Showing papers in "Ozone-science & Engineering in 1996"
TL;DR: A joint meeting of members of the Quality Assurance Committees of the International Ozone Association Pan American Group (PAG), European-African Group (EAG), and Nippon Islands Group (NIG) was held in Oxford, Ohio on November 8 and 9, 1995 as mentioned in this paper.
Abstract: A joint meeting of members of the Quality Assurance Committees of the International Ozone Association Pan American Group (PAG), European-African Group (EAG), and Nippon Islands Group (NIG) was held in Oxford, Ohio on November 8 and 9, 1995. The purpose of the meeting was to establish a single, shared guideline for ozone concentration measurement in the gas phase and, in particular, from commercial ozone generators.
283 citations
TL;DR: A detailed review of published applications of ozone for treating many types of industrial wastewaters is presented in this article, where ozone is used as a replacement bleaching agent for paper pulp to eliminate the discharge of halogenated effluents.
Abstract: This paper presents a detailed review of published applications of ozone for treating many types of industrial wastewaters. Applications of ozone technologies to control pollution in full‐scale industrial wastewater treatment plants in the areas of recycling marine aquaria, electroplating wastes, electronic chip manufacture, textiles, and petroleum refineries, are discussed. The rising acceptance of ozone as a replacement bleaching agent for paper pulp to eliminate the discharge of halogenated effluents from pulp bleaching plants also is traced. Newer applications for ozone in treating rubber additive wastewaters, landfill leachates, and detergents in municipal wastewaters are summarized briefly. The combination of ozone oxidation followed by biological treatment has been installed full‐scale at a large German industrial chemical complex. Ozone coupled with ultraviolet radiation and/or hydrogen peroxide (advanced oxidation) is being utilized to destroy organic contaminants in groundwaters at muni...
223 citations
TL;DR: In this paper, it was shown that using transition metals, especially Mn(II) and Ag(I), during ozonation of humic substances in water allows important reductions in the content of organic matter.
Abstract: It is shown that using transition metals, especially Mn(II) and Ag(I), during ozonation of humic substances in water allows important reductions in the content of organic matter. Characterization of the organic compounds resulting from ozonation was made by concentrating the sample through liquid-liquid extraction or derivation with PFBOA.HCl, along with the GC/MS and GC/ECD techniques. In total, 110 different organic compounds were identified using GC/MS; mainly carboxylic acids, aromatics, hydrocarbons, aldehydes, ketones, and furan-carboxylic acids. The percentages of elimination or formation levels reached during ozonation are discussed.
97 citations
TL;DR: In this article, the combined method of ozonation and subsequent biodegradation of both synthetic and real textile wastes was explored in laboratory-scale studies, where two kinds of industrial wastes were simulated for effluents from dyehouse and washing machines.
Abstract: Textile wastewaters are known to be highly resistant to biodegradation under both natural and wastewater treatment plant conditions. However, ozonation can be used to increase the biodegradability of the biologically resistant compounds. The combined method of ozonation and subsequent biodegradation of both synthetic and real textile wastes was explored in laboratory-scale studies. Two kinds of industrial wastes were simulated for effluents from dyehouse and washing machines. Upon determining the ozonation conditions of synthetic wastes, the real industrial wastes were investigated. The real textile wastewater was taken from textile factories, located in odź , Poland, from subsequent stages of textile processing; dyeing, washing, rinsing and from an equalizer tank. Ozonation was carried out in a lab-scale bubble column sparged reactor, while the biological degradation proceeded in a trickle bed biofilter.
89 citations
TL;DR: In this article, a batch type ozone experiments conducted on aquatic humic substances solutions spiked with bromide ion were developed to evaluate the importance of various parameters that may affect the formation of bromate ion during ozonation.
Abstract: Batch type ozone experiments conducted on aquatic humic substances solutions spiked with bromide ion were developed to evaluate the importance of various parameters that may affect the formation of bromate ion during ozonation. The nature of the NOM, the alkalinity, the bromide ion content and the presence of ammonia were found to significantly affect the bromate ion production. Temperature and pH can be considered as minor factors. The ozonation of a clarified surface water using a continuous flow ozone contactor have shown that the addition of a low quantity of ammonia (0.05 to 0.1 mg/L NNH4 +) appeared to be an interesting option for controlling the bromate formation. On the contrary, the addition of hydrogen peroxide may enhance or reduce the bromate ion production, depending on the applied hydrogen peroxide/ozone ratio.
50 citations
TL;DR: In this paper, a computer model based on the establishment of mass balance equations and on the model of fluids flow "stirred tank in series" was developed in order to calculate the ozone transfer coefficient kLa and kinetic constant kc of ozone consumption by water.
Abstract: A computer model based on the establishment of mass balance equations and on the model of fluids flow “stirred tank in series” was developed in order to calculate the ozone transfer coefficient kLa and kinetic constant kc of ozone consumption by water. On the basis of experimental data, the correlation for gas holdup eg and bubble diameter dvs, were proposed and used to calculate the specific interfacial area a. The liquid-phase mass transfer coefficient kL for ozone was evaluated from a and the kLa data.
50 citations
TL;DR: A one-year research on the formation of bromate ion and organobrominated compounds by water ozonation was initiated recently between four French water treatment companies (C.G. Eaux, Lyonnaise des Eaux-Dumez, SAUR and SAGEP), one Spanish company (SGAB), the IARC, the KIWA, the WRc and the University of Poitiers as discussed by the authors.
Abstract: A one-year programme of research on the formation of bromate ion and organobrominated compounds by water ozonation was initiated recently between four French water treatment companies (C.G. Eaux, Lyonnaise des Eaux-Dumez, SAUR and SAGEP), one Spanish company (SGAB), the IARC, the KIWA, the WRc and the University of Poitiers. The programme comprises five aspects. The objective of this paper is to present the entirety of data from the following aspects: (I) inventory of the bromate ion content in distributed drinking water, and (ii) study of the evolution of bromate ion during the water treatment process.
39 citations
TL;DR: In this article, a low pressure lamp which emits radiation predominantly at < 200 nm was more effective than a medium pressure lamp that emits radiation at 254 nm, since bromate ion has a peak absorbance of about 195 nm.
Abstract: Bromate ion destruction by UV irradiation using either a low pressure mercury lamp or a medium pressure mercury lamp has been evaluated. A low pressure lamp which emits radiation predominantly at < 200 nm was more effective than the UV lamp which emits radiation at 254 nm, since bromate ion has a peak absorbance of about 195 nm. Bromate ion was shown to be reduced to bromide ion with bromine as an intermediate. Bromate ion destruction using a low pressure mercury lamp (< 200 nm) ranged from 3 to 38% for doses ranging from 23 to 228 mW-s/cm2; 7-46% destruction was achieved using a medium pressure lamp with initial bromate ion concentrations of 11-38 μg/L and doses ranging from 60 to 550 mW-s/cm2. A new innovative electric arc discharge method also has been evaluated and compared with UV irradiation. The electric arc discharge method destroyed 12-45% bromate ion for doses ranging from 130 to 1300 mW-s/cm2.
36 citations
TL;DR: In this article, the effects of oxalic acid on coagulation in high dissolved organic carbon synthetic waters with model particles were evaluated, and the results indicated that the presence of oxic acid adversely affects the removal of turbidity and organic carbon.
Abstract: Ozonation breaks long chain natural organic matter (NOM) into smaller, more oxygenated compounds such as oxalic acid. The purpose of this study was to evaluate the effects of such transformations on coagulation in high dissolved organic carbon synthetic waters with model particles. Results indicate that the presence of oxalic acid adversely affects the removal of turbidity and organic carbon by coagulation and filtration. The results also show that larger (higher molecular weight) organic matter is easier to remove by coagulation than lower molecular weight organic matter. In both cases, ozonation results in an increase in the optimum coagulant dose or a decrease in the amount of turbidity and TOC removal at a given coagulant dose.
26 citations
TL;DR: In this paper, the decomposition of several non-biodegradable phenols by the UV/O3 and ozonation processes was studied and compared under various solution pH values, O3 input mass flow rates and UV intensities to investigate the removal efficiencies of reactants and organic intermediates.
Abstract: The decomposition of several non‐biodegradable phenols by the UV/O3 and ozonation processes was studied and compared under various solution pH values, O3 input mass flow rates and UV intensities to investigate the removal efficiencies of reactants and organic intermediates. The decomposition rate of phenols by the UV/O3 process was found to increase with increasing O3 input dosage, light intensity and solution pH value. The mineralization efficiencies of phenols in aqueous solution would be above 98% under adequate reaction conditions within three hours, but would be retarded for alkaline solutions because of the dissolution of CO2 formed by mineralization of phenols. The increment of ozone input dosage had little effect on the mineralization of organic intermediates at the latter course of the reaction. The order of the decomposition rate of the phenols used in this research was 2,4‐dichlorophenol > 2‐chlorophenol > 2‐nitrophenol for low and neutral pH solutions, whereas they were nearly alike f...
25 citations
TL;DR: In this paper, the oxidation of trichlorobenzene (TCB) in a continuously-flowing completely mixed reactor (CFCMR) operated at steady-state conditions using a hydraulic retention time of 10 minutes was studied.
Abstract: The oxidation of 1,3,5‐trichlorobenzene (TCB) by ozone, ozone/UV, ozone/H2O2 and ozone/UV/H2O2 was studied. All studies were conducted in a continuously‐flowing completely mixed reactor (CFCMR), operated at steady‐state conditions using a hydraulic retention time of 10 minutes. The greatest removal of TCB using ozone/H2O2 treatment was achieved using a H2O2 concentration of 60 μM. At low pH values (approx. 2) ozone/UV performed significantly better than either ozone alone or ozone/H2O2. However, at circumneutral pH, the removal efficiencies of TCB by ozone/UV and ozone/H2O2 and ozone/UV/H2O2 were essentially equal (∼ 97% for TCB). The removal efficiency of ozone alone was ∼93% for TCB. At high pH (> 9) there was no advantage in supplementing ozone with either UV or H2O2 as the removal efficiencies for all processes studied were essentially equal. The effect of humic acid and bicarbonate on the removal of TCB was studied. At 1.6 mg/L humic acid, 92–95% of the TCB was oxidized by the processes stud...
TL;DR: In this article, the ozone decomposition on glass and silica surfaces is studied by means of nonporous particles in a fixed bed (sand, glass bead, crushed glass bead or silica), and the influence of gas velocity, particle diameter and reactor volume is investigated.
Abstract: Ozone decomposition on glass and silica surfaces is studied by means of non‐porous particles in a fixed bed (sand, glass bead, crushed glass bead, silica). Influences of gas velocity, particle diameter and reactor volume are investigated. Ozone is produced by a silent discharge generator. A model considering the geometric characteristics of material is used so that the ozone decomposition rate per unit of surface area is identified. The decomposition reaction is represented by means of an apparent first‐order kinetic constant. The high dependency of the apparent kinetic constant on the surface area, for given flow rates, suggests that the ozone decomposition mechanism is not simple. Due to the values of the apparent first order kinetic constant, the existence of catalytic species produced by the ozone generator, as well as excited ozone and/or oxygen species, are considered, by means of several models, to explain the experimental results.
TL;DR: In this paper, the authors evaluated granular activated carbon (GAC) beds and found that after 500 to 1000 daily loading and regeneration cycles, one field GAC lost 35% of its micropore volume, and 17-35% of the capacity to adsorb several VOCs.
Abstract: The Pennsylvania State University is researching an advanced oxidation (AO) system for controlling volatile organic compounds (VOCs) (Cannon et al. 1994). The system includes an air‐phase photolytic chamber, an air/water stripping tower, and granular activated carbon (GAC) beds, and the work herein describes he evaluation of the GAC beds. Field GACs have been evaluated, which had previously been loaded with VOCs and regenerated with AO for several years at several full scale installations. Full scale response then was simulated in laboratory‐scale experiments. Results revealed that following 500 to 1000 daily loading and regeneration cycles, one field GAC lost 35% of its micropore volume, and 17–35% of its capacity to adsorb several VOCs. Under another condition, for a furniture coating GAC, 80% of the micropore volume was lost after several years of loading and reactivation cycles, and 23 to 63% of the VOC adsorption capacity was lost. Laboratory results revealed that prolonged AO regeneration d...
TL;DR: In this article, the efficiency of ozone and ozone in combination with hydrogen peroxide, for the degradation of five herbicides: Atrazine, Benazolin, Bentazone, Imazapyr and Triclopyr, under controlled laboratory conditions was investigated.
Abstract: The efficiency of ozone, and ozone in combination with hydrogen peroxide, for the degradation of five herbicides: Atrazine, Benazolin, Bentazone, Imazapyr and Triclopyr, under controlled laboratory conditions was investigated. Experiments were conducted at pH 7.5 in a bubble contactor column with a raw lowland surface water spiked with initial active ingredient concentrations of 2 μg/L. Mean consumed ozone doses were approximately 1, 2 and 3 mg O3/L. Hydrogen peroxide was added simultaneously to the application of ozone in a series of six mass ratios, between 0.0 and 1.0, with each of the consumed ozone doses. The results demonstrated a greater but varying removal of all herbicides achieved with increasing consumed ozone and applied hydrogen peroxide doses.
TL;DR: The fluorochromization using 3′,6′-diacetylfluorescein (FDA) proved to be a suitable method for the detection of an alteration in permeability of the cell membranes and an inactivation of metabolic activity.
Abstract: Cell suspensions of Escherichia coli as a model for bacterial populations in wastewaters were treated with ozone as a disinfectant in a continuously operated pilot plant with a plug flow reactor. Suspensions with an initial number of CFU (colony forming units) of 108 mL−1 were ozonized with ozone concentrations up to 12 mg/L. Metabolic activities and membrane functions break down with increasing ozone concentrations. The fluorochromization using 3′,6′-diacetylfluorescein (FDA) proved to be a suitable method for the detection of an alteration in permeability of the cell membranes and an inactivation of metabolic activity. By fluorescence microscopic and photometric investigations it could be clearly demonstrated that, in the case of disinfection with ozone, inactivation of the cells includes first of all a damage of the cell membranes. In contrast to the determination of the number of CFU, fluorochromization allows the detection of alteration in metabolic activities.
TL;DR: In this article, the catalytic effect of dielectric packings inside the discharge gap on the yield of ozone generation was studied under silent discharge conditions, and Porous silica of developed internal surface and quartz glass grains were used as the packings.
Abstract: The catalytic effect of dielectric packings inside the discharge gap on the yield of ozone generation was studied under silent discharge conditions. Porous silica of developed internal surface and quartz glass grains were used as the packings. In the presence of coarser grains of both materials, higher ozone concentrations and higher energy efficiency were observed than with the finer ones. Porous silica was found to be more effective than quartz glass. The higher activity of silica arises from the surface structure rather than from its porosity.
TL;DR: In this article, the use of ozone in the water supply service of Florence (Italy) has been reported to be particularly efficient for controlling bromates and brominated organic byproducts.
Abstract: This paper reports on the use of ozone in the Water Supply Service of Florence (Italy). The addition of hydrogen peroxide at the end of ozonation treatment has proved particularly efficient for controlling bromates and brominated organic byproducts. Significant differences regarding the formation of oxygenated organic compounds were not observed.
TL;DR: In this article, the authors present results focused on: 1) precision of UV meter readings, 2) accuracy of the wet-test meter or the UV meter, and 3) expected range in percent difference between UAV readings and KI wet-chemistry test ozone concentration results for the particular type of UAV and wet test meter used in the tests.
Abstract: Formal ozone system power-production tests conducted at ten (10) different ozone installations have resulted in over 100 comparative UV meter versus KI wet-chemistry ozone concentration tests for fifteen (15) individual UV meters. The wet-chemistry tests were conducted by different individuals, including the ozone generator manufacturer's technician and owner's staff. In all cases, the tests were either conducted or witnessed by one of the authors. This paper presents results focused on: 1) precision of UV meter readings, 2) accuracy of the wet-test meter or the UV meter, and 3) expected range in percent difference between UV meter readings and KI wet-chemistry test ozone concentration results for the particular type of UV meter and wet-test meter used in the tests.
TL;DR: In this paper, ozone has been used as a substitute for chlorine in the bleaching of pulp for paper making since 1949, but it has only been since 1992 that ozone has begun to reach its full-scale commercial potential.
Abstract: Although ozone has been studied seriously as a substitute for chlorine in the bleaching of pulp for paper making since 1949, it has only been since 1992 that ozone has begun to reach its full‐scale commercial potential. In this evolution, ozone has been aided immeasurably by environmental pressures to diminish the discharge of halogenated organics in pulp mill wastewaters. Thanks to the incorporation of ozonation into bleach processes, not only is the creation of halogenated organics minimized (and even eliminated in some cases), but this allows some of the processing liquors to be recovered and volumes of bleach plant effluents to be reduced. As a consequence, this not only decreases the volume of wastewater being discharged to the receiving water bodies, but also increases the potential for the Totally Effluent‐Free (TEF) bleached pulp mill to become a future reality. Ozone's evolution in this rapidly growing industry is traced, and some characteristics of the 14 full‐scale pulp mills currently...
TL;DR: In this paper, a simplified kinetic reaction rate model is presented for bromate ion formation in contactor hydraulics and two extreme reactor types are compared: completely stirred tank (CSTR) and plug flow reactors (PFR).
Abstract: This paper presents a simplified kinetic reaction rate model which enables the evaluation of various contactor hydraulics on bromate ion formation. Two extreme reactor types are presented: completely stirred tank (CSTR) and plug flow reactors (PFR). The kinetic modeling has been based on reactions and rate constants for molecular ozone mechanisms. At this stage, the work presented does not take into account the formation and reaction of hydroxyl radicals in the reaction pathway. However, for further in-depth modeling consideration, it is questionable that no hydroxyl radicals are formed. Similar bromate ion levels were predicted with a PFR and a CSTR for similar operating conditions in the case of predominantly molecular ozone reactions. However in most cases, a CSTR will require a much higher Cτ (product of the residual ozone concentration and the hydraulic residence time) than a plug flow reactor in order to achieve similar treated water quality goals.
TL;DR: Except for one mechanical pulp mill effluent, all effluents ozonized showed rapid and selective destruction of their acute toxicity, juvabiones (JB), and resin and fatty acids (RFAs) over biological and chemical oxygen demand (BOD and COD) by ozone.
Abstract: Eighteen effluent types from seven thermomechanical (TMP), chemithermomechanical (CTMP), bleached chemimechanical (BCMP), and kraft pulp mills were treated in the laboratory with ozone alone or ozone in conjunction with aerobic biological treatment. Except for one mechanical pulp mill effluent, all effluents ozonized showed rapid and selective destruction of their acute toxicity, juvabiones (JB), and resin and fatty acids (RFAs) over biological and chemical oxygen demand (BOD and COD) by ozone. For acute toxicity and RFA/JB removal, aerobic biotreatment of mechanical mill effluent streams produced additive but not synergistic effects when combined with ozone treatment. Ozonation of biotreated kraft effluents yielded substantial decreases in the biologically recalcitrant residual adsorbable organic halogens (AOX), converted COD to BOD, and usually produced large decreases in color.
TL;DR: In this article, the rates of elementary reactions involving electron-molecule collisions which result in chemical transformations are proportional to the charge passing through the reaction chamber and the gap width.
Abstract: The rates of elementary reactions involving electron-molecule collisions which result in chemical transformations are proportional to the charge passing through the reaction chamber and the gap width. A theoretical method is presented which allows calculation of the rate coefficients of these elementary steps. It was assumed that the energy distribution of the collisions is determined by the electric field, and the types and spatial distributions of the gaseous reactants. For validation of the theory, its results are compared with those obtained from traditional kinetic experiments.
TL;DR: The surface water treatment plants in Anglian Water are being upgraded in order to more reliably meet the requirements of the EEC Drinking Water Directive as discussed by the authors, and Ozone and additional GAC filtration capacity are being installed at 11 waterworks treating river and reservoir water, with capacities ranging from 11 to 360 ML/d.
Abstract: The surface water treatment plants in Anglian Water are being upgraded in order to more reliably meet the requirements of the EEC Drinking Water Directive. Ozone and additional GAC filtration capacity are being installed at 11 waterworks treating river and reservoir water, with capacities ranging from 11 to 360 ML/d. The installations and reasons for the plant designs are discussed.
TL;DR: In this article, a presentation rassemble a la fois les besoins et les experiences du fournisseur d'equipements de generation d'ozone and de lutilisateur de ces memes equipements.
Abstract: Cette presentation rassemble a la fois les besoins et les experiences du fournisseur d'equipements de generation d'ozone et de l'utilisateur de ces memes equipements Les specification techniques du gaz de procede pour la generation de l'ozone, les caracteristiques des solutions variantes, les resultats obtenus sur l'installation industrielle et l'etablissement de criteres pour des installation futures sont decrits Le cas particulier etudie et les quantites requises d'ozone sont detailles afin de permettre une comprehension complet et les contraintes sur le choix du systeme Le passage d'un procede a l'air vers un procede a l'oxygene est particulierement souligne L'etude presente l'evaluation conjointe effectuee par Bristol Water PLC et Ozonia pour le choix du gaz de procede sur l'installation de Purton en utilisant l'experience acquise sur l'installation de Littleton, ainsi que l'assistance technique lors de l'etablissement du schema de developpement de l'installation de Purton
TL;DR: In this article, the coal tar lining of water mains was removed and polynuclear aromatic hydrocarbons fronted the coal-tar lining of the main line of a water main.
Abstract: (1996). Research note: Remobilization of polynuclear aromatic hydrocarbons front the coal tar lining of water mains. Ozone: Science & Engineering: Vol. 18, No. 6, pp. 517-519.
TL;DR: In this article, the influence of bromide ion on the distribution and variation of organohalogen DBPs was examined, and the results of factor analysis lead clearly to the interpretation that the bromides ion was strongly correlated with brominated THMs and less strongly with Brominated HAAs (haloacetonitriles).
Abstract: Ozonation of water containing bromide ion (Br−) leads to the formation of brominated disinfection byproducts (DBPs). The purpose of this study was to examine the influence of bromide ion upon the distribution and variation of organohalogen DBPs. Bromide ion concentration had a negative effect on chloroform formation as opposed to increased formation of brominated trihalomethanes (THMs). The results of factor analysis lead clearly to the interpretation that the bromide ion was strongly correlated with brominated THMs and less strongly with brominated HANs (haloacetonitriles). Compared to THMs and HANs, brominated HAAs (haloacetic acids) demonstrated a relatively weak correlation to bromide ion concentration. The addition of alkalinity enhanced the formation of chloroform when ozonation time was 10 to 30 minutes, while concentrations of other bromide ion-containing THMs decreased with increasing alkalinity.
TL;DR: In this article, the rate of a chemical reaction occurring in a silent electric discharge is dependent on the electric charge passing through the gas, and the application of purely sinusoidal alternating current to the system allows deduction of the time dependence of the voltage drops across various circuit elements.
Abstract: The rate of a chemical reaction occurring in a silent electric discharge is dependent on the electric charge passing through the gas. In the knowledge of the electrical characteristics of the circuit and its elements (i.e., the ohmic resistance and capacitance), the composition and the pressure of the gas, the electric charge involved in the discharge can be calculated. The application of a purely sinusoidal alternating current to the system allows deduction of the time dependence of the voltage drops across various circuit elements and also the time dependence of the current. Experiments were conducted with two reactor types (static and tubular flow) and their electrical characteristics were varied to test the results of the calculations, which were thereby confirmed.
TL;DR: In this paper, a method for continuous monitoring of ozone in water by using the Indigo colorimetric technique is presented, and the details of an instrument developed and used for this purpose are explained.
Abstract: This paper presents a method for continuous monitoring of ozone in water by using the Indigo colorimetric technique. The details of an instrument developed and used for this purpose are explained. Data obtained using the continuous ozone reading equipment in monitoring the ozone levels are presented. The instrument also can be used to measure the decay of ozone in ozonated waters, continuously giving a very accurate measure of ozone decay coefficients.
TL;DR: In this paper, a heat transfer model has been developed to enhance the understanding of influence of operating parameters on ozone production in a cold plasma reactor, and the model predictions are in qualitative agreement with experimental results obtained on oxygen-fed cold plasma reactors.
Abstract: Heat dissipation has a bad influence on ozone production reactor performance. In order to enhance our understanding of influence of operating parameters, a heat transfer model has been developed. Model predictions are in qualitative agreement with experimental results obtained on oxygen‐fed cold plasma reactors. Moreover, incidences of the local climate and of the cooling fluid temperature level on the ozone production cost are emphasized.
TL;DR: In this article, the effects of system parameters on the ozone mass transfer rate were examined and the reduction effect of interfacial resistance on the absorption rate was most significant for the situation with the larger values of Mm and Mn as well as with higher pH values.
Abstract: A theoretical analysis is performed employing the film model for the isothermal absorption and self-decomposition of ozone in aqueous solutions with interfacial resistance, which is inversely proportional to the interfacial mass transfer coefficient ks. A closed-form solution has been obtained. The effects of system parameters on the ozone mass transfer rate are examined. These parameters include the interfacial resistance (1/ks), the acidic and basic self-decomposition reaction rate parameters (Mm 0.5, Mn 0.5.; Mm = [2DAkmCAi m-1/(m+1)]/(kL 0)2, Mn=(2DAknCAi n-1/(n+1))/(kL 0)2, the reaction orders (m,n), the pH value of solution, and the liquid-phase mass transfer coefficient (kL 0). The results indicate that the reduction effect of the interfacial resistance on the absorption rate is most significant for the situation with the larger values of Mm and Mn as well as with higher pH values. Also, for any particular finite value of kL 0/ks, the reduction effect encountered is greater for a gas liqui...