Nano-engineered Rice Husk-Derived Thin Film Nanocomposite Membranes for Arsenic Removal: Mechanistic Insights and Functional Performance

A persistent environmental and public health concern in the Mekong River Basin is arsenic contamination of groundwater, particularly in rural Cambodia, where decentralised water treatment technologies are. This study aims to develop high-performance thin-film nanocomposite (TFN) membranes incorporating functionalised silica nanoparticles derived from rice husk agricultural by-products as a sustainable and scalable solution for arsenic remediation. Their arsenic affinity and interfacial compatibility is enhanced by surface-functionalisation with either -NH2 or -OH groups. Interfacial polymerisation of an m-phenylenediamine (MPD) aqueous phase and trimesoyl chloride (TMC) organic phase, incorporates these nanoparticles into the polyamide selective layer at a loading of 0.05–0.5 wt% in accordance with established TFN membrane fabrication protocols. Membrane performance will be evaluated under both simulated groundwater conditions containing arsenite (As(III)) and arsenate (As(V)). At low pressure operation, we are targeting an arsenic rejection of more than 95% and a pure water flux of 12–15 L/m2h, antifouling behaviour, and long-term operation stability. The structure-property relationships and adsorption-rejection mechanisms will be investigated using advanced characterisation techniques (SEM, TEM, FTIR, XPS, and contact angle analysis). This work aligns with circular economy principles while reducing material costs and environmental impact. Compared to conventional thin-film composite membranes the proposed TFN membranes are expected to exhibit improved permeability-selectivity trade-offs. Decentralised water treatment systems can be implemented at a pilot scale in resource-constrained settings through the findings of the study, which will contribute to membrane science literature.