This study utilizes computational chemistry analysis (molecular dynamics and ab initio simulations) in order to understand the nature of adsorption of cyanide from aqueous solution by activated carbon and to compare the adsorption mechanism between activated and magnetic activated carbons. In addition, real adsorption mechanism of cyanide was investigated by laboratory adsorption tests using apricot plain (AAC) and magnetic activated (AMAC) carbon. The morphology, structure and property of AAC and AMAC were determined by BET, XRD, XRF and magnetometer, respectively. The simulation results reveal that the adsorption mechanism of cyanide on AAC and AMAC is nearly similar. Modifying the graphite surface with magnetite to mimic magnetic activated carbon does not have any significant influence on cyanide adsorption. The experimental results also support this fact to some extent as the maximum monolayer adsorption capacities of AAC and AMAC are very close with each other, 61.56 and 59.71 mg/g, respectively. Although iron impregnation does not significantly affect the removal of cyanide, considering the magnetic property of AMAC which can be removed easily by a magnetic separator, AMAC may be better sorbet than AAC and commercial activated carbon. (C) 2014 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.