Aerator module development using venturi air injectors to improve aeration efficiency

This article presents information on how to improve aeration efficiency without effecting additional capital and operating costs. Two different configurations of aerator modules were studied using water test. The aerator modules consisted of a number of venturi air injectors connected either in series or in parallel aimed at achieving better aeration efficiencies. The results obtained indicated that the parallel design generally performed better than the series design in terms of transferring oxygen into water, with the oxygen transfer coefficients found to be 9.67 and 5.93 h^-1 for two- and three-aerator parallel modules, as opposed to 4.54, 3.79, and 3.63 h^-1 for one-, two-, and three-aerator series modules. Similarly, higher aeration efficiencies were also observed for the parallel design of the two modules (0.14 and 0.10 kgO₂/kWh) as compared to those in the series design (0.07, 0.06, and 0.06 kgO₂/kWh). The parallel module with two air injectors achieved the highest aeration efficiency (0.14 kgO₂/kWh), which was two times the highest efficiency reached by the series modules (0.07 kgO₂/kWh). In the same way, the oxygenation capacities were also significantly higher for parallel modules (0.22 and 0.15 kgO₂/h) than for series modules (0.10, 0.09, and 0.09 kgO₂/h). The data suggest that more research effort should be invested in exploring the possibility of using inexpensive aerators through better designs of the air injector complex in order to develop inexpensive aeration systems.