Ozone in Water

Ozone can be analyzed by titrimetry, direct and colorimetric spectrometry, amperometry, oxidation—reduction potential (ORP), chemiluminescence, calorimetry, thermal conductivity, and isothermal pressure change on decomposition. The last three methods ate not frequently employed. Proper measurement of ozone in water requites an awareness of its reactivity, instabiUty, volatility, and the potential effect of interfering substances. To eliminate interferences, ozone sometimes is sparged out of solution by using an inert gas for analysis in the gas phase or on reabsorption in a clean solution. Historically, the most common analytical procedure has been the iodometric method in which gaseous ozone is absorbed by aqueous KI. 

In this reaction, iodine is liberated from a solution of potassium iodide. This reaction can be used to assess the amount of ozone in either air or water. For determination in air or oxygen, a measured volume of gas is drawn through a wash bottle containing potassium iodide solution. Upon lowering the pH with acid, titration is effected with sodium thiosulfate, using a starch solution as an indicator. There is a similar procedure for determining ozone in water. 

Butkovic, V., Klasinc, L., Orhanovic, Turk, J., Glisten, H. (1983) Reaction rates of polynuclear aromatic hydrocarbons with ozone in water. Environ. Sci. Technol. 17, 546-548. 

B. Langlais, D.A. Reckhow, and D.R. Brink, Ozone in Water Treatment Application and Engineering, AWWA Research Foundation and Lewis Publishers, Chelsea, 1991. 

Solubility data for mucus are not available, but Table 7-1 indicates that the Henry s law constant for ozone in water under the conditions of the lung is 9,700. Solubility data for pure ozone and other physical properties are available from various sources. Air Quality Criteria for Photochemical Oxidants reports an ozone solubility of 0.494 ml/ 100 ml of water at 0 C for ozone at 760 mm Hg extrapolation of data from Thorp indicates 1.09 g/liter of water at 0 C and approximately 0.31 g/liter of water at 37 C for 100% ozone. The value for 37 C agrees closely with the solubility calculated from the Henry s law constant for pure ozone at 760 mm Hg. 

The diffusivities of ozone in mucus, tissue, and water are unknown. As an approximation, the diffusivity of oxygen in water (2.5 x 10 cm /s) may be used for the diffusivity of ozone in water and in the mucus layer. Although reactivities of ozone in mucus and tissue are unknown, the results of Alder and Hill and Hoigne and Bader, which describe the decomposition of ozone in aqueous solutions, may be used as a first approximation. 

Chemical/Physical. Ozonation in water at 60 °C produced 7-formyl-1-indanone, 1-indanone, 7-hydroxy-l-indanone, l-indanone-7-carboxylic acid, indane-l,7-dicarboxylic acid, and indane-1-formyl-7-carboxylic acid (Chen et al, 1979). Wet oxidation of acenaphthene at 320 °C yielded formic and acetic acids (Randall and Knopp, 1980). The measured rate constant for the gas-phase reaction of acenaphthene with OH radicals is 8.0 x 10 " cmVmolecule-sec (Reisen and Arey, 2002). 

Chemical/Physical. Ozonation in water at 60 °C produced 1,8-naphthalene dialdehyde, 1,8-naphthalene anhydride, 1,2-epoxyacenaphthylene, 1-naphthoic acid, and 1,8-naphthaldehydic acid (Calvert and Pitts, 1966). 

In water, carbofuran reacted with OH radicals at a first-order rate constant of 2.2 x 10 /M-sec (Mabury and Crosby, 1996a). Benitez et al. (2002) reported an apparent pseudo-first-order rate constant ranging from 5.1 x 10to 19.5 x lO Vsec for the reaction of carbofuran with ozone in water. When ozone and UV radiation was used to study the degradation kinetics, the pseudo-first-order rate constant was 22.8 x 10 Vsec. Similarly, the oxidation of carbofuran by Fenton s reagent and UV radiation ranged from 17.2 x 10 to >200 x lO Vsec. 

Langlais, B Reckhow, DA Brink, DR. Ozone in water treatment application and engineering. Boca Raton Lewis Publishers 1991. 

Epoxidation of cyclooctene has been shown, using ozone in water where the products were easily recovered by phase separation (Shu et al., 1995). 

Brandt and van Eldik30 review of the chemistry of sulfur(IV) oxidation, with emphasis on the catalytic role of metal ions such as Fe2+. We consider here only a simplified summary of the principal atmospheric oxidation processes. It is likely that oxidation is effected primarily through the action of hydrogen peroxide or ozone in water droplets in clouds, through the photochemical effect of ultraviolet light, or by heterogeneous catalysis of the S02-02 reaction by dust particles 9,30,31... 

Properties of Ozone. 1. Dissolve ozone in water. Does the solution have an odour ... 

Langlais B, Reckhow D A, Brink D R (1991) Ozone in Water Treatment Application and Engineering, American Water Works Association Research Foundation, Denver, Lewis Publishers Inc., Michigan. 

Table 2-1 Typical initiators, promoters and scavengers for decomposition of ozone in water (Staehelin and Hoigne, 1983 Xiong and Graham, 1992).

Comparison of the initial reaction with H02 (k9 = 2.2 106M s 1) and with OH (k[ = 70 M 1 s 1) shows that in the 0,/H202 -system the initiation step by OH is negligible. Whenever the concentration of hydrogen peroxide is above 10 7 M and the pH-value less than 12, H02 has a greater effect than OH has on the decomposition rate of ozone in water. 

Staehelin J, Hoigne J (1982) Decomposition of Ozone in Water Rate of Initiation by Hydroxide Ions and Hydrogen Peroxide, Environmental Science Technology 16 676-681. 

This chapter provides an overview and guidance on the various applications of ozone in water and waste water treatment, where full-scale facilities exist and it has been demonstrated that ozonation is effective and economical. 

Bigot V, Luck F, Paillard H, Wagner A (1994) Evaluation of advanced oxidation processes for landfill leachate treatment, in Proceedings of the international ozone symposium Application of ozone in water and wastewater treatment , Bln A K (ed.) Warsaw Poland May 26-27 330-343. 

Masschelein W J (1994) Towards one century application of ozone in water treatment scope - limitations and perspectives, in A K Bin (ed.) Proceedings of the International Ozone Symposium Application of Ozone in Water and Wastewater Treatment May 26-27 11-36, Warsaw Poland. 

In the presence of ozone in water, ozone diffuses through the membrane into the reaction chamber. The rate of flow is dependent on the partial pressure of ozone. In order to avoid a depletion of ozone molecules at the surface of the membrane, the electrode should be immersed into a continuous flow. 

Bader H, Hoigne J (1981) Determination of Ozone in Water by the Indigo Method, Water Research 15 449-461. 

Gottschalk C, Schweckendiek J, Beuscher U, Hardwick S, Kobayashi M, Wikol M (1998) Production of high concentrations of bubble-free dissolved ozone in water - the fourth international symposium on ULTRA CLEAN PROCESSING OF SILICON SURFACES, UCPSS 98 September 21 -23, Oostende Belgium 59-63. 

Stanley J H, Johnson J D (1979) Amperiometric Membrane Electrode for Measurement of Ozone in Water, Analytical Chemistry 51 2144-2147. 

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