Fixed-Bed Column Performance of Poly-GMA-Glucamine for Boron Recovery in Seawater Reverse Osmosis: Breakthrough...

This study evaluates the fixed-bed column performance of poly(GMA-glucamine) for selective boron removal and recovery from natural seawater. Batch adsorption tests confirmed pseudo-second-order kinetics (R² = 0.999) with a boron uptake of 16.3 mg/g, governed by chemisorption through vicinal diol-borate complexation. Fixed-bed experiments at varying height-to-diameter ratios (5.2, 9.1, and 13.7) showed improved breakthrough performance with increased bed depth. Breakthrough data were well described by the Bohart-Adams (R² > 0.993) and Wolborska (R² = 0.957-0.989) models, indicating combined control by surface reaction and external mass transfer. BDST analysis exhibited strong linearity (R² = 0.994-0.999), with bed capacities of 3872-3999 mg/L and critical bed depths of 4.7-9.2 mm, supporting compact column design. Regeneration using 1.0 M HCl achieved 97.5% desorption efficiency and 390 mg/L boron recovery (78-fold enrichment), with over 95% capacity retained after five cycles. The resin exhibited excellent stability across salinity (30-45‰) and temperature (15-35 °C) ranges. The results provide a comprehensive techno-economic and environmental evaluation based on real operational data, offering LCA-level insight into system sustainability. Poly(GMA-glucamine) demonstrates scalable, durable, and cost-effective performance, enabling both boron recovery and sustainable seawater desalination.