Biosorption of Lead by Spent Coffee Ground: Kinetic and Isotherm Studies

In coffee producing countries, the large quantities of coffee waste constitute a source of environmental pollution. The potential use of spent coffee ground (SCG) for the removal of Pb (II) from aqueous solution has been investigated as a potential low-cost treatment method for heavy metal adsorption. Batch experiments were used to examine kinetics and adsorption isotherm. The heavy metal adsorption capacity of the adsorbent was studied as a function of contact time, adsorbate concentration and stirring speed. Different adsorption model equations for isotherm and kinetics adsorption were used to find out the best model, which fit well to the experimental data. The determination  of mass transfer coefficients are a fundamental part of the escalation of the adsorption systems to industrial levels, and the analysis was realized through Weber & Morris model, and Crank model. The results show that the SCG could be considered as a potential adsorbent for lead removal from aqueous solutions.