In this study, we have demonstrated a simple ionic polymerization route for the fabrication of a magnetically separable adsorbent, that is, activated carbon/cobalt ferrite/alginate composite beads, for effective dye removal from aqueous solution. Adsorption characteristics of the as-fabricated magnetic beads were assessed by using methylene blue (MB) as an adsorbate. The isotherms, kinetics, and thermodynamics of the adsorption of MB onto the magnetic beads have been studied at various experimental conditions (initial dye concentration, contact time, solution pH, and temperature). The kinetics of the adsorption process was found to follow the pseudosecond-order kinetics. The equilibrium data fitted well to both the Langmuir and the Freundlich models. Various thermodynamic parameters such as the standard Gibbs energy (Delta G degrees), standard enthalpy (Delta H degrees), and standard entropy (Delta S degrees) changes were calculated. The prepared magnetic beads had a high magnetic sensitivity under an external magnetic field, which provides an easy and efficient way to separate the beads from aqueous solution.