Magnetic mollusk shell-Fe3O4 composite powder used as seeding adsorbent to purify Zn (II) and Pb (II) contaminated wastewater

Abstract

Biosorption of toxic heavy metal ions using inexpensive non-living biomass from aqueous solutions has been recognized as a promising technique for the decontamination of industrial effluents containing heavy metals. This chapter reports on the preparation and characterization of partially converted mollusk shell-Fe3O4 powder with sufficient magnetic saturation values. At first stage, biosorption kinetics, equilibrium and thermodynamics of Zn (II) and Pb (II) as typical aqueous heavy metal ions, onto mollusk shell-Fe3O4 composite powder were investigated in batch mode. Thereafter, the mollusk shell-Fe3O4 composite powder was explored as a seeding adsorbent to treat Zn (II) contaminated wastewater, and a lab-scale magnetically assisted water treatment system applying magnetic trap was evaluated to recover the mollusk shell-Fe3O4 powder from fluid state. In the adsorption and magnetic separation systems, Zn (II) removal and magnetic separation efficiency were used as key performance indicators. Overall equilibrium uptake capacity was 312.5 mg g-1 at 298 K and 400 mg g-1 at 318 K while∆ Hᴼads and∆ Sᴼads were determined to be-24.46 kJ mol-1 and 103.33 J mol-1 K respectively.