Plasma-Assisted Immobilization of Laccase on Polyethylene/Polypropylene Nonwoven Substrates and Its Performance Evaluation in Dye Decolorization

Abstract

In this study, a polyethylene/polypropylene (PEPP) nonwoven material was developed as a support for laccase immobilization through a low-temperature ammonia plasma pretreatment technique. For this purpose, the optimal glutaraldehyde (GA) cross-linking conditions and laccase immobilization parameters for ammonia plasma-treated PEPP nonwoven were systematically optimized, and the stability of the treated PEPP nonwoven was evaluated under these optimal conditions. Furthermore, the potential applicability of PEPP nonwoven in wastewater treatment was assessed by examining its decolorization efficiency in solutions containing two synthetic dyes, C.I. Acid Blue 74 and C.I. Acid Blue 62. X-ray photoelectron spectroscopy (XPS) analysis confirmed an increase in the N 1s atomic composition of the PEPP nonwoven fabric from 6.54% to 12.72% after ammonia plasma treatment. The optimal conditions for laccase immobilization on PEPP nonwoven were found to be pH 6.0, 4 degrees C, 600 min, and 35% (owf) laccase. The immobilized laccase exhibited improved pH, thermal, and storage stability compared to free laccase, retaining 40% of its initial activity after 10 reuse cycles. Finally, the decolorization efficiencies of the immobilized laccase on PEPP nonwoven for C.I. Acid Blue 74 and C.I. Acid Blue 62 were 85% and 42%, respectively.