Removal of pharmaceutical compounds by chitosan nanocomposite membranes with catalytic additives from wastewater

Abstract

Pharmaceutical contaminants, such as paracetamol (PC) and ibuprofen (IB), are among the most persistent pollutants in wastewater, raising significant environmental and health concerns due to their resistance to conventional treatment methods. This study introduces four novel chitosan-based nanocomposite membranes: neat chitosan (CH), MXene/chitosan (TC), laccase-coated MXene/chitosan (LTC), and MnO₂/MXene/chitosan (MTC), developed for effective pharmaceutical contaminant removal. These membranes were thoroughly characterized using SEM to examine surface morphology, EDX for elemental composition, FTIR for chemical bonding analysis, and XRD for crystallographic structure determination. Among the membranes, LTC achieved the highest removal efficiencies, eliminating up to 99 % of IB and 93 % of PC, facilitated by the combined enzymatic degradation by laccase and catalytic properties of MXene. MTC followed closely with removal efficiencies of 98.5 % for IB and 91 % for PC, driven by a synergistic mechanism of MnO₂ and MXene, generating reactive oxygen species (ROS) to oxidize contaminants. The TC membrane exhibited moderate removal capabilities, while CH showed limited removal of <32 %. Antifouling performance was also evaluated under accelerated fouling conditions, where LTC and MTC demonstrated superior antifouling behavior with minimal flux decline and high flux recovery rates of 93 % and 95 %, respectively. These results highlight the membranes' ability to combine separation, catalytic degradation, and fouling resistance. The findings provide a sustainable, robust, and efficient solution for addressing real-world wastewater treatment challenges, particularly the removal of pharmaceutical contaminants, advancing the field of nanocomposite membrane technology.