Optimizing Fouling Mitigation in Membrane Distillation By Controlled Microbubble Size and Concentration

作     者：Wang, Xuelin Wang, Xitong Xu, Chenao Ye, Yubing Ning, Rongsheng Rehman, Ratul Li, Enchao Li, Pan 

作者机构：College of Environmental Science and Engineering Tongji University Shanghai200092 China State Key Laboratory of Pollution Control and Resource Reuse Shanghai Institute of Pollution Control and Ecological Security Shanghai200092 China Co. Ltd. 901 North Zhongshan Road Shanghai China Researsh Institute Baowu Water Technology Co. Ltd Shanghai China Shandong Jianzhu University China 

出 版 物：《SSRN》 

年 卷 期：2024年

核心收录：

主　　题：Mass transfer 

摘      要：Scaling control strategies play a crucial role in membrane distillation (MD) process, primarily due to the significant limitation of scaling during the scaling-up process. The utilization of microbubbles (MBs) aeration has exhibited promising potential in mitigating membrane fouling when treating high salinity wastewater. This research aims to optimizing the effect of MBs with different concentrations and sizes on membrane fouling control, we creatively used the method of releasing pressure gradiently to achieve size regulation of MBs within a certain range for the first time, firstly regulated the generation of MBs by manipulating gas flow rate and release pressure. It was observed that higher gas flow rates primarily increased MBs concentration, while lower pressures predominantly reduced MBs size through the method of inline imaging. Experimental results indicated that introduction of MBs can improve the temperature polarization coefficient and mass transfer coefficient during the treatment of NaCl solutions. Consequently, further investigations focused on the influence of MBs characteristics on different fouling control. This study provided empirical evidence that higher concentration and larger size of MBs intensify the gas-liquid two-phase flow disruption and exhibit a better shear effect on scaling phenomena, which yield advantageous outcomes in terms of augmenting permeance and water vapor production. These results were confirmed via membrane surface using scanning electron microscopy and energy dispersive spectroscopy. In summary, this research aided in identifying appropriate operating conditions for mitigating inorganic and composite scaling by implementing air-infused MBs in direct contact membrane distillation (DCMD), which provides scientific and technical guidance for controlling fouling in MD in practical applications. © 2024, The Authors. All rights reserved.