Magnetic nanocomposite synthesized from cocopeat for highly efficient mercury removal from aqueous solutions

The utilization of renewable and cost-effective biomass for the production of activated carbon represents an innovative approach to environmental remediation. In this work, environmentally friendly carbon materials derived from cocopeat were employed to create a cocopeat-based magnetic activated carbon (CPAC-Fe₃O₄) nanocomposite for the removal of mercury from aqueous solutions. The CPAC-Fe₃O₄ nanocomposite underwent comprehensive characterization using SEM, FTIR, BET, XRD, and VSM analyses. The optimization process revealed a maximum adsorption capacity of 204.08 mg/g under specific conditions: initial Hg concentration of 20 mg/L, pH of 6, temperature of 25 °C, and adsorbent dose of 0.01 g within 60 min. Isotherm and kinetic modeling exhibited strong agreement with the Freundlich isotherm (0.9749) and pseudo-second-order (0.9997) kinetic models, indicating a favorable chemisorption process. Furthermore, thermodynamic analysis suggested that the adsorption process is endothermic and spontaneous. The adsorption mechanism was elucidated based on FTIR analysis. The results highlight the CPAC-Fe₃O₄ nanocomposite as a promising and sustainable candidate for effective water purification.