A new adsorbent of gadolinium-1,4-benzenedicarboxylate composite for better phosphorous removal in aqueous solutions

Phosphorus in wastewater has caused the occurrence of eutrophication. In this study, we synthesized gadolinium -1,4-benzenedicarboxylate (GdBDC), a new gadolinium composite that has not been reported, for the removal of phosphorus. The GdBDC was prepared by gadolinium with the terephthalic acid as an organic linker. It was found that the GdBDC performed very well in pH 4-9. The adsorption isotherm and kinetics were well described by the Langmuir isotherm and the pseudo-second-order kinetic equation, respectively. Furthermore, the GdBDC showed a much faster adsorption rate than many reported adsorbents; the adsorption equilibrium was established in 40-80 min that was dependent upon initial concentration; the adsorption capacity was as high as 166.91 mg/g. The effect of ionic strength and presence of other anions was insignificant for the adsorption. The uptake of phosphorus by the GdBDC was due to ligand exchange between organic linker and phosphate anion. Through this study, GdBDC was a promising and potential adsorbent for treating phosphorus containing wastewater.