10 research outputs found
JOURNAL OF HAZARDOUS MATERIALS
The removal of heavy metals from wastewater using olive cake as an adsorbent was investigated. The effect of the contact time, pH, temperature, and concentration of adsorbate on adsorption performance of olive cake for Pb(II) and Cd(II) ions were examined by batch method. Adsorption of Pb(II) and Cd(II) in aqueous solution onto olive cake was studied in single component. After establishing the optimum conditions, elution of these ions from the adsorbent surface was also examined. The optimum sorption conditions were determined for two elements. Maximum desorption of the Pb(II) and Cd(II) ions were found to be 95.92 and 53.97% by 0.5 M HNO3 and 0.2 M HCl, respectively. The morphological analysis of the olive cake was performed by the scanning electron microscopy (SEM). (c) 2006 Elsevier B.V. All rights reserved
Identification of potential soil adsorbent for the removal of hazardous metals from aqueous phase
The present study attempted to identify the efficient hazardous
metal-removing sorbent from specific types of soil, upper and middle
layer shirasu, shell fossil, tuff, akadama and kanuma soils of Japan by
physico-chemical and metal (arsenic, cadmium and lead) removal
characterizations. The physico-chemical characteristics of soil were
evaluated using X-ray diffraction and scanning electron microscopy with
energy dispersive spectroscopy techniques, whereas metal removal
properties of soil were characterized by analyzing removal capacity and
sorption kinetics of potential metal-removing soils. The chemical
characteristics revealed that all soils are prevalently constituted of
silicon dioxide (21.83-78.58 %), aluminum oxide (4.13-38 %) and ferrous
oxide (0.835-7.7 %), whereas calcium oxide showed the highest
percentage (65.36 %) followed by silicon dioxide (21.83 %) in tuff
soil. The results demonstrated that arsenic removal efficiency was
higher in elevated aluminum oxide-containing akadama (0.00452 mg/L/g/h)
and kanuma (0.00225 mg/L/g/h) soils, whereas cadmium (0.00634 mg/L/g/h)
and lead (0.00693 mg/L/g/h) removal efficiencies were maximum in
elevated calcium oxide-containing tuff soil. Physico-chemical sorption
and ion exchange processes are the metal removal mechanisms. The
critical appraisal of three metal removal data also clearly revealed
cadmium > lead > arsenic order of removal efficiency in different
soils, except in tuff and akadama soils followed by lead > cadmium
> arsenic. It clearly signified that each type of soil had a
specific metal adsorption affinity which was regulated by the specific
chemical composition. It may be concluded that akadama would be
potential arsenic-removing and tuff would be efficient cadmium and
lead-removing soil sorbents