Multifunctional Electrospun Polyacrylonitrile/Polyaniline/Cellulose Nanocrystal/Reduced Graphene Oxide Membranes Enable Bacterial Inactivation and Lead Removal for Decentralized Water Treatment

In developing countries and rural areas, access to safe drinking water is a pressing issue that necessitates portable treatment solutions. This study describes the development of a portable conductive membrane capable of filtering and inactivating waterborne pathogens, removing lead (Pb (II)), and improving water quality parameters using a low-voltage current. A membrane composed of polyacrylonitrile (PAN) and polyaniline (PANI) integrated with cellulose nanocrystals (CNC) and graphene oxide (GO) nanosheets (PAN@PANI/CNC/GO) was first optimized to determine the optimal GO concentration. The incorporation of these nanomaterials improved the wettability, increased hydraulic conductivity, and enhanced mechanical properties. The PAN@PANI/CNC/GO membrane with 0.5% GO was subsequently reduced using the eco-friendly l-(+)-ascorbic acid (LAA) method, resulting in a PAN@PANI/CNC/rGO membrane with enhanced conductivity. The reduced PAN@PANI/CNC/rGO exhibited an electrical conductivity of 1.83 ± 0.01 S/cm, enabling an efficient electrochemical performance at low voltages. At a voltage of 3 V, the membrane achieved a 7-log reduction of Escherichia coli and Bacillus subtilis. In addition, it effectively reduced nitrate, phosphate, and turbidity concentrations and removed 76% of Pb (II) from real water samples spiked with 0.1 mg/L of Pb (II), confirming its multifunctional removal capability. These results highlight the PAN@PANI/CNC/rGO membrane as a promising point-of-use (POU) nanocomposite material for integrated bacterial inactivation, heavy metal removal, and overall improvement in water quality.