Abstract
Two water purification techniques in wide-closed water area polluted by waste water were developed using two types of aeraters which could generate a large quantity of micro-bubbles, which diameters are less than 100 micron, and form large-scale circulating secondary flows in the whole water area. The efficiency of the techniques was experimentally proved for two kinds of waste water quality in fields.The results indicate that the both aeration systems play a great important role of waste water purification and the growth of animals and plants.
