Effective removal of aqueous glyphosate using CuFe2O4@biochar derived from phragmites

BACKGROUND The excess use of glyphosate in both agricultural and nonagricultural areas has led to tremendous health (e.g. cardiac and respiratory impacts) and environmental concerns worldwide. There is an urgent need to find efficient ways to remove glyphosate residue from the aqueous environment. RESULTS Herein, an effective method for the removal of aqueous glyphosate is developed by employing nano-CuFe 2 O 4 modified biochar (BC) as an adsorbent. The CuFe 2 O 4 @BC adsorbents were prepared through hydrolyzing phragmite powders at 500 °C, followed by a simple coprecipitation method. The influence of initial glyphosate concentration, temperature, pH, time and coexisting species on the adsorption behavior of CuFe 2 O 4 @BC to glyphosate were fully examined. CONCLUSION It was found that the adsorption of glyphosate onto CuFe 2 O 4 @BC is highly dependent on the initial glyphosate concentration, pH and temperature, as well as coexisting species. The Freundlich and Langmuir models fitted the equilibrium isotherm data well, indicating the presence of both physisorption and chemisorption. In addition, the adsorption kinetic is well described by the pseudo-second-order kinetic model, which indicated that chemical adsorption may dominate the adsorption process. The CuFe 2 O 4 @BC adsorption of glyphosate presented a maximum adsorption capacity of 269.4 mg g −1 within 240 min, under 600 mg L −1 of glyphosate solution at 298 K and pH 4; this performance exceeds all other biochar-derived adsorbents for the removal of aqueous glyphosate encountered in the open literature. Such a cost-effective, high-performance adsorbent shows a great potential for the removal of aqueous glyphosate in industry. © 2019 Society of Chemical Industry