The efficiency of oxygen transfer depends on many factors including type, size and shape of diffusers and tank geometry. In this paper, the effect of the depth of water in the tank and, the extension of coverage area of diffusers on each of oxygen transfer capacity (OC), efficiency (E) and, on a percentage of oxygen absorption (δ) is tested. Experimental procedure is adopted to evaluate the effect of these parameters. The results of the study showed that, both of a depth of water and, the expand of coverage area of diffuser had a significant effect on the tested parameters. The values of oxygen transfer capacity (OC) and the efficiency (E) were ranging from (18 to 170 grO2/m3 tank. hr) and from (2 to 17 grO2/m3air) respectively, depending on the depth of water in tank and the ratio of diffusers coverage area. The value of an oxygen absorption percentage was ranging from (0.45-5.4%) depending on the circumstances of the test. Individual mathematical models to describe the effect of each parameter were also derived. The exponentional form of derived equation proved to be efficient to describe the effect of a depth of water on oxygen transfer capacity (OC) whereas; the linear form of the equation was good enough in representing the effect of the other parameters.
Keywords: oxygen transfer capacity, absorption, diffusers, water depth, KLa, efficiency, diffusers coverage area