INVESTIGATION OF ADSORPTION PERFORMANCE OF CALCIUM CARBONATE MICROPARTICLES PREPARED FROM EGGSHELLS WASTE

The research aimed to evaluate the adsorption of curcumin by determining the isotherm adsorption characteristics of calcium carbonate particles made from eggshells. Standard isotherm models were used to evaluate the adsorption isotherm i.e., Hill-de Boer, Dubinin Radushkevich, Temkin, and Fowler-Guggenheim models. Calcium carbonate was prepared through cleaning, drying, grinding, and carbonizing of eggshells. The adsorption isotherm was conducted using the batch method using curcumin adsorbate under constant pressure and pH. The results showed that the adsorption process was appropriate respectively to Temkin > Dubinin-Radushkevich > Fowler Guggenheim > Hill-de Boer. The results adsorption process showed that 500-mu m sized calcium carbonate have physical adsorption on a multilayer surface with a uniform distribution of binding energies followed by the carbon surface no micropores, so the adsorbed molecules interacted by repulsive force. Endothermic methods are used to carry out adsorption at various sites. The determined Gibbs free energy for all models is positive, indicating that the adsorption mechanism is unspontaneous. This study demonstrates the useful process for producing calcium carbonate from households namely eggshells, giving a good alternative for further expected to assist the process of wastewater treatment development of carbon material from green chemistry.