Removal of phthalate esters by integrated adsorption and biodegradation using improved performance of lipase@MOFs

Phthalate esters (PAEs) are broadly utilized as plasticizers in industrial products, posing a significant threat to ecological security and human health. Lipase is a kind of green biocatalyst with the ability to degrade PAEs, but its application is limited due to its low stability and poor reusability. Herein, lipase from Candida rugosa (CRL) was immobilized into an organic ligand replacement MOFs (MAF-507) and cysteine modification and glutaraldehyde cross-linking were simultaneously performed to synthesize immobilized lipase (Cys-CRL@GA@MAF-507) using a one-pot method. Compared with free CRL, Cys-CRL@GA@MAF-507 not only increased its relative activity to 1.66-fold as well as improved its thermostability to 247% at 30 °C, but also constructed a synergistic system of combined adsorption and biodegradation to remove PAEs. In actual water environment, Cys-CRL@GA@MAF-507 could adsorb 88.56% of dibutyl phthalate (DBP) within 5 min and degrade 94.6% of DBP within 48 h, respectively. Therefore, this research developed an innovative bifunctional enzyme@MOFs biocomposite with synergistic adsorption and biodegradation for the efficient removal of PAEs, which provides a new platform for the elimination of pollutants in environmental remediation and industrial application.