A novel magnetic adsorbent was synthesized by magnetizing bentonite by APTES-Fe3O4 via a functional groupbridged interaction. The characterization of APTES-Fe3O4/bentonite was conducted via transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectrophotometer (FT-IR), thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), zeta potential analysis and BrunnerEmmet- Teller (BET). The APTES-Fe3O4/bentonite was assessed as adsorbents for methylene blue (MB) with a high adsorption capacity (91.83 mg . g(-1)). Factors affecting the adsorption of MB (such as pH, equilibrium time, temperature and initial concentration) were investigated. The adsorption process completely reaches equilibriumafter 120min and the maximumsorption is achieved at pH 8.0. The adsorption trend follows the pseudosecond order kinetics model. The adsorption data gives good fits with Langmuir isotherm model. The parameter factor RL falls between 0 and 1, indicating the adsorption ofMB is favorable. The adsorption process is endothermic with positive Delta H-0 values. The positive values of Delta G(0) confirm the affinity of the adsorbent towards MB, and suggest an increased randomness at the solid-liquid interface during the adsorption process. Regeneration of the saturated adsorbent was easily carried out via gamma-irradiation. (C) 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.