Document Type : Original Article


1 Chemistry Department, Faculty of Science, Sebha University, Sebha, Libya

2 Department of Chemistry, Faculty of Science, Sirte University, Libya


Palm kernel (PK) was activated by chemical activation (HNO3 at 230oC) to remove Ni(II) ions from aqueous solutions. Physicochemical properties of PK were reported. FT-IR analysis revealed changes in wave numbers and absorbance indicating Ni(II) adsorption onto activated carbon-PK surface. Energy dispersive X-ray fluorescence technique was used to determine the content of metals in activated carbon-PK and showed the metals found in activated carbon-PK were in recommended human usages. The maximum removal of Ni(II) ions was to be 49.7% at pH 4.6 and the equilibrium reached at 80 min. The removal efficiency of Ni(II) ions increased as the dosage of activated-PK increases and the optimum amount of activated carbon-PK dose was found to be 70 mg. The optimum pH was 4.6. The isotherm, kinetics and thermodynamics were studied. The Ni(II)- activated carbon-PK adsorption was found to follow the Freundlich isotherm based on correlation coefficient (R2) values and to be physical adsorption from the mean free energy found by Dubinin-Radushkevich, which confirmed by isothermal microcalorimetry data and the heat of sorption process using Temkin Isotherm model to be 1.58 kJ/mol. The adsorption kinetic data were described well by a second order, with the kinetic constant rates in the range of 1.82-83.5 g/g.min and was not controlled by intra-particle diffusion model. The thermodynamic studies showed that the Ni(II)-ACPK adsorption process is exothermic due to the negative values of ∆H (-30.9 J/mol) and is physical nature process due to the negative values of ∆S (-14.9 J/mol). The magnitude of Ea is 15.04 kJ/mol, which is proven the physical adsorption in nature.


1.   Hammaini, A., González, F., Ballester, A., Blázquez, M. & Munoz, J., 2007. Biosorption of Heavy Metals by Activated Sludge and Their Desorption Characteristics. Journal of environmental management, 84(4): 419-426.
2.   Krishna, R. H. & Swamy, A., 2012. Investigation on the Effect of Particle Size and Adsorption Kinetics to Removal of Hexavalent Chromium from the Aqueous Solutions Using Low Cost Sorbent. European Chemical Bulletin, 1(7): 258-262.
3.   Wang, J. & Guo, X., 2020. Adsorption Kinetic Models: Physical Meanings, Applications, and Solving Methods. Journal of Hazardous Materials, 390122156.
4.   Olayinka, K. O., Fatunsin, O. T. & Oyeyiola, A. O., 2009. Comparative Analysis of the Efficiencies of Two Low Cost Adsorbents in the Removal of Cr (Vi) and Ni (Ii) from Aqueous Solution. African Journal of Environmental Science and Technology, 3(11):
5.   Verla, A., Horsfall(Jnr), M. & Verla, E., 2012. Preparation and Characterization of Activated Carbon from Fluted Pumpkin (Telfairia Occidentalis Hook. F) Seed Shell. Asian journal of natural and applied sciences, 1(3): 39-50.
6.   Patil, A. & Shrivastava, V., 2010. Adsorption of Ni (Ii) from Aqueous Solution on Delonix Regia (Gulmohar) Tree Bark. Archives of Applied Science Research, 2(2): 404-413.
7.   Evbuomwan, B., Agbede, A. & Atuka, M., 2013. A Comparative Study of the Physico-Chemical Properties of Activated Carbon from Oil Palm Waste (Kernel Shell and Fibre). International Journal of Science and Engineering Investigations, 2(19): 75-79.
8.   Nagy, B., Maicaneanu, A., Indolean, C., Burca, S., Silaghi-Dumitrescu, L. & Majdik, C., 2013. Cadmium (Ii) Ions Removal from Aqueous Solutions Using Romanian Untreated Fir Tree Sawdust–a Green Biosorbent. Acta Chimica Slovenica, 60(2): 263-273.
9.   Singanan, M. & Peters, E., 2013. Removal of Toxic Heavy Metals from Synthetic Wastewater Using a Novel Biocarbon Technology. Journal of Environmental Chemical Engineering, 1(4): 884-890. 
10. Chakrapani, C., Babu, C., Vani, K. & Rao, K. S., 2010. Adsorption Kinetics for the Removal of Fluoride from Aqueous Solution by Activated Carbon Adsorbents Derived from the Peels of Selected Citrus Fruits. Journal of Chemistry, 7(S1): S419-S427.
11. Pradhan, B. K. & Sandle, N., 1999. Effect of Different Oxidizing Agent Treatments on the Surface Properties of Activated Carbons. Carbon, 37(8): 1323-1332.
12. Shahmohammadi-Kalalagh, S., Babazadeh, H., Nazemi, A. H. & Manshouri, M., 2011. Isotherm and Kinetic Studies on Adsorption of Pb, Zn and Cu by Kaolinite. Caspian Journal of Environmental Sciences, 9(2): 243-255.
13. Erhayem, M. & Sohn, M., 2014. Stability Studies for Titanium Dioxide Nanoparticles Upon Adsorption of Suwannee River Humic and Fulvic Acids and Natural Organic Matter. Science of the total environment, 468249-257.
14. Erhayem, M. & Sohn, M., 2014. Effect of Humic Acid Source on Humic Acid Adsorption onto Titanium Dioxide Nanoparticles. Science of the Total Environment, 47092-98.
15. Al-Anber, Z. A. & Al-Anber, M. A., 2008. Thermodynamics and Kinetic Studies of Iron (Iii) Adsorption by Olive Cake in a Batch System. Journal of the Mexican chemical society, 52 (2): 108-115.
16. Shelke, R., Madje, B., Bharad, J. & Ubale, M., 2009. Adsorption of Nickel (Ii), Copper (Ii) and Iron (Iii) from Aqueous Solution Using Ashoka Leaf Powder. International Journal of ChemTech Research, 1(4): 1318-1325.
17. Tseng, R.-L. & Wu, F.-C., 2008. Inferring the Favorable Adsorption Level and the Concurrent Multi-Stage Process with the Freundlich Constant. Journal of Hazardous Materials, 155(1-2): 277-287.
18. Salarirad, M. M. & Behnamfard, A., 2011. Modeling of Equilibrium Data for Free Cyanide Adsorption onto Activated Carbon by Linear and Non-Linear Regression Methods. in International Conference on Environment and Industrial Innovation, pp: 79-84.
19. Depci, T., Kul, A. R. & Önal, Y., 2012. Competitive Adsorption of Lead and Zinc from Aqueous Solution on Activated Carbon Prepared from Van Apple Pulp: Study in Single-and Multi-Solute Systems. Chemical engineering journal, 200224-236.
20. Erdem, E., Karapinar, N. & Donat, R., 2004. The Removal of Heavy Metal Cations by Natural Zeolites. Journal of colloid and interface science, 280(2): 309-314.
21. Ho, Y., Porter, J. & McKay, G., 2002. Equilibrium Isotherm Studies for the Sorption of Divalent Metal Ions onto Peat: Copper, Nickel and Lead Single Component Systems. Water, Air, & Soil Pollution, 141(1): 1-33.
22. Das, B., Mondal, N. K., Roy, P. & Chattaraj, S., 2013. Equilibrium, Kinetic and Thermodynamic Study on Chromium (Vi) Removal from Aqueous Solution Using Pistia Stratiotes Biomass. Chemical Science Transactions, 2(1): 85-104.
23. Atar, N., Olgun, A. & Wang, S., 2012. Adsorption of Cadmium (Ii) and Zinc (Ii) on Boron Enrichment Process Waste in Aqueous Solutions: Batch and Fixed-Bed System Studies. Chemical Engineering Journal, 1921-7.