Original scientific paper
https://doi.org/10.15255/CABEQ.2017.1100
Batch Adsorption of Cr(VI) Ions on Zeolite and Agroindustrial Waste
D. Kučić
orcid.org/0000-0001-8427-6482
; University of Zagreb, Faculty of Chemical Engineering and Technology, Department of Industrial Ecology, Trg Marka Marulića 19, 10 000 Zagreb, Croatia
M. Simonič
; University of Maribor, Faculty of Chemistry and Chemical Engineering, Laboratory for Water Biophysics and Membrane Processes, Smetanova ulica 17, 2000 Maribor, Slovenia
L. Furač
; University of Zagreb, Faculty of Chemical Engineering and Technology, Department of General and Inorganic Chemistry, Trg Marka Marulića 19, 10 000 Zagreb, Croatia
Abstract
Several adsorbents, such as natural zeolite clinoptilolite, modified zeolite, grape and olive wastes have been investigated for removal of chromium (VI) ions from aqueous solutions by performing batch kinetic sorption experiments. Natural zeolite, modified zeolite, grape and olive wastes have removed 5 %, 13 %, 73 % and 62 %, respectively, of Cr(VI) ions from aqueous solution. Equilibrium experimental results were fitted to Langmuir and Freundlich isotherms to obtain the characteristic parameters of each model. According to an evaluation using Langmuir equation, the maximum Cr(VI) adsorption capacity of grape waste was 108.12 mg g–1 and of olive waste 100.47 mg g–1 at pH 2. The equilibrium kinetic data were analyzed using pseudo-first-order and pseudo-second-order models, and parameters were estimated by using non-linear regression analysis. Langmuir model and pseudo-second-order model describes better the obtained results than Freundlich model and the pseudo first-order model. The adsorption of Cr(VI) ions increased
with temperature and the negative values of ΔG° for investigated adsorbents confirmed the feasibility and spontaneous nature of the adsorption process.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Keywords
grape and olive wastes; zeolite; adsorption; hexavalent chromium; kinetic analysis
Hrčak ID:
192354
URI
Publication date:
10.1.2018.
Visits: 1.978 *