“…This suggests that a coordinate bond (Cd–C, Cd–O, and Cd–N) could be validated between Cd 2+ and the active group on the surface of SAC. 38 According to the analysis of FTIR results, the surface of the adsorbent contained some anions, such as SO 4 2− and CO 3 2− , which could exchange ions with Cd 2+ . 39 Similarly, the hydroxyl, carbonyl, and aldehyde groups on the surface of the adsorbent reacted with Cd 2+ .…”