energies, and oxidation-reduction potentials. This category is also represented by a paper in this section, in which a possible correlation between ozone reactivity and carcinogenicity of some polycyclic aromatic compounds is explored. 

Modification of Ozone Reactivity. The reactivity of ozone toward various unsaturated moieties can be moderated by the addition of either Lewis acids or pyridine to the ozonations. Enhanced electrophilic ozone reactivity toward aromatic substrates is observed when the Lewis acids Aluminum Chloride or Boron Triftuoride are added to reaction mixtures. Conversely, an apparent decrease in ozone reactivity and a concurrent increase in the regioselectivity of ozone attack can be achieved by adding small amounts of pyridine to ozonolyses (eq 26). It is thought that coordination of either the Lewis acid or basic pyridine to ozone results in the modified reactivity. 

Oxygen-deficient atmosphere—An atmosphere with oxygen content below 19.5% by volume. Ozone—Reactive oxidant that contains three atoms of oxygen. 

Ozone Reactive toxic chemical gas consisting of three oxygen atoms, a product of the photochemical process involving the Sun s energy and ozone precursors, such as hydrocarbons and oxides of nitrogen. Ozone in the troposphere causes numerous adverse health effects and is a major component of smog. 

Type Name CAS VOC in US HAP in US VOC in Europe Ozone Reactivity MIR Exposure Limit in US... 

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