Applied Research of Micro-nano-bubble Aeration Technology on Treatment of Domestic Sewage

As a new type of aeration technology,micro-nano-bubble aeration was gradually used in the water treatment.From the actual practice,a comparison study on treatment efficiency of domestic sewage between the micro-bubble aeration and the bottom aeration was carried out.The results showed that micro-bubble aeration technology could make higher degradation efficiency on CODCrin sewage than the bottom aeration under the same gas flow.The removal rate of the former was 90.8%,while the later was 86.4%.The concentration of SS could get the minimum in the 8 h when using the micro-bubble aeration and its removal rate was 96.3%,while the bottom aeration needed 12 h to reach the minimum and the removal rate was only 89%.With the micro-bubble aeration,NH3-N concentration in sewage fundamentally got the minimum in 14 h(bottom aeration needed 20 h),and its removal rate was 89%,which was 15% higher than that from the bottom aeration during the same period of time and more than 20% higher when the temperature was low.Additionally,the removal rates of TN and TP came from micro-bubble aeration were 7.5% and 6% higher than those from the bottom aeration.