Utilization of treated coffee waste as adsorbent for heavy metal (Cadmium, Chromium and Lead) removal from synthetic water

In this study, treated coffee waste was used to remove heavy metals (Cd, Cr and Pb) from synthetic water. For the adsorption studies, operational parameter such as adsorbent dosage and contact time were studied. For the characterization, Fourier-transform infrared spectroscopy (FT-IR) and Scanning electron microscope (SEM) were used to identify functional group and observed the surface of treated coffee waste. Removal heavy metals were studied using 100 ml of synthetic waste contained 7.5 ppm (Pb), 4.8 ppm (Cr) and 0.9 ppm (Cd) in room temperature. All adsorption processes were carried out for different dosage and contact time to identify the optimum condition for adsorption. Concentrations of synthetic water were measured using atomic adsorption spectroscopy (AAS). The results were analyzed using percentage removal heavy metals and adsorption capacity. The higher percentage removal heavy metals for 0.5g of adsorbent were 74.4 % (Pb), 50% (Cr) and 44% (Cd) respectively. For 0.7 g, the percentage removal were Pb (84%) followed by Cd (35%) and Cr (30%). For 1 g and 3 g, the percentage removal were Pb (85%), Cd (40%), Cr (-33%) and 75.5 %( Pb), 50.5 % (Cd) and 20% (Cr) Every dosage was observed with different contact. The best contact time for 0.5 g, 0.7 g, 1 g, and 3 g of dosage was 1 hour to reach equilibrium state. In conclusion, this study indicates that treated coffee waste could be employed as a potential adsorbent for heavy metals removal from synthetic water and could be better than untreated coffee waste.