Removal of Cd(II) Ions from Aqueous Solution by Adsorption on ZnCl2-Activated Carbon: Equilibrium and Kinetic Study
Present study describes the adsorptive removal of Cd(II) ions from aqueous solution using activated carbon prepared from sweet lime peels (a fruit processing industry waste) treated with zinc chloride (ZnCl2) in impregnation ratio 1:1 (w/w) followed by carbonization at 500 °C for 2 h. The ZnCl2-activated carbon obtained was characterized by proximate analysis, surface textural characterization, surface charge etc. An effect of pH, temperature and contact time on Cd(II) ion removal efficiency of activated carbon was investigated in batch mode to establish optimum adsorption conditions. Adsorption equilibrium data analysis for the temperature range 303–323 K showed best fit in Langmuir adsorption isotherm. Maximum adsorption capacity was observed to be 110.98 mg g−1 at 323 K. Adsorption of Cd(II) ions on activated carbon followed the Pseudo-second-order kinetics from which activation energy for Cd(II) ion adsorption was determined to be 31.27 kJ mol−1 and indicate the chemisorption phenomenon.
KeywordsAdsorption Activated carbon Cadmium Isotherm Kinetics
The authors are very much thankful to the TEQIP-II, funded by MHRD, Government of India, Delhi (India) for providing financial support to carry out this work.
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