Investigation of the use of coffee bean wastes as adsorbent

In this thesis, the adsorption potentials of natural and modified coffee wastes from their aqueous solutions of Pb (II), Cu (II), and Ni (II) ions were investigated. Coffee wastes obtained from Arabica type coffee beans were used in the experiments. Natural coffee waste has been modified with polyvinyl alcohol (PVA). Characterization processes of natural and modified coffee wastes were carried out using various spectroscopic and thermal analysis methods (XRD, SEM-EDX, FT-IR, BET and TGA). Then, the effects of adsorbent amount, pH, contact time, initial solution concentration and temperature on the adsorption of heavy metal ions were investigated. Kinetic, isotherm and thermodynamic parameters were calculated to elucidate the adsorption mechanism. Adsorption-desorption cycle experiments were also carried out to investigate the reusability of adsorbents. As a result, it has been observed that modified coffee wastes are an effective adsorbent for the removal of heavy metal ions from aqueous solutions and their reuse performance is high.