Dual removal and selective recovery of phosphate and an organophosphorus pesticide from water by a Zr-based metal-organic framework

Abstract

Zr-based metal-organic framework [Zr6(m3-O)4(m3-OH)4(OH)4(H2O)4(1,3,6,8-tetrakis(p-benzoate)pyrene) 2] (NU-1000) has been successfully used to remove phosphate and fenamiphos (an organophosphorus pesticide) from water solutions. In order to approach practical conditions, these studies have been performed under dynamic conditions and in the presence of relevant interferences, such as hydrogen carbonate. The results show that NU-1000 is able to adsorb 0.19 mol/mol of phosphate, reaching a plateau after 20 min, while 0.89 mol/mol fenamiphos is captured after 120 min. Afterward, a three-step strategy has been designed, allowing quantitative recovery of both phosphate anions and fenamiphos, separately, and ulterior adsorbent regeneration. Noteworthy, after this treatment, NU-1000 maintains a good performance toward the dual removal and selective desorption of phosphate and fenamiphos for at least two additional cycles.