In response to the need for cost-effective and eco-friendly materials in water purification, this study investigates the adsorption behavior of Co(II) ions from aqueous solutions using activated carbon derived from Posidonia oceanica, a sustainable and underutilized marine biomass. The adsorbent was prepared via high-temperature physical activation and characterized by FTIR, SEM, and BET analyses, confirming its porous structure and surface functionalities. Effects of pH, temperature, initial concentration, dosage, particle size, and contact time were studied. Under optimal conditions (pH 6.00, 293.15 K, 400 mg L–1, 0.05 g/10 mL), Co(II) removal reached 96.6%. Kinetics followed the pseudo-second-order model, indicating chemisorption, while intraparticle diffusion contributed without being the sole rate-limiting step. Equilibrium data fitted the Langmuir isotherm with a maximum capacity of 116.28 mg g–1 at 20°C. Thermodynamic analysis confirmed a spontaneous and exothermic process. Unlike previous studies with broader metal scope, this work provides in-depth insight into Co(II) removal mechanisms, underscoring the strong potential of P. oceanica-based activated carbon for scalable heavy metal remediation applications.
Erden et al. (Wed,) studied this question.