Efficient Treatment of Phosphorus-Containing Wastewater with Anion-Exchange Resin-Supported Nanohydrated Zirconia: Performance and Zr–P Structure Evolution Mechanism

Abstract

Zirconium (Zr)-based nanomaterials have been considered efficient in removing phosphate (P) from effluent. Compared to rough-wrought Zr(OH)4, Zr-based nanoparticles perform efficient P removal when confined in nanospace. However, the effect of nanoconfinement on the evolution of the Zr–P structure in a long-term wastewater treatment process was unclear. Herein, commercial D201 was used as a host for nanohydrous zirconium oxide (HZrO) to investigate the development of Zr–P structures. The kinetics of HZrO@D201 and the structural evolution of Zr–P in a long-term wastewater treatment process (25 days) were characterized. The competitive effects of co-existing ions (HCO3 –, SO4 2–, Cl–, and NO3 –) on phosphate adsorption were investigated. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy results illustrate the transformation from Zr–P inner-sphere complexes to zirconium phosphate nanoparticles in HZrO@D201. In short, the nanoconfinement helped HZrO@D201 to capture P quickly in P-containing wastewater treatment and induced the self-desorption behavior of HZrO@D201 in the long-term treatment process. This study provides a new perspective on the dephosphorization by zirconium-based nanomaterials and a scientific basis for applying the nanomaterials for phosphate resource mitigation and recovery from the environment.