DETERMINATION OF ADSORPTION KINETICS OF COCONUT HUSK ADSORBENT FOR HEAVY METALS REMOVAL USING LANGMUIR AND FREUNDLICH ISOTHERM EXPRESSIONS
Keywords:Langmuir, Freundlich; Equilibrium, Effluent; and Coconut husk
Adsorption of heavy metal cationic ions (Cr, Pb, and Cu) onto coconut husk carbon (CHC) adsorbent has been studied using batch-adsorption method. The study was carried out to investigate the adsorption kinetic and adsorption isotherm of the coconut husk adsorbent for the removal of heavy metals in waste liquid effluent. The influence of pH, contact time, adsorbent dose, and adsorbent concentration, and temperature on the adsorption process was also studied. Results indicated an initial increase in adsorption rate, and optimal removal of heavy metal was reached within 70 minutes, further increase in contact time and temperature show significant change in equilibrium concentration. Also, further increase in adsorbent dosage revealed significant change in the sorption capacity of the CHC. The adsorption isotherms could be fitted well by both Langmuir and Freundlich models. The RI (equilibrium parameter) value in the present investigation was less than 1 (one) which indicates that the adsorption of the heavy metals ions on the CHC is favorable. The value of n for this study which indicates the degree of non-linearity between solution concentration and adsorption were 0.31–0.39, this result indicated that the adsorption of heavy metals onto the CHC is a chemical sorption. After treatment of synthetic heavy metal solution with the CHC, the adsorption isotherm model analysis revealed that the adsorption capacity (b) of CHC for the heavy metal were 89 mg/L (Cr), 125.5 mg/L (Pb), and 129.7 mg/L (Cu). Conclusively, the results indicate that the freely abundant agricultural waste-coconut husk can be treated for heavy metal adsorption but it’s not economically viable because it’s not renewable due to the chemisorption nature of the adsorption process.
Abrowski, A. D, (2005). Adsorption - from theory to practice, Adv. Colloid Interface Sci, pg 135 - 224.
Ania, C.O., Parra, J.B., Menendez, J.A., and Pis, J.J., (2005). Effect of microwave and Conventional regeneration on the microporous and mesoporous network and on the adsorptive capacity of activated carbons; Journal of Hazardous Materials, vol 14, pg 7 - 15. DOI: https://doi.org/10.1016/j.micromeso.2005.06.013
Bansal, R.C., Donnet, J.B., and Stoeckli, F., (2005), Active Carbon; Marcel Dekker Inc., New York.
Daud, A.W., and Ali, S.W., (2004). Comparison on pore development of Activated carbon produced from palm shell and coconut shell; Journal of Environmental Science and Technology pg 63 - 69. DOI: https://doi.org/10.1016/j.biortech.2003.09.015
Gomez, Serrano. (2009), The development of an activated carbon from corn Cob and its use in the removal of Ochratoxin A from red wine. Journal of Hazardous Materials, vol 130, pg 298 - 303.
Hammed, B. H., Din, A. T., Ahmad, A. I. (2007), Adsorption of methylene blue onto bamboo-based activated carbon: kinetic and equilibrium studies, Journal of Hazardous Materials, vol 141, pp. 819 – 825.
McKay, G., Otterburn, M. S., Sweeney, A. G., (1980). The removal of colour from effluent using various adsorbents. Water Research, vol, 14, pg. 15 – 20.
Mulu, B. D., (2013), Batch Sorption Experiments: Langmuir and Freundlich Isotherm Studies for the Adsorption of Textile Metal Ions onto Teff Straw (Eragrostis tef) Agricultural Waste, Journal of Thermodynamics, vol. A, pp 6 – 11.
Reed, B. E., Matsumoto, (1993). Modeling cadmium adsorption by activated carbon using the Langmuir and Freundlich isotherm expressions. Separation Science and Technology, vol. 28, pg. 13 – 14. DOI: https://doi.org/10.1080/01496399308016742
Sun, Y., Zhang, J.P., Yang, G., and Li, Z.H., (2006), Removal of pollutants with Activated Carbon produced from K2CO3 activation of lignin from reed black Liquors, Journal of Environmental Science and Technology, vol 2, pg 429–435.
Ozer, A., Pirincci, H. B, (2006). The adsorption of Cd (II) ions on sulphuric acid-treated wheat bran. Journal of Hazardous Materials, vol 137, pg. 849 – 855.
How to Cite
With the licence CC-BY, authors retain the copyright, allowing anyone to download, reuse, re-print, modify, distribute, and/or copy their contribution. The work must be properly attributed to its author.
It is not necessary to ask for further permission from the author or journal board.
This journal provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge.