In recent years, wastewater discharged by industrial activities is often contaminated by a variety of toxic or otherwise harmful substances which have negative effects on the water environment. The industry like metal finishing and electroplating units are one of the major sources of heavy metals (Zn, Cu, Cr) and cyanide pollutants which contribute greatly to the pollution load of the receiving water bodies and therefore, increase the environmental risks.
In this present studies on enhance the removal of cyanide using activated carbon which is mainly HCN form. The effects of metal impregnation (Cu and Ag), effect of adsorbent, effects of adsorb ate concentration, temperature, pH etc, were also investigated. Kinetics and equilibrium data for cyanide removal by plain and metal-impregnated activated carbons and result shows that, the best fitted with the pseudo second-order kinetics and the Langmuir adsorption isotherms. We found that, the removal of cyanide is 19.7, 22.4 and 29.6 mg/g for plain, copper- and silver-impregnated activated carbons, respectively. Silver-impregnated activated carbon was found to be the most effective at the reduction of cyanide level in solution. The amount of Cu adsorbed was 38 mg/g with an effective removal capacity four times that of plain carbon.
Key words: Activated carbon; metal impregnation; cyanide; kinetic; isotherm
