Asymmetric polyethersulfone ultrafiltration membranes with high perm-selectivity of nitrate ions for energy-efficient water treatment
This study presents the fabrication and evaluation of asymmetric
polyethersulfone (PES) ultrafiltration membranes designed for high
perm-selectivity of nitrate ions from mixed-ion solutions.
Polyvinylpyrrolidone (PVP) was employed as a pore-forming agent to
modify the porous structure of the membranes, particularly affecting the
characteristics of the surface skin layer. These structural
modifications play a crucial role in determining the physical properties
and water permeation flux of the designer membranes. Additionally, the
membrane comprising 16 wt% PES and 5 wt% PVP exhibits superior
performance in the selective separation of nitrate (NO3–) ions from fluoride (F−) and sulfate (SO42−) ions during electrolysis. At a constant potential of 1 V, the P16K5 membrane delivers a perm-selectivity of 1.6 and 2.6 for NO3–/F− and NO3–/SO42−, respectively. Additionally, nearly 100 % of NO3– removal can be achieved at an applied potential of 5 V. Furthermore,
the energy consumption analysis suggests that the proposed asymmetric
PES membrane serves as a promising ion-selective material for
energy-efficient water treatment applications in a cost-effective
manner.
