Abstract:

The low energy consumption and efficient treatment of oily wastewater using microbubble flotation technology is a current research hotspot. A low-energy microbubble jet flotation system for treating oily wastewater was established using an effervescent atomizer as a microbubble generator. The effects of air-liquid mass flow ratio(ALR) and working pressure (p) on the size distribution characteristics of microbubbles and de-oiling capacity were discussed, and the energy consumption of effervescent atomizer was analyzed. The experimental results showed that a large number of microbubbles could be generated by using the effervescent atomizer to organize submerged jet, the number of microbubbles with diameters less than 150 μm accounted for more than 55%, and the number of microbubbles with diameters less than 600 μm accounted for more than 98%. The number of microbubbles increased first and then decreased with the increase of ALR, and the optimum ALR was 0.15. When p was 0.2 MPa and ALR was 0.15, the Sauter mean diameter of microbubbles could be as low as 238 μm, the oil concentration in wastewater was 29.73 mg/L, the power consumed by the microbubble jet flotation was only 6.53×10^-4 kW·h per kilogram of wastewater, which was more than 35% lower than dissolved air flotation.

Key words: low energy consumption, microbubble, jet floatation, oily wastewater, effervescent atomizer

摘要：

微气泡气浮技术在低能耗下对含油污水的高效处理是目前的研究热点。利用气泡雾化喷嘴作为微气泡发生器，搭建了低能耗微气泡射流气浮处理含油污水的实验系统，系统研究了气液质量流量比（ALR）和工作压力（p）对微气泡群尺度分布特征和除油效果的影响，并计算了气泡雾化喷嘴的能耗。实验结果表明，利用气泡雾化喷嘴形成液下射流可以产生大量微气泡，其中尺度小于150 μm的气泡数量占比在55%以上、小于600 μm的气泡数量占比在98%以上；随着ALR的增加，微气泡数量整体呈现先增后减的变化趋势，最佳ALR=0.15；当p=0.2 MPa、ALR=0.15时，微气泡群的索特尔平均直径可降低至238 μm，出水含油质量浓度为29.73 mg/L，微气泡射流气浮装置处理1 kg含油污水时能耗仅为6.53×10^-4 kW·h，较溶气气浮能耗降低35%以上。

关键词: 低能耗, 微气泡, 射流气浮法, 含油污水, 气泡雾化喷嘴

CLC Number: 

• X703