Synthesis and characterization of zeolite A, Fe3O4/zeolite A, and Fe2O3/zeolite A nanocomposites and investigation of their arsenic removal performance

In this research, zeolite A (Si/Al ratio of 1.57) with cubic morphology was synthesized using Na-clinoptilolite (Si/Al ratio of 5.62) by hydrothermal method. Fe3O4 and Fe2O3 nanoparticles were synthesized and scrutinized using XRD, FT-IR, EDX, and SEM. The Fe3O4 and Fe2O3 nanoparticles were successfully synthesized and proven with characterization methods. The proper temperature for maghemite synthesis was found to be 200 degrees C. Subsequently, the synthesized nanoparticles were loaded on the surface of the zeolite A. The nanocomposites were investigated and characterized by the techniques mentioned above. 1 wt.%, 3 wt.%, and 7 wt.% of magnetite were used to load in the structure of zeolite A, while only 1% of maghemite was loaded because of its good performance. All samples and their differences were comprehensively studied. Moreover, the dosage of adsorbents was 0.01 g/L and 0.05 g/L for zeolite A and its nanocomposites investigated for removing arsenic. Also, removing arsenic was studied using 0.01 g/L dosage of nano-oxides. 3 wt.% loading of magnetite was found to be the optimum loading. Moreover, zeolite A proved to be ineffective, and 0.01 g/L of nanocomposites was not very efficient in the case of removing arsenic. The optimum time and dosage for both nanocomposites were investigated as 90 min and 0.05 g/L, respectively. The Fe3O4/zeolite A and Fe2O3/zeolite A nanocomposites performed maximum arsenic removal percentages of 95.39% and 98.52%, respectively. The Fe3O4/zeolite A and Fe2O3/zeolite A proved to have better compatibility with pseudo-first order and pseudo-second order sequentially. The investigated nanocomposite with 1% or 3% loading of nanoparticles and pure nanoparticles regarding arsenic removal proved that nanoparticles dispersed uniformly with almost no agglomeration. Moreover, the nanocomposite with the same arsenate removal is more cost-efficient than a pure nanoparticle because the maximum free surface area of the nanoparticles in nanocomposites is available for arsenate ions and can be utilized for industrial usage.