OXYGEN TRANSFER BY BUBBLE AERATION

Abstract

Aeration is a process of bringing water in intimate contact with air. While doing so the water absorbs oxygen from the air. Thus dissolved oxygen level is increased in the water. This diAsolved oxygen helps aerobic bacterial decomposition of organic wastes as well as direct oxidation of certain matters. It also helps in removing bad odours-and taste by oxidising and precipitating certain dissolved gases and compounds in the water. Oxygen transfer by bubble aeration has been found much Simpler, economical and easy to adopt methods as compared to many other conventional methods employed so far like air diffusion, trickling beds, spray nozzles and cascades. It has been observed that oxygen transferred to liquid in aera-tion forms a small part and there is possibility of increas-ing it thus bringing a lot of improvement in efficiency and hence economie. In the present study affects of various variables like column height, time of aeration, bubble size, air flow rate on the aeration efficiency of the system have been experi-mentally evaluated. Further a recent concept of overall Oxygen Transfer Coefficient has been used in analysing the experimental results to avoid certain inaccuracies and assumptions. It may be concluded that using optimum values for various parameters and using them suitably the aeration efficiency of the system can be sufficiently increased. Studies done so far can help in visualizing a great scope of much better aeration capacity in the due cource of time.