Novel application of biochar in aramid nanofiltration membrane for enhanced antifouling performance

This study introduces a scalable strategy for tailoring Kevlar nanofiltration membranes using biochar produced at controlled pyrolysis temperatures. Biochar was incorporated into the membrane via a thermal-assisted phase inversion method to enhance permeability and antifouling performance. Structural characterisation was conducted using SEM, BET, FTIR, XPS, and water contact angle measurements, while antifouling behaviour was assessed through flux decay and flux recovery tests using BSA as a model foulant. Membranes modified with low-pyrolysis temperature biochar achieved an 87% increase in water flux while maintaining high and excellent fouling reversibility (FRR = 89%). In contrast, high-pyrolysis-temperature biochar yielded a larger flux enhancement (209%) and a higher fouling resistance (FRR = 81%). Regression analysis (R² > 0.90) revealed strong, systematic correlations between biochar loading and improvements in porosity, hydrophilicity, and permeability. Overall, the results demonstrate that biochar serves as a low-cost, tunable, and sustainable modifier, enabling the engineering of high-performance Kevlar nanofiltration membranes that are well-suited for treating wastewater streams.