REMOVAL OF CYANIDE FROM AQUEOUS SOLUTION BY ADSORPTION ONTO BONE CHARCOAL

Owing to its low cost, most waste has been used in various studies for removal of contaminants from water and wastewater. In this study, bone charcoal (BC) was used as an adsorbent to remove cyanide from aqueous solutions. The effect of important selected parameters including pH, cyanide initial concentration, contact time and adsorbent dosage in a batch reactor was studied. Similar data was placed into isotherm models of Freundlich, Langmuir 1, Langmuir 2, Langmuir 3 and Langmuir 4. Regression, standard deviation and error sum of squares were used to review the accuracy of kinetic data and adsorption isotherms. Maximum cyanide adsorption capacity= 140 mg/g, pH=10 and BC dose=1.5 mgl(-1) were considered the optimal conditions for cyanide adsorption process. "Pseudo second order kinetic" model was the most appropriate model for adsorbing cyanide; in addition, isotherm equilibrium studies show that Langmuir 1 is the best model for adsorbing cyanide using BC. Analyzing data by DR isotherm, it was found that cyanide adsorption onto BC is naturally a chemical one. According to data obtained from this study, BC is an adsorbent in removing cyanide and a suitable option in purifying cyanide-containing wastewater.