To remove glyphosate from water, nanosized copper hydroxide modified resin (D201Cu) was synthesized and characterized. The influence of NaCl concentration, temperature, pH, time, humid acid, and fulvic acid on glyphosate adsorption onto D201Cu resins were fully investigated. Glyphosate uptake on D201Cu was 113.7 mg/g in the presence 18% NaCl. The adsorption isotherms and kinetic data fitted well to the Langmuir model and pseudo-second-order model, respectively. In NaOH and NaCl mixed solution, the D201Cu regeneration efficiency can be 90% after five cycles. On the basis of the adsorption results, the schematic diagrams of adsorption mechanism of glyphosate onto D201Cu resins were proposed.

Abstract. Nano-iron and copper oxides loaded weakly basic resin D301 was investigated for the removal of glyphosate from aqueous solution. The characteristics of the resin before and after surfactant-modification were examined using scanning electron microscopy and Fourier transform infrared spectroscopy. The effects of pH, contact time, temperature and coexisting humic acid and fulvic acid were studied by batch adsorption. Adsorption of glyphosate was found strongly affected by the pH, with pH 3 providing maximum adsorption of glyphosate from aqueous solutions. The pseudo-first-order rate and pseudo-second-order rate models were applied to the experimental data. Glyphosate adsorption clearly followed the pseudo-second-order model. Moreover, fulvic acid had obvious effect on glyphosate adsorption.