Removal of Cu(II) from aqueous solutions using adsorbent based on chitosan hydrogel beads

Abstract

Mine waters and tailings resulting from mining and mineral processing often have a harmful effect on the local environment. Copper has a strong biocidal activity that greatly affects ecosystems. Therefore, the removal of copper from wastewater is of great importance to the environment. Chitosan, a natural biopolymer, obtained from chitin, the most abundant natural fiber, often has better properties than much more expensive synthetic polymers. This paper investigates the application of chitosan-based sorbents for removing copper from aqueous solutions. A novel adsorbent, chitosan hydrogel beads (CHBs), was synthesized from chitosan flakes (medium molecular weight), via ionic/covalent cross-linking. Batch experiments were carried out to optimize the process conditions for efficient removal of Cu(II) and to determine the adsorption capacity of prepared CHBs. The results showed that the maximum Cu(II) adsorption capacity estimated with Langmuir isotherm modeling was 103.6 mg/g which was three times higher than chitosan flakes (33.7 mg/g).