针对草甘膦废水处理与磷回收难题,研究了次氯酸钠氧化草甘膦与磷酸铵镁沉淀法回收磷工艺的可行性.实验结果表明,次氯酸钠氧化草甘膦的最佳工艺条件为:次氯酸钠加入量109 g/L,溶液pH为9.0,氧化时间20 min.次氯酸钠氧化草甘膦的主要降解途径为:C—N键断裂生成羟基乙酸和乙酸;C—P键断裂生成磷酸(主要反应).正交实验得到的磷酸铵镁沉淀法回收磷的最佳工艺条件为溶液pH 9.0、镁磷摩尔比1.2、氮磷摩尔比1.4、反应时间15 min,在此条件下磷酸盐回收率达99.3％.XRD图谱证实所得固体主要成分为磷酸铵镁.%This study focused on difficulties in glyphosate wastewater treatment and phosphorus recovery,and investigated the process feasibility of sodium hypochlorite oxidation and magnesium ammonium phosphate precipitation. The optimum conditions for sodium hypochlorite oxidation were as follows:sodium hypochlorite oxidation amount 109 g/L,solution pH 9.0,reaction time 20 min. The degradation approach of glyphosate oxidized by sodium hypochlorite was that the C—N bond of glyphosate was broken to form glycolic acid and acetic acid,and the C—P bond of glyphosate was broken to form phosphoric acid which was the main oxidation product. The optimum conditions for magnesium ammonium phosphate precipitationobtained by orthogonal experiments were as follows:solution pH 9.0,mole ratio of Mg2+ to P 1.2,mole ratio of N to P 1.4,reaction time 15 min. Under these conditions,the recovery of phosphorus reached 99.3％. The main component of the solid product was confirmed as magnesium ammonium phosphate by XRD.
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