Preparation of C=C polymerization-oriented magnetic protein molecularly imprinted polymer and the application for membrane flux improvement

Abstract

This study aims to prepare a novel C=C polymerization-oriented magnetic protein molecularly imprinted polymer (MMIP) to improve membrane flux by adsorbing protein-type membrane foulants. The adsorption capabilities of MMIP were assessed by batch experiments, and the oriented polymerization and adsorption mechanisms were further revealed by density functional theory (DFT). The findings suggested that the MMIP exhibited a favorable adsorption capacity (35.9 mg/g) and high specificity (imprinting factor, IF = 2.2) to bovine serum albumin (BSA), and showed an impressive adsorption capacity (21.2 mg/g) to protein-type substances in soluble microbial products (SMPs) derived from a functioning membrane bioreactor. Consequently, the MMIP reduced the filtration resistance by approximately 91.6 % compared to the control group and improved the membrane flux. Moreover, the data confirmed that the adsorption was a monolayer adsorption process in which chemical interactions dominated the rate-limiting step. DFT calculations proved that the functional monomer chain reactions predominantly occurred on C=C bonds in the oriented polymerization and the hydrogen bonding was identified as the main interaction between MMIP and protein in the adsorption. These findings suggested that the MMIP holds great potential as a recyclable adsorbent for effectively improving membrane flux through the selective adsorption of protein-type membrane foulants.