Enzymatic removal of paracetamol from aqueous phase: horseradish peroxidase immobilized on nanofibrous membranes

Paracetamol is a widely used as an analgesic and an antipyretic that can easily accumulate in aquatic environments. This study aimed to enhance paracetamol removal efficiency from water by combining the biocatalytic activity of horseradish peroxidase (HRP) with the adsorption of nanofibrous membrane. Poly(vinyl alcohol)/poly(acrylic acid)/SiO2 electrospinning nanofibrous membrane was prepared with fiber diameters of 200 to 300 nm. The membrane was made insoluble by the thermal cross-linking process. HRP, which was previously activated by 1,1'-carbonyldiimidazole, was covalently immobilized on the surface of nanofibers. Immobilized HRP retained 79.4 % of the activity of free HRP. The physical, chemical, and biochemical properties of the immobilized HRP and its application in paracetamol removal were comprehensively investigated. Immobilized HRP showed better storage capability and higher tolerance to the changes in pH and temperature than free HRP. Paracetamol removal rate by immobilized HRP (83.5 %) was similar to that of free HRP (84.4 %), but immobilized HRP showed excellent reusability. The results signify that enzyme immobilized on nanofibers has great application potential in water treatment.