The investigation presented in the report deals with a method for improving the rates of aeration. In order to achieve this objective, small quantities of some organic substances were introduced in the zone of bubble formation. These additives decreased bubble coalescence and improved the rate of transfer because of the substantial increase in the interfacial surface area. The tests were conducted with n-octanol, 4-methyl-2-pentanol and heptanoic acid. At a concentration of 1 ppm the n-octanol and 4-methyl-2-pentanol showed an improvement in the rate of aeration of 70 per cent over that in pure water. At a concentration of only 0.5 ppm n-octanol gave an improvement in the rate of transfer of 30 per cent. Since the design of the aeroator and the agent were not optimized, it may be expected that still better effect could be obtained in a large scale installation. (Author)