Adsorption Characteristics of Copper using Biochar Derived from Exhausted Coffee Residue

Abstract

BACKGROUND:There is very limited knowledge of the effects of biochar derived from exhausted coffee residue on metal adsorption processes.Furthermore, only limited information is available on the adsorption mechanism of copper.The aim of this study was to evaluate the absorption behaviors of copper by biochar derived from exhausted coffee residue.METHODS AND RESULTS: Biochars produced by pyrolysis of exhausted coffee residue at 300 (CB300) and ℃ 600 (CB600) were characterized and investigated as ℃ adsorbents for the removal of copper from aqueous solution.The results indicated that the adsorption equilibrium was achieved around 2 h and the pseudo-second-order kinetic model fit the data better than the pseudo-first-order kinetic model.The maximum Cu adsorption capacities of CB600 by Freundlich and Langmuir isotherms were higher than those of CB300.The adsorption data were well described by a Langmuir isotherm compare to Freundlich isotherm.CONCLUSION: Our results suggest that exhausted coffee residue can be used as feedstock materials to produce high quality biochar, which could be used as adsorbents to removal copper.