MnO₂/Al₂O₃ adsorption of glyphosate and microwave UV coupling degradation and regeneration process

The MnO₂/Al₂O₃ was made through mixing and calcinations, which was used to adsorb the glyphosate, and then the adsorbed glyphosate was placed in a microwave UV coupling system for degradation and regeneration. The optimal synthesized conditions of MnO₂/Al₂O₃ were studied, and the optimum experimental conditions for glyphosate adsorption and degradation by microwave coupling with UV were given. The optimum conditions for synthesizing MnO₂/Al₂O₃ was 15% (mass fraction) of MnO₂ and calcined at 500℃ for 2 h. The maximum adsorption amount of MnO₂/Al₂O₃ for glyphosate was 75 mg/g at normal temperature. The optimized parameters of microwave UV coupling process were 500 watts of power at a ventilatory volume of 0.06 m³/h for 25 min. The regeneration rate of MnO₂/Al₂O₃ reached 85% under the optimum operating conditions, and MnO₂/Al₂O₃ can be recycled many times. Glyphosate eventually degraded to carbon dioxide, nitrogen oxides, phosphate and water, and the rate of mineralization reached 65%.