Adsorptive removal of Cu2+ and Ca2+ from aqueous solution by microcrystalline cellulose extracted from post-harvest banana pseudo-stem

In this study, microcrystalline cellulose was prepared from the post-harvest banana stem by using a homogeneous Fenton system (MCC-F) and used as an adsorbent for removing Cu²⁺ and Ca²⁺. Simultaneously, the reference materials of MCC-H and MCC-N were also prepared by using H₂O₂ and NaIO₄ solutions, respectively. Characteristics of the prepared materials were determined by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, the point of zero charge, and the content of aldehyde and carboxyl functional groups. In batch Cu²⁺ and Ca²⁺ adsorption tests, an optimal pH value of 7.0 was found for both target metal ions while 30 min and 75 min were chosen as the optimal contact time for Cu²⁺ and Ca²⁺ ions, respectively. The best fit was obtained with the pseudo-second-order kinetic model. Langmuir, Freundlich, and D–R isotherm models were applied to calculate adsorption data. Thermodynamic results suggest that the adsorption of metal ions by MCC-F is an exothermic and spontaneous process. Therefore, MCC-F is a high-potential and promising material for water and wastewater treatment.