Nanosurface-immobilized lipase and its degradation of phthalate wastewater

Abstract

Phthalic acid esters (PAEs) are hard-to-degrade organic pollutants of current concern, and enzyme degradation is a green method for effective degradation of PAEs. To improve the recognition of PAEs, the combination of molecular blotting and immobilized enzyme technology is a novel and efficient method for the degradation of PAEs. In this study, molecularly imprinted carrier (MIP-HNTs) was prepared from halloysite nanotubes (HNTs), using di(2-ethylhexyl) phthalate (DEHP) as the template molecule, methyl methacrylate (MMA) as the functional monomer and (ethylene methacrylate) EDGMA as the cross-linking agent. A novel immobilized enzyme (MIP-HNTs@lipase) was prepared successfully via glutaraldehyde cross-linking, subsequently. The lipase loading efficiency was 76%. The optimal enzymatic activity conditions for MIP-HNTs@lipase were determined to be pH=9 and 50 °C. The MIP-HNTs@lipase exhibited good stability and efficient degradation of DEHP with a degradation rate of 94.758% when the DEHP concentration was at 5 mg·L–1. This research provided a new strategy for industrial application of enzymes and degradation of persistent pollutants.