Adsorption of Cr(VI) Ions on Magnetite Nano-Particles (Fe3O4): Kinetic and Thermodynamic Studies

Yıl 2016, , 0 - 0, 30.09.2016

Hakan Çiftçi , Bahri Ersoy

https://doi.org/10.31202/ecjse.258568

Cited By: 2

Öz

In this study, magnetite nano-particles (Fe₃O₄, MNPs) were synthesized by chemical co-precipitation method and characterized by FTIR, TEM and VSM methods at first. After that, some adsorption experiments were performed for removal of hexavalent chromium [Cr(VI)] ions from aqueous media by MNPs. Finally, thermodynamic and kinetic properties of Cr(VI) adsorption on MNPs were investigated. Mean particle size and magnetization saturation (Ms) of synthesized MNPs were about 15 nm and be 75 emug^-1, respectively. Under optimum adsorption conditions, capacity and removal percentage of Cr(VI) adsorption were found to be 33.45 mg/g and 88%, respectively. According to calculated thermodynamic parameters after adsorption experiments, Cr(VI) adsorption process was a result of endothermic reactions. Langmuir and Freundlich isotherm models were investigated and it was observed that the removal of Cr(VI) could be better described by the Langmuir model. Kinetic investigations showed that the pseudo-second-order model have a better description of the Cr(VI) adsorption.

Cr(VI) İyonlarının Manyetit Nano-Partikülleri (Fe3O4) Üzerine Adsorpsiyonu: Kinetik ve Termodinamik Çalışmalar

Öz

Bu çalışmada, hekzavalent krom [Cr(VI)] iyonlarının manyetit nano-partikülleri (Fe3O4, MNP) ile
adsorpsiyonu prosesinin kinetik ve termodinamik özelliklerinin araştırılması amaçlanmıştır. Bu amaç
doğrultusunda, ilk olarak kimyasal ikili çöktürme tekniği kullanılarak MNP sentezlendi ve elde edilen ürünler
FTIR, TEM ve VSM gibi metotlar ile karakterize edildi. Daha sonra, sulu ortamdan Cr(VI) iyonlarının
giderilmesi için MNP ile bir dizi adsorpsiyon deneyleri yapıldı. Son olarak da Cr(VI) iyonlarının MNP ile
adsorpsiyonu prosesinin kinetik ve termodinamik çalışmaları yapıldı. Sentezlenen nano-partiküllerin ortalama
tene boyutunun 15 nm ve mıknatıslanma doygunluğunun da 75 emug-1 olduğu tespit edildi. Optimum
adsorpsiyon şartlarında, adsorpsiyon kapasitesi ve Cr(VI) giderim yüzdesi sırasıyla 33.45 mg/g ve %88 olarak
hesaplandı. Adsorpsiyon deneyleri sonrası hesaplanan termodinamik parametrelere göre MNP ile Cr(VI)
adsorpsiyonu endotermik reaksiyonların sonucu oluşan bir proses olduğu söylenebilir. Langmuir ve Freundlich
izoterm modelleri araştırıldı ve adsorpsiyon prosesinin Langmuir modeli ile daha iyi açıklanabilir olduğu tespit
edildi. Kinetik araştırmalar sonucunda ise MNP ile Cr(VI) iyonlarının adsorpsiyonu için sözde-ikinci-derece
kinetik model ile daha iyi bir açıklama getirilebilir

Anahtar Kelimeler

Nano manyetit, Cr(VI), Adsorpsiyon kinetiği, Adsorpsiyon termodinamiği

Kaynakça

• APHA, “Standard Methods For the Examination of Water and Wastewater”, 19 th Ed., American Public Health Association, Washington DC. (1995).
• Sikaily, A.E., Nemr, A.E., Khaled, A. and Abdelwehab, O., “Removal of toxic chromium from wastewater using green alga Ulva lactuca and its activated carbon”, J. Hazard. Mater, 148 (2007) 216–228.
• Slooff, W., “Integrated criteria document chromium”,” Bilthoven, Netherlands, National Institute of Public Health and Environmental Protection, (Report no. 758701002) (1989).
• Li, H., Li, Z., Liu, T., Xiao, X., Peng, Z. and Deng, L., “A novel technology for biosorption and recovery hexavalent chromium in wastewater by bio-functional magnetic beads”, Bioresour. Technol, 99 (2008) 6271–6279.
• World Health Organization (WHO), “Guidelines for drinking-water quality”, 3rd ed., (2004) 1:334, Geneva
• World Health Organization (WHO), “Chromium, Environmental Health Criteria”, No:61 (1988) Geneva.
• Dhungana, T.P. and Yadav, P.N., “Determination of Chromium in Tannery Effluent and Study of Adsorption of Cr(VI) on Sawdust and Charcoal from Sugarcane Bagasses”, J. Nepal Chem. Soc., 23 (2009) 2008/2009.
• Çiftçi, H., Ersoy, B., Evcin, A., “Synthesis and Characterization of Superparamagnetic Magnetite/Modified Magnetite Nano-Particles (Fe3O4@SiO2@L)”, Nano Materials for Energy and Environment (NanoMatEn 2016), 01- 03 June 2016, Paris – France.
• Farimani, M.H., Shahtahmasebi, N., RezaeeRoknabadi, M., Ghows, N. and Kazemi, A., “Study of structural and magneticproperties of superparamagnetic Fe3O4/SiO2 core–shell nano composites synthesized with hydrophilic citrate-modified Fe3O4 seeds via a sol–gel approach”, Physica E, 53 (2013) 207–216.
• Zhao, X., Shi, Y., Wang, T., Cai, Y., Jiang, G., “Preparation of silica-magnetite nanoparticle mixed hemimicelle sorbents for extraction of several typical phenolic compounds from environmental water samples”, Journal of Chromatography A, 1188 (2008) 140–147.
• Garg, U.K., Kaur, M.P., Garg, V.K. and Sud, D., “Removal of nickel (II) from aqueous solution by adsorption on agricultural waste biomass using a response surface methodological approach”, Bioresour. Technol., 99(5) (2008) 1325–1331.
• Namasivayam, C., Sangeetha, D., “Recycling of agricultural solid waste coir pith: removal of anions, heavy metals, organics and dyes from water by adsorption onto ZnCl2 activated coir pith carbon”, J. Hazard. Mater., 135 (2006) 449–452.
• Hamadi, N.K., Chen, X.D., Farid, M.M. Lu, M.G.Q., “Adsorption kinetics for the removal of chromium (VI) from aqueous solution by adsorbents derived from used tyres and sawdust”, Chem. Eng. J. 84 (2001) 95–105.
• Langmuir İ., “The adsorption of gases on plane surfaces of glass, mica and platinum”, Journal of American Chemical Society, 40(9) (1918) 1361-1403.
• Masel, A.I., “Principles of adsorption and reaction on solid surfaces”, Wiley, New York (1996).
• Chiou, M.S., “Equilibrium and kinetic modeling of adsorption of reactive dye on cros linked chitosan beads”, Chemosphere, 50 (2002) 1095-1105.
• Freundlich, H.M.F., “Over the adsorption in solution”, Journal of Physical Chemistr, 57(385) (1906) 292.
• Ngomsik, A.F, Bee, A., Draye, M., Cote, G., Cabuil, V., Magnetic nano and microparticles for metal removal and environmental applications: a review, Comptes Rendus Chimie, 8(6–7) (2005) 963-970.