Ozonization of organic compounds

It is evident that for ordinary preparative work the careful calibration given in section G is not essential. It is only necessary to adjust the voltage of the transformer to about 10,000 to 11,000 volts and turn on the flow of oxygen to as rapid a rate as the absorption tubes will handle when surrounded by cooling baths. The amount of ozone produced in 5 minutes at the observed flowmeter reading is determined as in section F. By operating the ozonizer at this rate of flow and voltage the ozonization of organic compounds can be carried out.  [c.75]

The rate of aqueous ozonation reactions is affected by various factors such as the pH, temperature, and concentration of ozone, substrate, and radical scavengers. Kinetic measurements have been carried out in dilute aqueous solution on a large number of organic compounds from different classes (56,57). Some of the chemistry discussed in the foUowing sections occurs more readily at high ozone and high substrate concentrations.  [c.493]

More precisely, the rate of ozone formation depends closely on the chemical nature of the hydrocarbons present in the atmosphere. A reactivity scale has been proposed by Lowi and Carter (1990) and is largely utilized today in ozone prediction models. Thus the values indicated in Table 5.26 express the potential ozone formation as O3 formed per gram of organic material initially present. The most reactive compounds are light olefins, cycloparaffins, substituted aromatic hydrocarbons notably the xylenes, formaldehyde and acetaldehyde. Inversely, normal or substituted paraffins.  [c.261]

Addition compounds called ozonides are produced when alkenes react with ozone and reductive cleavage of these compounds is used extensively in preparative and diagnostic organic chemistry.  [c.264]

Kinetics and Mechanism of Ozone Reactions. Ozone attacks nucleophilic centers, ie, points of high electron density, in organic substrates. Reactivity of potential reaction sites is enhanced by the presence of electron-donating groups such as CH, and decreased by electron-withdrawing groups such as C=0, COOH, Cl, and NO2. Reaction products depend on solvent type (reactive or nonreactive) and ozonation conditions. Ozone does not totaHy mineralize, ie, convert to CO2 and water, most organic compounds during water treatment. Except in rare cases, such as the oxidation of formate, only partial oxidation is achieved on account of the low reactivity of common intermediate oxidation products, eg, acetic and oxaHc acids. Although ozone has a high thermodynamic oxidation potential, its effectiveness in water treatment depends on the kinetics of its reactions, which can vary widely indeed, rate constants can vary over 14 orders of magnitude, from for acetic acid to 10 L/(mol-s) for phenolate ion (56).  [c.493]

Below pH 7 and normal temperature, ozone reacts selectively, ie, direcdy, with organic compounds. However, at pH > 7, natural waters, ozone also can react nonselectively or indirectly through HO radicals formed by the hydroxyl ion-catalyzed decomposition of ozone. Hydroxyl radicals are nonselective oxidants that react rapidly, by radical addition, hydrogen abstraction, and electron transfer, with functional groups (eg, alkyl) that normally are resistant to ozone. Rate constants generaHy vary over the narrow range of 10 —10 L/(mol-s). However, the avaHabHity of hydroxyl radicals for oxidation of organics is decreased by radical scavengers such as bicarbonate and carbonate ions.  [c.493]

Disinfection. Ozone is a more effective broad-spectmm disinfectant than chlorine-based compounds (105). Ozone is very effective against bacteria because even concentrations as low as 0.01 ppm are toxic to bacteria. Whereas disinfection of bacteria by chlorine involves the diffusion of HOGl through the ceU membrane, disinfection by ozone occurs with the lysing (ie, mpture) of the ceU wall. The disinfection rate depends on the type of organism and is affected by ozone concentration, temperature (106), pH, turbidity, clumping of organisms, oxidizable substances, and the type of contactor employed (107). The presence of oxidizable substances in ordinary water can retard disinfection until the initial ozone demand is satisfied, at which point rapid disinfection is observed.  [c.501]

Degradation of Readily Oxidizable Organics. Organic contaminants in water supphes consist of not only natural organic matter from various sources but also synthetic organic chemicals. More than 700 organic compounds have been identified in drinking water. Not all of these materials are oxidized by ozone at the same rate some halogenated hydrocarbons are not oxidized at all. Materials that are oxidized readily by ozone include certain phenohcs, detergents, pesticides, herbicides (qv), chemical-manufacturing wastes, humic acids, aromatic compounds, proteins, and most amino acids.  [c.502]

Under Section 183 of the Clean Air Act Amendments of 1990, the Environmental Protection Agency is required to study volatile organic compound (VOC) emissions from consumer and commercial products. The goal is to (/) determine the potential of the VOCs to contribute to ambient ozone levels (2) estabhsh criteria for regulating consumer and commercial products and (J) submit a report of this study to the U.S. Congress (65). As of this writing, this report has not been submitted. Although it remains unclear what the exact nature of regulation will be, VOC reductions in poHsh formulations are underway. The State of California Air Resource Board has imposed limits on the content of volatile organic compounds in products sold in its jurisdiction (66). Much of the work described herein pertains to reductions in VOC content in poHsh formulations.  [c.211]

Of the NAAQS standards, ozone nonattainment has the greatest impact on solvent operations. Although solvent operations do not emit ozone directly, solvents, as volatile organic compounds (VOCs), react with nitrogen oxides in the atmosphere under the influence of sunlight to produce photochemical smog, of which ozone is a significant component. Implementation plans reduce ozone levels by reducing VOC emissions from all sources. As VOC emitters, solvent-using operations are also regulated to attain ozone compliance. Lower emissions are usually attained by either lowering solvent usage in the product or operation, capturing and/or destroying the solvent by various means, or adopting a nonsolvent or reduced solvent technology.  [c.262]

Ozone can be used to completely oxidize low concentrations of organics in aqueous streams or partially degrade compounds that are refractory or difficult to treat by other methods. Compounds that can be treated with ozone include alkanes, alcohols, ketones, aldehydes, phenols, benzene and its derivatives, and cyanide. Ozone readHy oxidizes cyanide to cyanate, however, further oxidation of the cyanate by ozone proceeds rather slowly and may require other oxidation treatment like alkaline chlorination to complete the degradation process.  [c.163]

Ozonation can be enhanced by the addition of ultraviolet (uv) radiation. This combination can be effective in degrading chlorinated organic compounds and pesticides. In addition, metal ions such as iron, nickel, chromium, and titanium [7440-32-6] can act as catalysts, as can ultrasonic mixing.  [c.163]

Disinfection By-Products. Disinfection by-products with chlorine and bromine sanitizers include chlorate and nitrate ions, inorganic and organic halamines and halogenated organic compounds (primarily trihalomethanes, THMs). Use of ozone can lead to additional by-products, eg, bromate ion and various organic compounds (see Ozone). The average concentration of NO3 found in Miami, Florida, pools is well below the drinking water standard of 45 ppm (72). The primary source of chlorate is beheved to be an impurity in hypochlorite sanitizers, especially sodium hypochlorite. No drinking water standard for chlorate has been issued.  [c.304]

Volatile Organic Compounds. As coatings dry, solvents ate released into the atmosphere, where they undergo chemical reactions in sunlight and produce photochemical smog and other air poUutants (see Air pollution). As a general rule, the volatile organic compound (V OC) content of marine coatings is restricted to 340 g/L. In the locations where ozone (qv) levels do not conform to the levels estabHshed by the Environmental Protection Agency, regulations requite an inventory of all coatings and thinners from the time they ate purchased until they ate used.  [c.363]

Ozone 40 of volatile organic compounds  [c.2157]

Prepai ative isolation of nonvolatile and semivolatile organic compounds fractions (hydrophobic weak acids, hydrophobic weak bases, hydrophobic neutrals, humic and fulvic acids) from natural and drinking waters in optimal conditions was systematically investigated by solid-phase extraction method with porous polymer sorbents followed by isolation from general concentrate of antropogenic and/or toxic semivolatile compounds produced in chlorination and ozonation processes.  [c.413]

The general procedure consists in dissolving a weighed amount of the compound in a suitable solvent such as glacial acetic acid, methyl chloride, ethyl chloride, or carbon tetrachloride. The solution is placed in tube H and such an amount is used that the same hydrostatic head is obtained as when the 5% potassium iodide solution was used in both tubes H and J. Usually both tubes H and I are surrounded by cooling baths. The ozonizer is started and the gases by-passed through the destroyer for about 5 minutes while the apparatus is attaining equilibrium. The ozonized oxygen is then passed through the solution of the compound for the calculated time. Since all organic compounds do not absorb ozone rapidly enough for a quantitative absorption it is frequently necessary to run the ozonization longer. The presence of unsaturation may often be detected by testing a small portion of the reaction mixture with a dilute solution of bromine in carbon tetrachloride. The ozonization is continued until the test with the bromine solution is negative.  [c.71]

At higher secondary voltages the percentage of nitrogen pentoxide rises. A decrease in the rate of flow also increases the amount of nitrogen pentoxide. It is obvious from the data in Table III that the amounts of nitrogen pentoxide are very small and need to be considered only when examining a reaction mixture for small amounts of by-products or when the presence of this oxide of nitrogen would act as a catalyst for the oxidation of the organic compounds by oxygen or ozone.  [c.73]

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.  [c.177]

Ozone (O3) is a colorless, reactive oxidant gas that is a major constituent of atmospheric smog. Ground-level ozone is formed in the air by the photochemical reaction of sunlight and nitrogen oxides (NO,), facilitated by a variety of volatile organic compounds (VOCs), which are photochemically reactive hydrocarbons. The relative importance of the various VOCs in the oxidation process depends on their chemical structure and reactivity. Ozone may be formed by the reaction of NO, and VOCs under the influence of sunlight hundreds of kilometers from the source of emissions. Ozone concentrations are influenced by the intensity of solar radiation, the absolute concentrations of NO, and VOCs, and the ratio of NO, to VOCs. Diurnal and seasonal variations occur in response to changes in sunlight. In addition, ground-level ozone accumulation occurs when sea breezes cause circulation of air over an area or when temperature-induced air inversions trap the compounds that produce smog. Peak ground-level ozone concentrations are measured in the afternoon. Mean concentrations are generally highest during the summer. Peak concentrations of ground-level ozone rarely last longer than two to three hours. Registered average natural background concentrations of ground-level ozone are around 30 to 100 ftg/m Short-term (one-hour) mean ambient concentrations in urban areas may exceed 300 to 800 ftg/m Both natural and  [c.29]

Equipment sources can be of two types namely, HVAC system and non-HVAC system equipment. In an HVAC system, the sources of contamination may be dust or dirt in ductwork or other components, microbiological growth in drip pans, humidifiers, ductwork, coils, improper use of biocides, sealants, and/or cleaning compounds, improper venting of combustion products, refrigerant leakage. From non-HVAC equipment, the emissions can be from office equipment (volatile organic compounds, ozone), supplies (solvents, toners, ammonia), emissions from shops, labs, cleaning processes, elevator motors, and other mechanical systems.  [c.189]

UAM-IV (Urban Airshed Model)-. UAM-IV is an urban scale, three dimensional, grid type numerical simulation model. The model incorporates a condensed photochemical kinetics mechanism for urban atmospheres. UAM-IV is designed for computing ozone (O3) concentrations under shortterm, episodic conditions lasting one or two days resulting from emissions of oxides of nitrogen (NOJ, volatile organic compounds (VOC), and carbon monoxide (CO). The model treats VOC emissions as their carbon-bond surrogates. Click the following filename to download the file  [c.332]

Ozone (Oj) a gas similar to oxygen that is a criteria air pollutant and a major constituent of smog. See also reactive organic compounds volatile organic compounds.  [c.541]

Volatile Organic Compounds (VOC) organic compounds that vaporize readily and contribute to the development of ozone. Many VOCs are also hazardous air pollutants. See also reactive organic compounds.  [c.552]

Other treatment technologies that have potential for full-scale adoption are photochemical oxidation using ozone and UV radiation or hydrogen peroxide for destruction of refractory organic compounds. One example of a technology that was developed outside North America and later emerged in the U.S. is the Haberer process. This process combines contact flocculation, filtration, and powdered activated carbon adsorption to meet a wide range of requirements for surface water and groundwater purification.  [c.10]

The most significant environmental and health issues affecting the paint and coatings industry in the 1990s are regulations to lower the VOC content for virtually all types of paints and to restrict the use of certain solvents known as hazardous air pollutants (HAPs) under the federal Clean Air Act. Except for the water in a latex paint or in other water-based coatings, solvents used in house paints are mosdy all VOCs. Several states, along with the U.S. EPA, have implemented environmental regulations to restrict the VOC content of paints, as mandated by the Clean Air Act. These regulations are aimed at minimizing the emission of organic compounds from paints that contribute to the formation of air pollution in the form of smog or ground-level ozone.  [c.547]

H. Ozonizalion of organic compounds. The ozonization of each unsaturated organic compound is more or less an individual problem, but some general comments may be made. Organic ozonides are highly explosive, and hence it is safest to carry out the ozonization in a solvent which dissolves both the original compound and the ozonide. In all cases, a shatterproof screen of laminated safety glass should be placed between the operator and the tubes H, I, and J. A second screen should be placed back of the tubes to protect other pieces of the apparatus.  [c.71]

Although it was known for some time that ozone cracks rubber products under tension, the problem was not related to air pollution. During the early 1940s, it was discovered that rubber tires stored in warehouses in Los Angeles, California, developed serious cracks. Intensified research soon identified the causative agent as ozone that resulted from atmospheric reaction between sunlight (3000-4600 A), oxides of nitrogen, and specific types of organic compounds, i.e., photochemical air pollution.  [c.133]

EKMA was developed for relating concentrations of photochemically formed ozone to levels of organic compounds tmd oxides of nitrogen.  [c.384]

Chemical Reaction. Reaction of gaseous pollutants can open up new pathways for recovery. Utilization of alkaline scmbbing solutions to collect acidic gases has been discussed. Nitrogen oxides can be decomposed to N2 and O2 by reaction with H2 or CH. Many odors can be controlled by scmbbing organic compounds with solutions of strong oxidants such as potassium permanganate [7722-64-7] KMnO nitric acid [7697-37-2] HNO hydrogen peroxide [7722-84-17, H2O2 hypochlorites and ozone, O. Gas—soHd reactions such as the introduction of hydrated lime into a S02-containing due gas stream (56) are also feasible although these schemes usually fall significantly short of 100% pollutant removal. Dry injection of soHd sodium bicarbonate [144-55-8] NaHCO, has been studied for removal of both SO and NO from due gas, for HCl removal from waste incineration emission (57), and for other hazardous gases from hazardous waste incineration (58). Flue gas humidification generally aids in achieving a more complete gas-soHd reaction. A volatile vapor pollutant can be rendered significantly less volatile by increasing its molecular weight, such as by vapor phase chlorination. An example of a gaseous pollutant control problem that can be changed to a particulate one is the reaction of gaseous HCl with ammonia to produce NH Cl smoke.  [c.389]

Odor Control Methods. Absorption, adsorption, and iaciaeration are all typical control methods for gaseous odors odorous particulates are controlled by the usual particulate control methods. However, carrier gas, odorized by particulates, may require gaseous odor control treatment even after the particulates have been removed. For oxidizable odors, treatment with oxidants such as hydrogen peroxide (qv), ozone (qv), and KMnO may sometimes be practiced catalytic oxidation has also been employed (see Exhaust control, industrial). Odor control as used ia rendering plants (327), spent grain dryers (328), pharmaceutical plants (329—331), and cellulose pulpiag (332) has been reviewed (333—335) some reviews are presented ia two symposium volumes (336,337) from APCA Specialty Conferences. The odor-control performances of activated carbon and permanganate—alumina for reduciag odor level of air streams containing olefins, esters, aldehydes, ketones, amines, sulfide, mercaptan, vapor from decomposed cmstacean shells, and stale tobacco smoke have been compared (338). Activated carbon produced faster deodorization ia all cases. Activated carbon adsorbers have been used to concentrate odors and organic compounds from emission streams, producing fuels suitable for iaciaeration (339). Both air pollution control and energy recovery were accompHshed.  [c.412]

Manganese dioxide, in combination with other metal oxides, forms a series of active catalysts (60) that participate in a variety of environmentally important oxidation and decomposition reactions. The manganese-based catalysts for these appHcations exhibit a long life and high catalytic activity. At moderately elevated temperatures, manganese dioxide catalysts (61,62) are used for the complete oxidative degradation of many organic compounds. These catalysts are particularly effective for oxygenated compounds such as alcohols, acetates, and ketones. At a contact time of ca 0.24 s, 95% hydrocarbon destmction efficiency is achieved for ethanol at 204°C ethyl acetate, 218°C propanol, 216°C propyl acetate, 238°C 2-butanone, 224°C toluene, 216°C and heptane, 316°C. Carbon monoxide oxidation occurs at ambient temperatures when no H2O is present. A contact time of ca 0.36 s gives >95% destmction efficiency. Ozone decomposition, at ambient temperatures, that is >99% efficient requites a contact time of ca 0.72 s. Manganese dioxide also catalyzes the decomposition of H2O2 at room temperature and of alkaU metal chlorates at about 270°C.  [c.511]

Ozonation ofAliphatlcs. Although ozone shows Htde tendency to react with saturated hydrocarbons under water treatment conditions, it can react via radical and ionic mechanisms with neat hydrocarbons containing secondary or tertiary hydrogen atoms. Isobutane yields mainly /-butyl alcohol (major) and acetone (minor) cyclohexane gives cyclohexanol and cyclohexanone as the primary oxidation products. Isolated methylene groups are oxidized to carbonyl. For example, ozonation of malonic acid yields oxaHc and hydroxymalonic acids the latter is oxidized further to ketomalonic acid and H2O2. Primary alcohols are oxidized by ozone to carboxyHc acids, H2O2 (major), and aldehydes (minor) secondary alcohols form ketones, which are cleaved by ozone, eg, methyl ethyl ketone yields two moles of acetic acid. With the exception of formic and malonic acids, saturated mono- and dicarboxyHc acids are relatively unreactive toward ozone. GlyoxyHc and malonic acids react at moderate rates and are observed as intermediate products of ozonation of many organics. Acetic and oxaHc acids are relatively stable to ozone and often are the end products of ozonation in water treatment. Acetals are converted to esters in high yield. Simple alkyl monochloramines are readily oxidized by ozone. Ethers are cleaved by ozone yielding alcohols, aldehydes, ketones, and esters ozone also cleaves other compounds such as olefins, acetylenes, disulfides, and those with carbon—nitrogen double and triple bonds.  [c.493]

Ozone also can be used in conjunction with biological filtration through sand, mixed media, or GAG, for removing biodegradable organics produced during ozonation, especially aldehydes, ketones, acids, etc, which can be precursors to THMs, haloacetic acids (HAAs), and other halogenated by-products. For example, ozonation (1.5—4 mg/L) foUowed by GAG filtration produces biological activated carbon (BAG). Partial oxidation of organic matter by ozone can increase biodegradabiHty, although decreasing adsorption efficiency. Oxygen in the carrier gas assists bacteria in oxididation of ammonia and in mineralization of adsorbed organics, providing an efficient process for removing low concentrations of dissolved organic compounds. Ozone plus BAG extends the life of the GAG by reducing the adsorptive load. Ozone can be used again to disinfect the resultant biologically stabilized water prior to chlorination and/or chloramination and distribution.  [c.501]

Tastes and Odors. The origin of most tastes and odors in water suppHes is synthetic organic compounds (eg, phenols) as weU as naturally occurring inorganic (eg, Fe , Mn , and H2S) and organic materials (biologically and chemically altered). The action of algae and actinomycetes on humic materials can produce distasteful water-soluble compounds such as geomycin and 2-methyHsobomeol. Regrowth in the distribution system also can impart taste. Additionally, oxidation during water treatment can generate other odorous compounds (eg, aldehydes). Although many taste and odorous compounds are readily oxidized by ozone (typically 1.5—2.5 ppm), some compounds are more resistant and may require biofiltration or advanced oxidation processes. A pilot-scale study showed that the Peroxone process (O —H2O2) was more effective in removing taste and odor compounds than ozone alone (111).  [c.501]

Removal of Refractory Organics. Ozone reacts slowly or insignificantly with certain micropoUutants in some source waters such as carbon tetrachloride, trichlorethylene (TCE), and perchlorethylene (PCE), as well as in chlorinated waters, ie, ttihalomethanes, THMs (eg, chloroform and bromoform), and haloacetic acids (HAAs) (eg, trichloroacetic acid). Some removal of these compounds occurs in the ozone contactor as a result of volatilization (115). Air-stripping in a packed column is effective for removing some THMs, but not CHBr. THMs can be adsorbed on granular activated carbon (GAG) but the adsorption efficiency is low.  [c.502]

THM andHAA Formation Potential. Trace concentrations of organic materials, such as humic, tannic, and fulvic acids, and synthetic organic chemicals, in treated water react with HOGl and C10 to produce THMs and HAAs. In bromide-containing waters, both chlorinated and brominated THMs and HAAs are formed. Because some of these compounds are carcinogenic, the U.S. EPA has set the maximum contaminant level (MGL) for total THMs (TTHMs) at 0.1 mg/L (117). Ozone-treated waters generally have lower THM and HAA levels as a result of lower THM- and HAA-formation potentials (THMFP andHAAFP).  [c.502]

Ozone Disinfection By-Products. Ozonation of drinking water produces various by-products such as aldehydes, ketones, carboxyHc acids, organic peroxides, epoxides, nitrosarnines, N-oxy compounds, quinones, hydroxylated aromatic compounds, brominated organics, and bromate ion. Although some of these compounds ate potentially toxic or carcinogenic, most bioassay-scteening studies have shown that ozonated water induces substantially less mutagenicity than chlorinated water (165—167). However, further work is necessary to identify and screen (Ames test) ozonation by-products formed under typical water treatment conditions (168). Ozonation by-products ate on the Drinking Water Priority List as candidates for future regulation (169). The Disinfection and Disinfection By-Products Rule proposed by the U.S. EPA will set limits for both disinfectants (excluding ozone) and disinfection by-products (eg, bromate) and requite biofUtration following ozone use (118).  [c.504]

Synthesis. Hydroperoxides have been prepared from several types of peroxygen compounds including hydrogen peroxide or sodium peroxide, ozone, oxygen, and other organic peroxides (45). Hydrogen peroxide (H2O2) and its anions are powerful nucleophiles and react with reagents RX to form ROOH and HX, where X can be sulfate, acid sulfate, alkane- and arenesulfonate, chloride, bromide, hydroxyl, alkoxide, perchlorate, etc. RX can also be an alkyl orthoformate or alkyl carboxylate.  [c.104]

Biospa.l ing. Biosparging is a form of air sparging, but the difference is that the primary purpose of biosparging is to deHver just enough air to meet oxygen requirements for bio remediation. Volatilization of organics may be an added benefit, but it is secondary to oxygen deHvery. An enhancement is to sparge ozone in place of air. Besides providing oxygen for biodegradation, ozone aids in breaking down recalcitrant compounds such as chlorinated  [c.171]

Other ha2ards associated with the use of pulp bleaching agents include their potential for damage resulting from contact with skin or eyes, their abiHty, as oxidizers, to cause fires or explosions upon contact with some kinds of organic matter or certain metals and inorganic compounds, and the possibiHty of explosive decomposition. Specific examples include the combustibiHty of titanium in an atmosphere of dry chlorine and the explosiveness of chlorine dioxide in air at concentrations greater than 10%. Hydrogen peroxide can cause explosions upon contact with organic matter and any one of a number of inorganic substances, including many metal oxides and sulfides. Ozone reacts with many compounds to start fires.  [c.158]

Hundreds of chemical species are present in urban atmospheres. The gaseous air pollutants most commonly monitored are CO, O3, NO2, SO2, and nonmethane volatile organic compounds (NMVOCs), Measurement of specific hydrocarbon compounds is becoming routine in the United States for two reasons (1) their potential role as air toxics and (2) the need for detailed hydrocarbon data for control of urban ozone concentrations. Hydrochloric acid (HCl), ammonia (NH3), and hydrogen fluoride (HF) are occasionally measured. Calibration standards and procedures are available for all of these analytic techniques, ensuring the quality of the analytical results  [c.196]

In a review of ozone air quality models, Seinfeld (33) indicates that the most uncertain part of the emission inventories is the hydrocarbons. The models are especially sensitive to the reactive organic gas levels, speciation, and the concentrations aloft of the various species. He points out the need for improvement in the three-dimensional wind fields and the need for hybrid models that can simulate sub-grid-scale reaction processes to incorporate properly effects of concentrated plumes. Schere (34) points out that we need to improve the way vertical exchange processes are included in the model. Also, although the current models estimate ozone quite well, the atmospheric chemistry needs improvement to better estimate the concentrations of other photochemical components such as peroxyacyl nitrate (PAN), the hydroxyl radical (OH), and volatile organic compounds (VOCs). In addition to the improvement of data bases, including emissions, boundary concentrations, and meteorology, incorporation of the urban ozone with the levels at larger scales is needed.  [c.331]

See pages that mention the term Ozonization of organic compounds : [c.494]    [c.311]    [c.294]    [c.495]    [c.501]    [c.411]    [c.544]   
Organic syntheses Acid anhydrides (1946) -- [ c.26 , c.71 ]