Adsorption of Cu (II) Ions from Aqueous Solution onto Chemically Prepared Activated Carbon from Theobroma cacoa

This present research was aimed at studying the adsorption characteristics of Cu(II) ions from aqueous solutions onto two samples of low-cost, cocoa shell-based activated carbons (CSBAC) using the batch adsorption mode. Activated carbon samples were obtained by chemical treatment via pyrolysis using phosphoric acid (PAA) and potassium hydroxide (PHA) as activation agent. Findings from the studies unveiled a pH at zero-point charge (pHzpc) of 7.0 and 5.9 for PAA and PHA samples respectively. Contact time of 35 minutes for PAA and 15 minutes for PHA at pHmax = 4 by 0.1 g were observed. Optimum adsorption quantities were 62.2 mg/g for PAA and 42.2 mg/g for PHA for an initial metal ion concentration of 2400 ppm. The Langmuir model for PHA and Freundlich model for PAA best described the adsorption of Cu (II) ions from aqueous solution. The two CSBAC samples both obeyed pseudo-second order kinetics. Generally, these results indicate that CSBAC can be used as an effective and low-cost adsorbent for the removal of Cu (II) ions from aqueous solutions.