# Synergistic Effect of NiFe-LDH and PES/SPSf Matrix on Metal Ion Rejection Efficiency from Surface Water

## TL;DR

This study creates a new membrane combining PES/SPSf and NiFe-LDH to efficiently remove heavy metals and proteins from water.

## Contribution

A novel membrane with enhanced metal ion rejection and antifouling properties through a synergistic polymer-LDH combination.

## Key findings

- The M3 membrane achieved a pure water flux of 218 L.m−2h−1, three times higher than the base membrane.
- M3 removed 92.4% of BSA and over 90% of Cd2+, Pb2+, and Cu2+ from water.
- The membrane maintained over 65.9% flux recovery after three fouling–cleaning cycles.

## Abstract

Clean water remains a pressing global challenge and developing membranes that are both efficient and durable is critical. This study combined two polymers, polyethersulfone (PES) and sulfone-modified polysulfone (SPSf), with NiFe-layered double hydroxides (LDHs) to create a new class of multifunctional membranes. The membranes were characterized using FTIR, SEM, water contact angle, and zeta potential. The addition of NiFe-LDH fillers improved the hydrophilicity and surface structure of the membranes and enhanced the separation performance of the resulting membranes. The best-performing membrane (M3, with 2 wt.% NiFe-LDH) delivered pure water flux of about 218 L.m−2h−1, which was nearly three times higher than that of the pristine PES/SPSf membrane. Furthermore, M3 removed approximately 92.4% of bovine serum albumin (BSA), attributed to the synergistic combination of size exclusion, electrostatic repulsion, and hydrophilicity. The membrane also showed excellent antifouling properties, maintaining over 65.9% and 71.2% flux recovery after three fouling–cleaning cycles for BSA solution and surface water, respectively. Importantly, the M3 membrane achieved high removal efficiencies for heavy metals, rejecting 91% of Cd2+, 93% of Pb2+, and 88% of Cu2+. These results highlight how the synergy between PES/SPSf and NiFe-LDH can overcome the common challenges of fouling and low metal ion rejection, offering a promising route toward practical and sustainable water treatment solutions.