Synthesis of porous magnetic zeolite-based material and its performance on removal of Cd2+ ion and methylene blue from aqueous solution

In this study, the natural clinoptilolite zeolite was hydrothermally treated and then combined with porous silica-coated magnetic particles to prepare a porous magnetic zeolite-based material. Process parameters such as NaOH concentration, hydrothermal temperature and time, pH value, and Fe 3 O 4 /Na 2 SiO 3 ratio were optimized. XRD , XPS, N 2 adsorption-desorption technique, SEM-EDX, TEM, FTIR, etc. were employed to investigate the composition and structure of the materials. Cd 2+ ion and methylene blue were adopted to evaluate the contamination removal performance of the materials. The results showed that hydrothermal treatment under an alkaline environment could transform clinoptilolite to Na–P zeolite with a low Si/Al ratio and relatively high Cd 2+ adsorption capacity. Porous silica-coated magnetite loading could significantly increase the specific surface area of the material and render it magnetic. The as-prepared porous magnetic zeolite-based material exhibited much higher Cd 2+ ion and methylene blue removal performance than the raw natural clinoptilolite zeolite.