Cr(VI) REMOVAL FROM AQUEOUS SOLUTION ONTO AGRICULTURAL WASTE (MODIFIED SUN FLOWER HEAD WASTE): BATCH STUDIES

Abstract

In this study, removal of chromium(VI) from aqueous solution by adsorption onto agricultural waste (modified sunflower head waste) was investigated. Batch studies were conducted and effect of initial solution pH, initial concentration, adsorbent dosage, temperature, and contact time on the removal of Cr(VI) was investigated. Cr(VI) was determined by UV spectrophotometry. The maximum removal was obtained at the initial pH of 1 for initial concentration 150 mg/L, at 25 ^oC and 240 rpm. Adsorption yield increased with the increasing adsorbent dosage and temperature. Langmuir and Freundlich isotherm models were applied to data. Pseudo first order and pseudo second order kinetic models were applied to fit kinetic data. Thermodynamics parameters were also determined. The positive values of ΔH° change indicated that adsorption is endothermic. Negative values of ∆G° showed adsorption process is spontaneous. The positive ΔS° values indicated that the randomness increase. Adsorbent capacity was obtained as 7.35 mg/g.

Keywords

• Cr(VI),sunflower head waste,adsorption,batch study

References

1. Bai, R.S., Abraham, T.E., 2002. Studies on enhancement of Cr(VI) biosorption by chemically modified biomass of Rhizopus nigricans, Water Res. 36, 1224.
2. Chuah, T.G., Jumasiah, A., Azni, I., Katayon, S., Thomas Choong, S.Y., 2005. Rice husk as a potentially low-cost biosorbent for heavy metal and dye removal: an overview, Desalination 175, 305.
3. Dakiky, M., Khamis, M., Manassra, A., Mereb, M., 2002. Selective adsorption of chromium (VI) in industrial wastewater using low-cost abundantly available adsorbents, Adv. Environ. Res. 6, 533.
4. Demiral, H., Demiral, I., Tümsek, F.,. Karabacakoğlu, B., 2008. Adsorption of chromium (VI) from aqueous solution by activated carbon derived from olive bagasse and applicability of different adsorption models, Chemical Engineering Journal, 144, 188.
5. Erdem, E., Karapinar, N., Donat, R., 2004. The removal of heavy metal cations by natural zeolites, J. Colloid Interface Sci., 280, 309.
6. Ho, Y.S., 2003. Removal of metal ions from sodium arsenate solution using tree fern, Trans. I Chem E. Part B, 81, 352.
7. Keskinkan, O., Goksu, M.Z.L., Basibuyuk, M., Forster, C.F., 2004. Heavy metal adsorption properties of a submerged aquatic plant (Ceratophyllum demersum), Bioresour. Technol. 92, 197.
8. Lagergren, S., 1898. About the theory of so called adsorption of soluble substances Kungliga Stevenska Vetenskapsakademiens, Handlingar, 24(4):1-139.

9. Madoni, P., Davoli, D., Gorbi, G., Vescovi, L., 1996. Toxic Effect of heavy metals on the activated sludge protozoan community, WaterResearch, 30, 135.
10. Marquez, G.E., Ribeiro, M.J.P., Ventura, J.M., Labrincha, J.A., 2004. Removal of nickel from aqueous solutions by clay-based beds, Ceram. Int. 30, 111.
11. Ozdemir, C., Karatas, M., Dursun, S., Argun, M.E., Dogan, S., 2005. Effect of MnSO4 on the chromium removal from leather industry wastewater, Environ. Technol. 26, 397.
12. Pehlivan, E., Altun, T., 2006. The study of various parameters affecting the ion exchange of Cu2+, Zn2+, Ni2+, Cd2+, and Pb2+ from aqueous solution on Dowex50W synthetic resin, J. Hazard. Mater. B134, 149.
13. Shukla, A., Zang, Y.H., Dubey, P., Margrave, J.L., Shukla, S.S., 2002. The role of sawdust in the removal of unwanted materials from water, J. Hazard. Mater. 95,137.
14. Standard Methods for the Examination Water and Wastewater, 1985. 16th edition, APHA INC. 1740 Broadway, Newyork N.Y. 10019: 1268 p.
15. Weber, W.J. 1972. Physicochemical Processes for Water Quality Control.Wiley- Intercience: 640 p.