Water presaturated with pure carbon dioxide or a mixture of carbon dioxide and oxygen taken in the ratio 75:25 by volume was desorbed into nitrogen or air in a stirred vessel. The resulting changes in the electrical conductivity of water measured during desorption were used to obtain the values of the volumetric mass transfer coefficient with the help of a mathematical model which accounts for RTD, the dynamics of the gas phase, and the decomposition kinetics of carbonic acid. The values of the volumetric mass transfer coefficient obtained by desorbing water presaturated with pure carbon dioxide into nitrogen were found to be higher than the corresponding values obtained when pure carbon dioxide gas was absorbed into water. However, the values of the volumetric mass transfer coefficient obtained by desorbing water presaturated with pure carbon dioxide into air were found to be even higher than the corresponding values obtained when desorption was done into nitrogen. When water presaturated with a 75%-25% carbon dioxide-oxygen mixture was desorbed into air, the values of the volumetric mass transfer coefficient were found to be comparable to the corresponding values obtained when pure carbon dioxide was absorbed into water.