Selective boron removal from seawater using poly-GMA-Glucamine

Boron removal is a persistent challenge in seawater desalination due to the limited rejection efficiency of reverse osmosis (RO) membranes at neutral pH. In this study, a boron-selective adsorbent, poly(GMA-glucamine), was synthesised via radical polymerisation of glycidyl methacrylate and functionalised with N-methyl-D-glucamine (NMDG). The incorporation of glucamine groups was confirmed by FT-IR spectroscopy and SEM analysis. Adsorption isotherms in deionised water and seawater yielded capacities of 17.38 and 16.60 mg/g, respectively. The data fitted best to the Langmuir model, suggesting monolayer adsorption, while Dubinin-Radushkevich and Temkin modelling indicated chemisorption with mean adsorption energies of ∼14 kJ/mol.This work presents an optimised poly-GMA-glucamine adsorbent with high boron selectivity and robust regeneration performance in seawater matrices. The adsorbent retained over 75% of its initial capacity after five adsorption-desorption cycles.These results demonstrate that poly-GMA-glucamine is a high-capacity, salt-tolerant, and reusable material suitable for boron removal from RO permeates. Its performance characteristics support its applicability in seawater desalination systems, where achieving compliance with drinking water standards remains a critical requirement.