A Novel Approach to Developing a Reusable Marine Macro-algae Adsorbent with Chitosan and Ferric Oxide for Simultaneous Efficient Heavy Metal Removal and Easy Magnetic Separation

Chitosan modified magnetic kelp biochar (Chi-KB) was successfully synthesized for efficient removal of heavy metals (Cu) from wastewater. Interestingly, the characterization results indicated that Chi-KB showed 6 times higher surface area (6.17 m/g) than the pristine magnetic kelp biochar KB (0.97 m/g). In addition, new functional groups, such as NH and CN group, have been created on the surface of biochar as a result of chitosan modification process, which in turns led to improve the Cu adsorption capacity. The effect of pH and chitosan loading on heavy metal adsorption, and competition reaction of different metal ions adsorption were also investigated. Chi-KB exhibited a separation efficiency of more than 99.8%, which allows to recovery and reusability of the adsorbent material and heavy metals simultaneously. Overall, this study highlighted the Chi-KB is a promise adsorbent for heavy metal removal without sacrificing of the separation ability using magnetism.