The enhanced adsorption properties of phosphorus from aqueous solutions using lanthanum modified synthetic zeolites

Abstract In this study, a modified synthetic zeolite adsorbent was synthesized by the hydrothermal method using coal fly ash as the main raw material, and the enhanced phosphorus adsorption properties from aqueous solutions were then evaluated. The modification parameters were specifically studied and optimized. Moreover, the effects of initial phosphorus concentration, adsorption time, and pH value on phosphorus absorption were also investigated. The adsorbent was characterized by the energy-dispersive spectrometer analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy. Furthermore, the phosphorus adsorption properties of the zeolite adsorbent were preliminarily discussed through the perspectives of isothermal adsorption experiments, adsorption kinetics experiments, and adsorption thermodynamics calculations. The results show that the lanthanum ions were physically loaded on the surface and micropores of the adsorbent after modification, which helps to enhance the adsorption effect of phosphorus components from the aqueous solution. The phosphorus removal rate has been increased by about 65%. The adsorption process better fitted the Langmuir and Elovich equations. The theoretical calculation and analysis of adsorption thermodynamics showed that the adsorption and removal of phosphorus in water happens spontaneously.