Comparison of adsorbing on dissolved copper metal by Natural and Activated Carbon from Rambutan (Nephelium Sp.) Rods

Abstract

There are two adsorbents used in this research. The first one is natural carbon from rambutan rods and the other is the carbon rambutan rods that were synthesized and used nitric acid as a modifying agent. The performance of the modified carbon rambutan rods (MCRR) and natural carbon rambutan rods (NCRR) was characterized by SEM-EDX, FTIR, and AAS. Cu (II) adsorption from aqueous solutions with MCRR and NCRR was studied at varying adsorbent doses, initial Cu (II) concentration, and stirring speed. The batch equilibrium data fitted well to the Langmuir isotherm. The maximum adsorption capacity of MCRR and NCRR for Cu (II) was 5.504 mg/g (100/200 mesh, 70 ppm, 150 rpm) and 3.347 mg/g (100/200 mesh, 70 ppm, 150 rpm). MCRR was relatively large compared to NCRR as reported. Kinetic data were best fitted with the pseudo-second-order kinetic model. The intra-particle diffusion model was applied to investigate the adsorption mechanisms. The obtained thermodynamic parameters showed that Cu (II) adsorption onto the adsorbent was a chemical interaction process. These results showed that the carbon from modified rambutan rods could be considered as a potential adsorbent for the removal of Cu (II) ions from aqueous solutions than NCRR.