Covalent laccase immobilization on the surface of poly(vinylidene fluoride) polymer membrane for enhanced biocatalytic removal of dyes pollutants from aqueous environment

Biocatalytic removal with laccase immobilized on diverse membranes offers an attractive option to search alternative to traditional wastewater treatment processes for the removal of high toxic azo dye. In this work, the modified poly(vinylidene fluoride) membrane (PVDF) with chemical stability and high mechanical strength was developed for laccase immobilization via covalent bonding. The key design for the synthesis of biocatalytic membrane is the construction of hybrid bio-inorganic structure on the surface of polydopamine (PDA)-coated PVDF ( [email protected] ). In this respect, the PDA layer was used as a secondary platform for the grafting of 3-triethoxysilylpropylamine (APTES) modified Fe 2 O 3 @SiO 2 cubes ( [email protected] ) via a solvothermal process, resulting in the formation of [email protected] @PVDF membrane. Subsequently, laccase was immobilized on the surface of [email protected] [email protected] via gluteraldehyde (GA) crosslinking ( [email protected] [email protected] ). The removal efficiency of congo red by [email protected] @PVDF reached 97.1 % under optimal reaction conditions (pH 7.0 and temperature 35 ℃), which was more efficient than free laccase. Moreover, the as-prepared [email protected] @PVDF not only exhibited an excellent stability after low temperature storage, but also showed an outstanding reusability. Therefore, we believe that this work opens up a potential strategy for removal of other water pollutants, and provide a simple and convenient way for large-scale applications of enzyme-catalysis.