Low-cost zeolite-based sorbents prepared from industrial perlite by-product material for Zn 2+ and Ni 2+ removal from aqueous solutions: synthesis, properties and sorption efficiency.

The conversion of waste/by-product materials into efficient sorbents is at the forefront of innovative remediation techniques. In the present study, the relationships among the synthesis conditions, physicochemical properties of synthesized sorbents and Zn and Ni removal efficiencies were studied in detail. Zeolite X, zeolite P, phillipsite, analcime, sodalite and cancrinite were synthesized from industrial perlite by-product material. The zeolite content in the synthesized sorbents and zeolite framework topology (dimensions, numbers and spatial configuration of channels) were the key factors affecting the removal of Zn and Ni from aqueous solutions. Zeolite X-based sorbent exhibited the best sorption performance mainly due to the large zeolite channel dimensions, low Si/Al ratio, high cation exchange capacity and high specific surface area. Nevertheless, the efficiency and stability of this sorbent need to be tested under field conditions prior to its application for remediation technologies.