Development of a Water Purification System via Enhanced Aeration*-1. Phenomenological Characteristics

摘要

River, lake and reservoir environments have beendrastically deteriorated along with the economical and industrialdevelopments of the country. The change of the human life style isalso another important factor affecting on the pollution of waterenvironments. One of the most effective and economical ways toconserve, improve and purify the water environment should be theenhancement of the dissolved oxygen concentration by aeration.An enhanced aeration system is developed to cope with lowefficiency, scale-up difficulty and restricted versatilityaccompanied with conventional aeration systems. The developedaeration system utilises the centrifugal shear stress to generate anenormous number of fine air bubbles and to establish the highpropagation performance of mixing energy. The pressure loss ofthe cyclone-like aerator is deduced from the dimensional analysisand experimental works, which serves to scale up to aerationsystem and to evaluate the energy consumption of the wholesystem. The performance of the aeration system is experimentallyevaluated in terms of the maximum aeration rate and the dissolvedoxygen transfer rate. The former is confirmed to take a remarkablyhigher value and the latter is expected to much faster than those inconventional aeration systems.