Monolayer calcium-doped layered yttrium hydroxide adsorbent for rapid and efficient removal of fluoride from industrial wastewater

Strategies for the rapid and efficient removal of fluoridated industrial wastewater are currently lacking. Herein, monolayer calcium-doped layered yttrium hydroxide (Ca-Y LRH) was synthesized through formamide exfoliation, and its removal of fluoride reached equilibrium within 4 min. The adsorption kinetics fit the pseudo-second-order kinetic model with a faster adsorption rate (K F  = 0.22 mg g −1  min −1 ), and the adsorption isotherm followed the Langmuir model with a maximum adsorption capacity of 483.33 mg g −1 . The interlayer chloride ions in the monolayer Ca-Y LRH were the main ligands for substituting fluoride, which inhibited the increase in pH and maintained the continuation of the fluoride removal process. Furthermore, the optimum fluoride removal performance of monolayer Ca-Y LRH was predicted by software-based multiparameter methods and was found to be useful for treating fluoridated industrial wastewater samples (858.17 or 8.72 mg L −1 ). These findings provide novel insights into the treatment of fluoridated industrial wastewater.