Zirconium-pillared montmorillonite as a thermally regenerable adsorbent for microbial removal

This study evaluates zirconium-pillared montmorillonite (Na-Zr 2.5) as a reusable adsorbent for the removal of microorganisms from aqueous systems under conditions relevant to wastewater treatment, including the effect of temperature and performance in both monoculture and mixed bacterial suspensions. Removal efficiencies of approximately 60-70% were achieved for both Gram-negative and Gram-positive bacteria, indicating non-selective adsorption independent of cell wall structure. In mixed bacterial systems, removal efficiencies of approximately 60% were achieved, while higher efficiencies (>80%) were observed in natural water matrices, demonstrating applicability under complex conditions. Thermal regeneration enabled repeated reuse, with stable performance maintained over multiple adsorption–regeneration cycles under the investigated conditions. FTIR, XRD, SEM and ICP analyses showed preservation of structural features after regeneration, while DLS and zeta potential measurements suggest that surface charge differences contribute to the adsorption process. Overall, Na-Zr 2.5 shows strong potential as a robust and reusable adsorbent for microbial removal in wastewater treatment applications.