Study of modified ion exchange resins for phosphorus removal from glyphosate by-product salt

In order to achieve the goal of phosphate removal from glyphosate by-product salts, zirconium and zinc ions were successfully loaded onto D202 resin by co-precipitation modification method in this study, and their effectiveness in phosphate removal was evaluated under various conditions. The results of static adsorption experiments showed that the Zr/Zn@D202 resin effectively reduced the phosphate concentration in the glyphosate by-product salts from 10 mg/L to less than 0.1 mg/L, which met the national level emission standard (<i>P</i> < 0.5 mg/L). The adsorption capacity of Zr/Zn@D202 resin was 31.26 mg/g at pH 3, temperature 30 ℃, and adsorption time 2 h. The phosphate removal rate was 99.5%. The phosphate removal efficiency of Zr/Zn@D202 resin was maintained at 92% after five cycles. The samples were characterized by SEM, EDS, XRD, FT-IR and XPS. The characterization results confirmed the successful loading of zirconium and zinc ions, and elucidated that the adsorption mechanism of phosphate mainly involves the increase of the adsorption sites on the surface of the ion-exchange resin and the ion-exchange process. The pseudo-first-order model accurately described the adsorption kinetics, while the adsorption isotherms followed the Langmuir model.