Synthesis of an innovative calcium-alginate magnetic sorbent for removal of multiple contaminants

A new calcium-alginate magnetic sorbent has been prepared by an electrostatic extrusion technique. The sorbent has the calcium alginate as a bio-polymeric shell and iron oxides as magnetic cores. It is characterized by a multifunctional property: ease in separation via magnetic force, and effective adsorption of arsenic(V) and copper ions. It has been found that the equilibrium time of copper and arsenic(V) can be attained in less than 3 and 25 h, respectively. The maximum adsorption capacities of arsenic and copper ions are 6.75 and 60.24 mg/g, respectively, which are much higher than those of commercial adsorbents. Solution pH plays a key role in adsorption. The adsorption of arsenic increases as the pH is decreased. On the other hand, higher pH can enhance adsorption of copper ions.