Garcinia derived adsorbents for efficient ammonium removal from wastewater in fixed bed column systems

Ammonium contamination in wastewater poses serious risks to aquatic environments and requires efficient continuous treatment strategies. This study evaluates a Garcinia-derived biosorbent for NH4+ removal in a laboratory-scale fixed-bed column and quantitatively examines the influence of flow rate, influent concentration, and bed height on dynamic adsorption behavior. Breakthrough and exhaustion were defined at Ct/Co = 0.05 and Ct/Co = 0.95, respectively. Decreasing the flow rate from 2.0 to 0.5 mL min−1 increased the Thomas capacity from 10.5 to 18.5 mg g−1 and extended breakthrough time from < 100 to ~ 240 min. Increasing bed height from 5 to 20 cm enhanced qmax from 12.0 to 23.5 mg g−1. Model validation using the Thomas and Yoon–Nelson equations showed good agreement with experimental data (R2 = 0.89–0.99, RMSE = 0.021–0.065, MAE = 0.018–0.054). The mass transfer zone (MTZ) length and empty bed contact time (EBCT) were estimated to provide additional insight into column hydrodynamics. The results demonstrate the potential applicability of Garcinia-based biosorbent for laboratory-scale continuous ammonium removal and provide useful operational insights for fixed-bed adsorption systems.