Equilibrium Studies for Removal of Cadmium (II) Ions Removal from Water Using Activated Carbon Derived from Macadamia Intergrifolia Nutshell Waste Powder

Abstract

Heavy metals have continued to be of great concern in research as major pollutants of water. Adsorption using low cost adsorbent is a low cost method of the removal heavy metal ions from aqueous solution. In this study activated carbon derived from macadamia intergrifolia nutshell powder was considered as an alternative low cost adsorbent for the removal of Cd(II) ions from aqueous solution. Various physicochemical parameters which included sorbent mass, and initial metal ions concentration isotherms using sorption models were determined. Results from the experiment indicated the optimum values for sorbent mass as 0.3 grams, and initial metal ions concentration as 8mg/l. Adsorption isotherms were found to fit well in Langmuir model (R2=0.9935), Javanovic model (R2 =0.9857) and Freundlich model (R2=0.9911). Additionally, for Langmuir model the value of separation factor (KL) was in the range of 0 to 1 indicating a favorable reaction. For Jovanovic model adsorption energy was found to be 1.00334 l/mg thus an indication of binding vibrations during Cd(II) ions adsorption.  FTIR spectrum revealed that the presence of O-H at νmax 3389 cm-1, COO- at νmax 2367 cm-1, C=0 at νmax 1593 cm-1,  C-O at νmax 1344 cm-1, P-O at νmax 1206 cm-1 and POO-H at νmax 1110cm-1 functional group in activated carbon enhanced Cd(II) ions removal.  The study revealed that activated carbon derived from macadamia intergrifolia nutshell can be used to remove Cd(II) ions from water.