Description of the project: "THE AIM OF THE PROJECT WAS THEORETICAL AND EXPERIMENTAL RESEARCH ON OXYGENATION PROCESS IN BIOLOGICAL WASTEWATER TREATMENT. IT HAS DEVELOPED MODELS FOR FLUID FLOW, IT HAS ESTABLISHED DIFFUSION/DISPERSION EQUATIONS, SIMILITUDE CRITERIA AND IT HAS DETERMINED MASS TRANSFER COEFFICIENT FOR DIFFERENT AERATION EQUIPMENT. THEORETICAL RESULTS WAS COMPARED WITH EXPERIMENTAL ONES. "