通气量对微孔曝气器充氧性能影响的中试研究

Impact of Airflow Rate on Oxygen Mass Transfer in a Pilot-scale Fine Bubble Aeration System

通过中试评价了不同通气量对微孔曝气器充氧性能的影响。结果显示,当单位曝气面积通气量从58.976 m3/(m2·h)增加到235.905 m3/(m2·h)时,阻力损失RL从3.35 kPa(0.335 m)突增到26.5 kPa(2.650 m),在研究的气量范围内二者呈平方关系;标准氧总转移系数KLas从0.025 min-1增加到0.083 min-1,充氧能力qc从0.145 kgO2/h增加到0.483 kgO2/h,在研究的气量范围内两个指标都与通气量呈线性关系;氧利用率ε则从27.7%降低到21.5%,理论动力效率E从6.205 kgO2/(kW·h)降低到4.027 kgO2/(kW·h),在研究的气量范围内ε和E两个指标都与通气量呈近似幂函数关系。由于通气量对充氧性能有较大的影响,合理控制通气量对于提高曝气性能、降低曝气系统能耗具有重要意义。

The impact of airflow rate （AR） on oxygen mass transfer in a pilot-scale fine bubble aeration system was evaluated. The results showed that when the AR per unit area increased from 58. 976 to 235. 905 m3/（m2 · h）, the resistance loss （RL） increased sharply from 3.35 （0. 335 m） to 26.5 kPa （2. 650 m） , the standard oxygen transfer coefficient （ KLas） increased from 0. 025 to 0. 083 min-1, and the oxygen transfer rate （qc） increased from 0. 145 to 0. 483 kgO2/h, indicating a quadratic relationship between RL and AR and a nearly linear relationship between KLas and AR, qo and AR. However, the theoretical power efficiency （E） decreased from 6. 205 to 4. 027 kgO2/（kW · h）, and the oxygen transfer efficiency （ε） decreased from 27.7% to 21.5% , suggesting a power function between E and AR, ε and AR. Thus, airflow control is helpful for reducing energy consumption and improving oxygen mass transfer in fine bubble wastewater treatment system.