Study on the separation efficiency of hydrophilic PAES-COOH ultrafiltration membrane enhanced by micro-nano bubbles in low temperature environment

In light of the challenges posed by heightened water viscosity and aggravated membrane fouling at low temperatures, this study proposes a novel approach to enhance ultrafiltration (UF) performance. By integrating micro/nano bubbles (MNBs) with UF membrane modification, we aim to mitigate the adverse effects of increased viscosity of feed solution and reduce membrane fouling at low temperatures. Specifically, the utilization of carboxyl-modified poly (aryl ether sulfone) UF membranes enhances water flux and fouling resistance. Our findings indicate that the coupled system maintains comparable flux at both low (5 ± 1 °C) and room (22 ± 1 °C) temperatures, indicating excellent UF permeate performance under low temperatures. Notably, when applied to the cyclic filtration of secondary effluent during winter, the permeate flux of the proposed system surpasses that of the commercial PES UF membrane system by 184.82 %. After three filtration cycles, the permeate flux remains 233.19 % higher than that of the commercial PES UF membrane system, with flux recovery rates ( F RR ) exceeding 90 % in each cycle. These results demonstrate the efficacy of our strategy in addressing the challenges of low-temperature UF, achieving efficient separation processes. Our coupled system represents a promising advancement, offering novel insights and practical solutions for membrane-based water treatment in low-temperature environments.