Modified low cost adsorbent (cedar) for the removal of Pb (II), Ni (II) and Zn (II) from aqueous solutions

摘要

Increased industrialization and population have a negative impact on the environmentthrough the discharge of waste containing heavy metals. The aim of this work is to assessthe sorption capacity of a modified low cost adsorbent (cedar) on the removal of lead,nickel and zinc ions from aqueous solutions at 60 mg/L for each metal. Alkaline treatmentwas applied to cedar to improve the adsorption process by the activation of the sorptionsites. Kinetic assays were performed in batch mode at different adsorbent concentrations,from 0.5 g/L to 7.5 g/L. The pH of zero point of charge obtained for modified cedar was5.13. Scanning Electron Microscopy-Energy Dispersive Spectroscopy was used tocompare the morphology and chemical composition of the unmodified and modifiedcedar. The results revealed that alkaline treatment with potassium hydroxide is effectiveon the removal of these metals from aqueous solutions. The adsorption of lead (II), nickel(II) and zinc (II) onto modified cedar is dependent on the adsorbent concentration, beingthe maximum uptake reached for each ion at 2.5 g/L, 25.8 mg/g for Pb and 7.7 mg/g forNi and Zn.