Direct Application of Sodium Alginate Solution via Dripping Technique for Effective Copper Removal and Recovery from Aqueous Solution

摘要

This study introduces the direct application of a sodium alginate solution via a dripping technique to induce effective metal recovery by the formation of crosslinked Cu~(2+) -alginate capsules. The experimental results demonstrated that the performance of Cu ~(2+) removal was highly dependent on the concentration of alginate, dose ratio of alginate to Cu~(2+) (Al/Cu ratio), and the solution pH condition as these factors immensely affect the mass transfer of Cu~(2+) into the crosslinking sites in alginate, structural alternations of Cu~(2+)-alginate capsule, and electrostatic relationship among Cu~(2+) and the functional groups present in alginate. The maximum Cu~(2+) removal efficiency of 93.1 ± 1.3% was achieved using 2.0% alginate solution, an Al/Cu ratio of 10:1, and solution pH of 4.5. Thermal treatment (calcination) for metal recovery indicates that a single-phase monoclinic CuO crystal was the sole product after a simple calcination process. Therefore, it can be concluded that the newly introduced dripping method is a potent alternative technique to provide an abridged and efficient method for heavy metal removal and recovery.