A novel adsorbent was synthesized through the entrapment of ball-milled biochar in Ca-alginate beads for the removal of aqueous Cd(II). Batch adsorption experiments were conducted to compare Cd(II) adsorption characteristics of ball-milled biochar (BMB), Ca-alginate (CA), and Ca-alginate entrapped ball milled biochar (CA-BMB). All the tested adsorbents showed excellent sorption ability. The maximum Cd (II) adsorption capacity estimated with Langmuir isotherm modeling was 251.8 mg g(-1) for CA, 227.1 mg g(-1) for CA-BMB, and 40.0 mg g(-1), for BMB. The results demonstrate that entrapment of ball-milled biochar in Ca-alginate provides a low-cost and high-effective way for the removal of aqueous Cd (II). (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.