This work reports the synthesis of activated carbon (AC) obtained by KOH chemical activation of spherical carbon (SC) produced from hydrothermal treatment (HT) of sucrose. Scanning electron microscopy was used to characterize the morphology and the sphere sizes of SC, which showed average diameter of 2.86 mu m. SC showed low values of BET surface area (S-BET) and total volume of pores (V-T), whereas AC presented characteristics of microporous materials with S-BET and V-T of 1534 m(2) g(-1) and 0.765 cm(3) g(-1), respectively. FT-IR analysis and Boehm method indicated that the AC surface has essentially acid functional groups, which was confirmed by pH(PZC) values of 3.0. The adsorption equilibrium data of Methylene Blue (MB) onto AC were best fitted to the Redlich-Peterson model. The maximum adsorption capacity monolayer was of 704.2 mg g(-1), which showed to be high compared to other ACs reported in the literature. The kinetic data showed better fit to the pseudo-first-order model at low MB concentration, and with the increasing of concentration, to the pseudo-second-order and Elovich models. Thermodynamic parameters indicated that MB-AC adsorption process is spontaneous and endothermic. (C) 2015 Elsevier B.V. All rights reserved.