Universidade do Porto. Faculdade de Engenharia (FEUP)
Abstract
Increased industrialization and population have a negative impact on the environment
through the discharge of waste containing heavy metals. The aim of this work is to assess
the 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 treatment
was applied to cedar to improve the adsorption process by the activation of the sorption
sites. 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 was
5.13. Scanning Electron Microscopy-Energy Dispersive Spectroscopy was used to
compare the morphology and chemical composition of the unmodified and modified
cedar. The results revealed that alkaline treatment with potassium hydroxide is effective
on 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, being
the maximum uptake reached for each ion at 2.5 g/L, 25.8 mg/g for Pb and 7.7 mg/g for
Ni and Zn.info:eu-repo/semantics/publishedVersio
