Adsorption performance of Pb(II) ions from aqueous solution onto a novel complex of coffee grounds and attapulgite clay

Abstract

As one kind of easily available, low cost and long-duration method, the adsorption method procedure has already been applied widely in water treatment for recent years. In this paper, synthesized complex of coffee grounds and attapulgite clay (CG/AC) was designed through hydrothermal reaction and employed for removal of toxic Pb(II) ions. The adsorbent of designed CG/AC was characterized by means of FTIR, XRD and SEM. The results were indicating that CG was loaded well with AC through preparation by combination of hydrothermal synthesis. The Pb(II) adsorption kinetic was well fitted by second order model from the adsorption kinetic experiments. The adsorption reaction reached equilibrium within 60 min and the maximum adsorption capacity was 4.45 mg·g–1at 25°C. The adsorption isotherm for Pb(II) was better fitted by Langmuir isotherm model. The higher temperature would be beneficial to adsorption of Pb(II) by designed CG/AC and the maximum adsorption capacity could reach up to 6.98 mg·g–1 at 35°C. Thus, CG/AC showed relatively great potential for adsorption capacity of Pb(II) in aqueous solution, which should shed light on its application in wastewater treatment.