D151 resin preloaded with Fe as a salt resistant adsorbent for glyphosate from water in the presence 16% NaCl.

D151 resin preloaded with Fe [denoted as R-Fe] was to investigate R-Fe as an adsorbent for glyphosate from water in the presence high concentration of salt. The adsorption mechanism revealed the coordination of Fe inside R-Fe with O atoms of P-O and N atoms in glyphosate molecule. The adsorption capacity of glyphosate by R-Fe was much larger than that of D151 resin preloaded with Ni, Cu, Na and H. Even in glyphosate solutions containing 16% NaCl, R-Fe showed the constant adsorption capacity of glyphosate. The result provided the first evidence of R-Fe as a salt resistant adsorbent for glyphosate. The adsorption capacity of glyphosate was the maximum at pH 3.35. The adsorption thermodynamics showed that the adsorption of glyphosate by R-Fe was the ligand exchange of glyphosate and water. The maximum coordination ratio of glyphosate to Fe inside R-Fe was 1:1. The maximum adsorption capacity of glyphosate by R-Fe was up to 481.85 mg/g, which is much higher than that of other reported adsorbents in the presence 16% NaCl. 2  mol/L NaOH, 2  mol/L HSO and 2  mol/L Fe(SO) could all be used to achieve over 97% regeneration of R-Fe.