Comparative scientific research on aeration performance of micro nano bubbles and ordinary large bubbles
This paper investigated the aeration performance of micro-nanobubbles(MNBs)generated by using the ultrasonic micro-nanobubble preparation technology and the conventional aeration with large air bubbles.Experimental tests demonstrated that MNBs exhibit significantly enhanced stability and persistence compared to conventional aeration.The oxygen mass transfer coefficient of MNBs was 4.11 times that of conventional aeration,and their oxygen utilization efficiency was 3.30 times higher than that of conventional aeration.Comparative analysis highlighted the superiority of micro-nanobubble aeration over conven-tional aeration in terms of oxygen mass transfer efficiency and oxygen utilization rate.Under the same aeration intensity,MNBs rapidly elevated the dissolved oxygen(DO)concentration in the water,demonstrating their superior oxygen retention capability.After 24 hours of aeration cessation,the DO concentration in water treated with MNBs returned to its initial state,measuring 5.77 mg·L-1,whereas the DO concentration in the water tank aerated with conventional bubbles decreased to 5.82 mg·L-1 after just 1 hour of aeration cessation.Conventional aeration was widely used in environmental water treatment.The insights gained from this study regarding the performance differences of micro-nanobubble aeration are expected to provide theoretical and technological support for improving the effectiveness of water environmental treatment.