Magnetic nanoparticles impregnated chitosan beads (MICB) synthesized by using chitosan template was investigated for uptake capacity of arsenic in batch studies. The adsorption isotherm could be better described by the Langmuir model than the Freundlich model. The Langmuir maximum capacity of the MICB was calculated to be 35.7 mg/g for As(V), and 35.3 mg/g for As(III) at pH 6.8, respectively, which was reasonably good compared with that of other granular adsorbents reported previously. The effects of various factors such as adsorbent dose, pH, contact time, arsenic concentration and co-existing anions on arsenic removal were systematically studied. Furthermore, the as-prepared adsorbent showed an excellent arsenic removal performance in real underground water. A distinct advantage of this adsorbent was that the adsorbent could readily be isolated from solutions by application of an external magnetic field. The study of adsorption mechanism indicated that the hydroxyl groups on the adsorbent surface were involved in arsenic adsorption. (C) 2014 Elsevier B.V. All rights reserved.