Inner-selective coordination nanofiltration hollow fiber membranes from assist-pressure modified substrate

This study aims to develop an inner selective coordination nanofiltration hollow fiber (CNHF) membrane for the efficient removal of antibiotics from groundwater. In the first step, a modified substrate with the controlled modification degree is achieved by pressure-assisted alkali modification of polyimide hollow fiber substrate to provide the active points for the construction of the dense active layer. Then, the high-performance active layer is dynamically built on the modified substrate by the coordination between Fe3+ and phytic acid. Compared to static synthesis, the pure water permeability (PWP) of the membrane is improved from 4.1 to 8.5 Lm(-2)h(-1)bar(-1) and Na2SO4 rejection enhanced from 68.3% to 97.0% by the dynamic synthesis with a cross-flow system. The newly developed membranes exhibit high rejection to several pharmaceuticals (>99%). This work may provide insightful guidelines for improving the fabrication procedures and scaling up the inner-selective CNHF membrane modules for water purification and other applications.

Automated summary

This study developed an inner selective coordination nanofiltration hollow fiber membrane for efficient removal of antibiotics from groundwater. By pressure-assisted alkali modification and dynamic synthesis, the membrane showed improved performance and high rejection to various pharmaceuticals.