Adsorption kinetics and capacity of activated carbon derived from non-woody waste biomass for water remediation

In this study, the adsorption potential of eight different activated carbons derived from coffee waste and empty fruit bunches was investigated using three different activating agents in order to remove two pollutants, methylene blue and phenol, from aqueous solutions. Adsorption capacity was evaluated at varying adsorbent concentrations, ranging from 500–1500 mg/L, and kinetic models of pseudo 1st and 2nd order was interpreted to determine the best fit model. The findings indicated that the pseudo 2nd order model was a good fit for both pollutants, with R² values of 0.99. For phenol and methylene blue, the highest adsorption capacities of the adsorbent were found to be 1021.14 and 85.2 mg/g, respectively. Activated carbon prepared with KOH was found to be highly effective in removing almost 100% of phenol and methylene blue. Overall, these findings suggest that activated carbon obtained from agricultural byproducts can serve as a potential low-cost adsorbent to remove organic pollutants from aqueous solutions.