A Comparative Study of Adsorption of Cyanide onto Dried Peels of Plantain and Banana

Abstract

Dried plantain peels and dried banana peels were investigated for adsorption of cyanide from solution. Studies concerning the adsorption equilibrium parameters were presented and discussed. The effect of cyanide concentration, temperature, adsorbent dose, pH and contact time on cyanide adsorption were also investigated. The equilibrium data were modeled using Langmuir, Freundlich and Redlich Peterson isotherms. The adsorption equilibrium data were well explained by Freundlich isotherm. The percentage removal was found to be 83.84 % and 76.36 % at contact time of 140 minutes for Dried Plantain Peel (DPP) and Dried Banana Peel (DBP) respectively. There was a rapid increase in adsorption of cyanide from low pH of 2 to about pH of 8 and a maximum adsorption was observed at pH 10. Adsorption capacity of 53.90 mg/g and 47.56 mg/g was achieved at initial concentration of 150 mg/L for DPP and DBP respectively. The specific surface area of 5.3 m2/g and 4.4 m2/g of the adsorbents were separately determined using the method of p-nitrophenol. The result of this investigation has shown the possibility of using dried plantain peel to adsorb cyanide from waste water outweighs using dried banana peel.