以气升式环流反应器和膜生物反应器为基础,提出气泡循环流动型膜生物反应器的概念。利用气液循环流动减缓膜污染,通过充压渗透的操作方式,降低水处理能耗与设备投资。实验研究了下降管内中空纤维膜填充率对反应器的平均气含率、循环液速等流体力学性能的影响,使用模拟体系考察膜分离性能。研究结果表明:循环流动的气液两相能够明显缓解膜污染,提高膜渗透通量;利用充压渗透的操作方式可以实现膜分离过程,同时加压操作会导致平均气含率减小,循环液速降低。在理论分析基础上,导出平均气含率、循环液速随操作气速和压强的变化关系。
Based on the combination of the air-lift loop reactor (ALR) with the membrane bioreactor (MBR), a bubble-up loop membrane bioreactor was proposed, and its hydrodynamic behaviors were studied. A simulation system was applied to test the membrane separation performances. The gas hold-up and liquid circulation velocity were measured, and the influence of the hollow fiber membrane elements filled in the downer of the reactor on the hydrodynamic behaviors of the circulation was studied. The experimental results show that the two phase circulation can reduce the membrane fouling and increase the permeation flux simultaneously. In order to supply the driving force for membrane permeation, the bioreactor proposed can be operated under pressure, and it can reduce the energy consumption and equipment investment of the water treatment process. The experiments also show that the gas hold-up and liquid circulation velocity decrease with increasing the operating pressure. Based on theoretical analysis, a mathematical model was developed to describe the relationship of the average gas hold-up and liquid circulation velocity with the operation parameters, such as the pressure and the apparent gas velocity.