Multi-functional polyethersulfone nanofibrous membranes with ultra-high adsorption capacity and ultra-fast removal rates for dyes and bacteria

Abstract

The adsorption technology has been widely applied in water remediation for contamination removal of dyes and bacteria, by virtue of the advantages of adsorption technology including high efficiency, energy conservation and ease of operation. Simultaneous removal of dyes and bacteria has been realized by some reported materials, but to achieve satisfactory adsorption amounts and rates remain an unmet goal for decades. Herein, a poly(methacrylatoethyl trimethyl ammonium chloride-co-methyl methacrylate) copolymer was synthesized, and then blended with polyethersulfone for the fabrication of nanofibrous membranes via electrospinning for the use of fast and massive removal of dyes and bacteria. Owing to the introduction of abundant quaternary ammonium groups, the maximum adsorption amount for methyl orange was up to 909.8 mg g−1. In addition, the modified nanofibrous membranes showed good recyclability, broad applications in severe environments, selective adsorption ability, and excellent dynamic removal performance. Especially, thanks to the abundant functional groups, the membranes showed fast adsorption ability for bacteria through electrostatic interaction. It should be noted that the clearance ratio for Staphylococcus aureus or Escherichia coli by 6 min of static adsorption could reach 93 % or 90 % for each. Additionally, dynamic removal ratio via filtration with the nanofibrous membranes could reach 99.7 % for Staphylococcus aureus or 98.7 % for Escherichia coli in 90 s. Therefore, the proposed approach towards the quaternary ammonium modified polyethersulfone nanofibrous membranes creates a new route for ultra-high adsorption capacity and ultra-fast removal rates for dyes and bacteria in water remediation.