Supramolecular enzymatic membranes comprising of β-cyclodextrin and laccase for efficient removal and desalination of small molecules

Abstract

Nanofiltration (NF) is regarded as a great potential technique for efficient treatment of industrial dyes and pharmaceutical effluents, however, its application still faces the challenges due to the trade-off among permeance, selectivity and anti-fouling property. Herein, a novel supramolecular enzymatic membrane was designed and successfully fabricated based on β-cyclodextrin (CD) and laccase (Lac), with the former providing supramolecular transport channels and the latter offering the pollutant degradation property. Specifically, after the host-guest complexation of CD with polyethylene glycol (PEG), the generated CD@PEG supramolecules were introduced into interfacial polymerization (IP) via reacting with terephthaloyl chloride (TPC) to fabricate supramolecular membrane with “bead-like” channels. Furthermore, the laccase was immobilized onto the modified polysulfone (mPSf) surface to generate CD@PEG@Lac-TPC/mPSf supramolecular enzymatic membrane for high-efficiency catalytic degradation of membrane foulants. The CD@PEG-TPC/mPSf supramolecular membrane displayed excellent performance and operation stability for removal and desalination of small molecules, with pure water permeance up to 26.8 L·m−2·h−1·bar−1, and satisfactory NaCl/dye and NaCl/medicine separation factors. Moreover, CD@PEG@Lac-TPC/mPSf supramolecular enzymatic membrane showed an effective anti-fouling property with only 8.0 % permeance decline rate after 24 h continuous separation of tetracycline hydrochloride solution, suggesting its potential application for removal and desalination of small molecules.