In this study, magnetic characteristic was added to activated carbon (AC) obtained by ZnCl2 activation of acorn shell. The produced magnetic AC (Fe-AC) was used effectively for the removal of methylene blue (MB) from aqueous solution. The effects of different batch parameters such as adsorbent dosage (0.05-0.2 g/100 mL), initial pH (3-9), temperature (298-318 K), initial dyestuff concentration (50-250 mg/L) and contact time (5-60 min) on the adsorption process were examined. The structural and chemical characterization of the synthesized AC and Fe-AC adsorbents were carried out by using various analytical techniques such as XRD, SEM/EDS, FT-IR and BET analysis techniques. The MB concentration in the solution was determined by UV-VIS spectrophotometer. From the Langmuir isotherm model, the maximum adsorption capacity was found as 330.0 and 357.1 mg/g for AC and Fe-AC adsorbents at 298K, respectively. The investigations on the effect of the temperature and calculated thermodynamic parameters exposed the endothermic nature of the adsorption process under the studied temperature range. The adsorption/desorption cycling test indicated that the prepared Fe-AC adsorbent had good reusability performance especially up to fourth cycle. Additionally, by considering all results it was concluded that the produced AC and Fe-AC adsorbents as novel adsorbents offer a great promise for the cleaning of MB dyestuff from aqueous solutions because of the advantage of their producibility from a cheap source, high adsorption capacity and fast uptake feasibility (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.