Synthesis, Characterization and Fixed-Bed Fluoride Adsorption Performance of a Banana Pseudostem Cellulose–Montmorillonite Composite

Excessive fluoride in drinking water poses significant public-health concerns, particularly in communities that depend on untreated groundwater. This study synthesized a banana pseudostem cellulose–montmorillonite composite and evaluated its performance for fluoride removal in a continuous fixed-bed adsorption column. Cellulose was extracted from banana pseudostem and combined with montmorillonite by aqueous blending with citric-acid-assisted preparation. The composite was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier-transform infrared spectroscopy and Brunauer–Emmett–Teller surface-area analysis. The reported specific surface area increased from 2.0 m²/g for untreated cellulose to 16.5 m²/g for the composite. Fixed-bed experiments examined the effects of adsorbent mass, contact time, flow rate and influent fluoride concentration. The maximum reported removal efficiency was 79.83% at an adsorbent mass of 10 g. Removal efficiency decreased from 76.36% to 55.42% over five reuse cycles. Treatment of borehole water from five communities in Gombe State gave removal efficiencies of 61.69% to 76.36%. Reported column-model coefficients could not be independently validated because the raw breakthrough data and model-specific conditions were unavailable. The findings suggest that the composite has potential for fluoride adsorption. However, mass-balance analysis, experimental replication, leaching assessment and verification of treated-water quality are necessary before practical application.