Synthesis and characteristics of Na-A zeolite from coal fly ash and application for adsorption of cerium(III)

Recycling rare earth elements (REEs) from waste is necessary for an environmentally sustainable reuse and wastewater management approach. Na-A zeolite was synthesized from coal fly ash (CFA) and applied for Ce3+ adsorption. Fourier transform infrared (FTIR) spectra show peaks at 790, 500 and 467 cm−1, which are bond vibrations of Si–O–Si, Si with Al–O and Si–O–. The surface area is 15.88 m2/g, with a pore size of 2.14 nm. SEM images show a cubic shape, which indicates the formation of zeolite. Field emission and energy disperse spectroscopy (EDS) shows the formation of Si, Al, Na, and O. Na-A zeolite was applied for Ce3+ adsorption. The optimum conditions for Ce3+ adsorption are 50 ppm concentration, 360 min, and pH 6. The maximum adsorption capacity is 176.49 mg/g. Based on the results, it is found that the adsorption of Ce3+ by Na-A zeolite is pseudo-second-order. The desorption test using HNO3 is more effective than using HCl and H2SO4. A desorption efficiency of 97.22 % is obtained at 4 cycles. Adsorption test using real sample wastewater demonstrates an adsorption efficiency of 83.35 %.