Laboratory investigations of the deposition of oxidation products of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) to aqueous solutions
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Laboratory experiments were conducted to investigate the deposition to aqueous media of the gas phase oxidation products of the following hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs): HCFC-22 (CClF2H), HFC-41 (CH3F), HCFC-123 (CCl2HCF3), HCFC-124 (CClFHCF3), HFC-125 (CF3CF2H), HFC-134a (CF3CFH2), HCFC-141b (CCl2FCH3), HCFC-142b (CClF2CH3), and HFC-152a (CF2HCH3). Single component experiments were conducted were the oxidation products CF3CFO, COF2, CF3C(O)Cl were exposed under laminar flow conditions to alkaline, acidic, and neutral solutions in a aluminum exposure trough. The anionic composition of the exposure solutions were used to determine the effective deposition velocity. Exposures to neutral solutions were also conducted for irradiated HFC and HCFC/Cl2/air mixtures. The combined single component and irradiated mixture experiments were used to measure the effective deposition velocities of C(O)F2, C(O)FCl, HFC(O), CF(O)OOCF(O), CF3CCl(O), CF3CF(O). The deposition velocities differed by as much as a factor of two with the largest velocities found for C(O)F2 and CF3CF(O). The data were insufficient to determine the extent to which gas and liquid phase resistance controlled the overall deposition. However, the data were used to estimate lower limits for the laboratory aqueous resistance and the results were found to be consistent with the recent conclusions of Wine and Chameides who reported the deposition of the oxidation products to oceans and cloudwater was sufficiently fast that there was little likelihood that the products would be transported to the stratosphere.
KeywordsOxidation Product Deposition Velocity Neutral Solution COF2 Laminar Flow Condition
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