efficacy evaluation of activated carbon prepared from date stones in cyanide adsorption from synthetic wastewater

Background and Aim: Availability and low cost of date stones make them useful as raw material in the preparation of activated carbon. Cyanide, because of its toxicity for humans and aquatic organisms, is one of the most important health problems. The aim of the present study was to evaluate cyanide removal from aqueous solutions and determine influencing parameters in its adsorption into activated carbon prepared from date stones. Materials and Methods: In this experimental study, activated carbon was prepared by using an electrical furnace giving out 750°C temperature for 100 min. The effect of pH (2-12), cyanide concentration (100-300 mg/L) and activated carbon dosage (0.25-2 g/L) on the absorption process were explored. All experiments were conducted in triplicate and the mean absorption rate was reported. Results: The maximum adsorption capacity of 50.21 mg/g corresponded with Langmuir model. Kinetic evaluation indicated that the adsorption of cyanide ions by the adsorbent clearly followed the pseudo-second order rate reaction. The absorption was pH dependent and the maximum adsorption was done by solutions having pH 9. At an optimum pH 9, over 97% removal of 100 mg/L cyanide was attained for an adsorbent dose of 1.25 g/L during a 40 min contact time. Conclusion: Activated carbon prepared from date stones is an efficient and low-cost adsorbent for removing of different concentrations of cyanide from water and wastewater.