Adsorption of Cadmium onto Activated and Non-Activated Date Pits

In this project cadmium ions were adsorbed from aqueous solutions onto either date pits; a cheap agricultural and nontoxic material, or chemically activated carbon prepared from date pits using phosphoric acid. A series of experiments were conducted in a batch adsorption technique to assess the feasibility of using the prepared adsorbents. The effects of the process variables such as initial cadmium ions concentration, contact time, solution pH and adsorbent dose on the adsorption capacity of both adsorbents were studied. The experimental data were tested using different isotherm models such as Langmuir, Freundlich, Tempkin and Dubinin- Radushkevich. The results showed that although the equilibrium data could be described by all models used, Langmuir model gave slightly better results when using activated carbon while Freundlich model, gave better results with date pits.




References:
[1] C. Namasivayam and D. Sangeetha, Journal of Hazardous Materials
B135, 449-452, 2006.
[2] T.W. Tee, and R.M. Khan, Environ. Tech. Lett., Vol. 9, pp. 1223, 1988.
[3] M.A. Ferro-garcia, J. Rivera-Utrilla, J. Rodriguez-Gordillo and I.
Bautista-Toledo, Carbon, Vol. 26, pp. 363, 1988.
[4] X.D. Zhou, and S.C. Kot.J. Envir. Hydr., Vol. 3, pp. 367, 1995.
[5] C. Namasivayam, and K. Periasamy Wat. Res., Vol. 27, pp. 1663, 1993.
[6] D.P. Tiwari, D.K. Singh and D.N. Saksena, J. Envir. Eng., Vol. 121, pp.
479, 1995.
[7] S.A. Khan, A. Riaz-ur-Rehman and M.A. Khan Waste Manage, Vol. 15,
pp. 271, 1995.
[8] I. Santiago, V.P. Worland, E. Cazares-Rivera and F. Cadena, 47th
Purdue Industrial Waste Conference Proceedings, Lewis Publishers,
Inc., Chelsea, MI., p. 669, 1992.
[9] M.H. Essa, M.A. Al-Zahrani and S. Nesaratnam "A step towards
national reliance using locally produced activated carbon from dates,"
Third Saudi Technical Conference and Exhibition (STCEX-3), Riyadh,
Saudi Arabia, pp. 291-297, 2004.
[10] M.S. Al-Sharyani "Removal of heavy metals from aqueous solutions
using local adsorbents," MSc thesis. United Arab Emirate University,
2005.