Highly dispersed Co0.5Zn0.5Fe2O4/polypyrrole (CZFO/PPy) nanocomposites with enhanced electromagnetic properties and large surface area were rapidly and controllably prepared using microfluidic reactors. A novel magnetically controllable microdevice using the new adsorbent in a highly dispersed form was assembled and used for fluoride adsorption. Compared with traditional adsorption methods, the device displayed high adsorption efficiency and capacity. The adsorbents were regenerated with no significant loss in defluoridation ability, which indicates that the device is a realistic and highly efficient alternative way of removing fluoride pollution at low cost. (c) 2012 Elsevier B.V. All rights reserved.