Necla Çalışkan KILIÇ, İhsan ALACABEY, Ali Rıza KUL

Removal of cobalt ions from aqueous solution by diatomite

Diatomite (Si02.nH20) is a soft, light-color slightly sedimentary rock formed from accumulation of siliceous crusts of diatoms, which are aquatic organism from algae, and have fossil characteristics. In this study, the diatomite obtained from ÇaldıranA/an-Turkey was tested as adsorbent for Co(ll) ions adsorption from aqueous solution. Mineralogical and chemical characteristics of the diatomite, which its surface characteristics had been changed by modifying it with Mn02 (Mn-diatomite), were evaluated. Effects of surface modification, pH of the solution, temperature, initial concentration of Co(ll) ions were investigated on the adsorption of Co(ll) ions on natural and modified diatomite as a function of temperature. Experimental data were applied on Langmuir and Freundlich adsorption isotherms and model parameters were determined. Adsorption enthalpy (AH), Gibbs free enthalpy (AG) and adsorption entropy (AS) values were calculated from thermodynamic analyses.

PDF

___

1.Lemonas,.J.F., Diatomite. Am. Ceramic. Soc. Bull., 76, 92, 1997.
2.Al-Ghouti, M.A., Khraisheh, M.A.M., Tutunji, M., Flow injection potentiometric stripping analysis for study of adsorption of heavy metal ions onto modified diatomite, Chem. Eng. J., 104, 83, 2004-
3.Erdem, E., Çölgecen, G., Donat, R., The removal of textile dyes by diatomite earth, J. Coll. Int. Sci., 282, 314, 2005.
4.Köseoğlu, R., Koksal, F.,: Çiftçi, E., Akkurt, M., Identification of paramagnetic radicals in y-irradiated natural diatomite minerals by electron paramagnetic resonance, J. Mol. Struct., 733, 151, 2005.
5.Khraisheh, M.A.M., Al-Ghouti, M.A., Allen, S.J., Ahmad, M.N., Effect of OH and silanol groups in the removal of dyes from aqueous solution using diatomite, Water Res., 39, 922, 2005.
6.Al-Degs, Y., Khraisheh, M.A.M., Tutunji, M.F., Sorption of lead ions on diatomite and manganese oxides modified diatomite, Water Res., 35, 3724, 2001.
7.Alacabey, İ., Adsorption equilibrium studies on the raw and activated çaldıran diatomite (ÇaldıranA/an) of some heavy metals (cobalt, chromium, cadmium). Master of Science Thesis. University of Yüzüncü Yıl, 2006.
8.Özdilek, H.G., Distribution and transport of copper and lead in the Blackstone river. PhD Thesis, Massachusets, Worcester Polytechnic Institute, USA, 2002.
9.Türkmen, A., An investigation about the sediments and the suspended solids in the sea water of alexandretta gulf, and the heavy metal aggregation in the barbed stone oyster (Spondylus spinosus. Schreibers). PhD Thesis, Graduate School of Natural and Applied Sciences, Atatürk University, 2003.
10.Koyuncu, H„ Kul, A.R., Yıldız, N., Çalımlı, A., Ceylan, H„ J. Hazard. Mater., 141, 128, 2007.
11.Uğurlu, M., Kula, İ., Karaoğlu, H., Removal of some organic compounds using sepiolite mineral from pre-refined olive black juice. 12th National Clay Symposium Statements, Van, pp. 564-573, 2005.
12.Özcan, A.S., Erdem, B., Özcan, A., Adsorption of acid blue 193 from aqueous solutions onto Na-bentonite and DTMA-bentonite. J. Coll. Int. Sci., 280, 44, 2004.
13.Al-Ghouti, M.A., Khraisheh M.A.M., Allen, S.J., Ahmad, M.N., The removal of dyes from textile wastewater: a study of the physical characteristics and adsorption mechanisms of diatomaceous earth. J. Environ. Man., 69, 229, 2003.
14.Murray, J.W., The surface chemistry of hydrous manganesedioxide, J. Coll. Int. Sci., 46, 357, 1974.
15.Rengaraj, S., Moon, S.H., Kinetics of adsorption of Co(ll) removal from water and wastewater by ion exchange resins, Water Res., 35, 1783, 2002.
16.Murat, T., Omer, S., Mustafa, I., Adsorption of cobalt by activated carbon from the rice hulls, J. Environ. Sci. Health, 32, 2077, 1997.
17.Demirbaş, A., Adsorption of Co(ll) and Hg(ll) from water and wastewater onto modified lignin, Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 29,117,2007.