锰盐沉淀法处理草甘膦废水的草甘膦回收试验

Reclamation of Glyphosate in Treatment of Glyphosate Wastewater by Manganese Chemical Sedimentation Process

草甘膦生产过程中产生的大量草甘膦废水至今无有效的回收方法。采用化学沉淀法处理草甘膦废水，试验结果表明：当投加的锰盐与模拟废水溶液中草甘膦的摩尔比值为1．0-1．3，p]-I为4．2。5．6时，草甘膦与锰盐反应沉淀，沉淀率可达96％以上。继续向回收的草甘膦锰盐沉淀中加酸使pH小于2．0，沉淀将重新溶解形成草甘膦过饱和溶液，静置后草甘膦重新结晶，得到纯度95％以上的草甘膦晶体。该技术应用到实际草甘膦废水处理中时，废水的高盐度和复杂成分显著降低了草甘膦的沉淀及结晶效率，限制了该技术的应用，其机理研究有着重大的理论和现实意义。

The large quantities of wastewater generated in the process of glyphosate production can not be recycled effectively now. The experiment showed that the addition of manganese salt into the aqueous solution of glyphosate（Mn2＋/glyphosate=l.0~l.3,pH=4.2~ 5.6） could precipitate over 96 % of the glyphosate. By adding acid to the precipitation and making the pH of solution less than 2.0, the precipitation could be dissolved and became supersaturated aqueous solution of glyphosate, then glyphosate would crystallize, the purity of the crystal was above 95 %. When this technique was applied to the treatment of mother liquor of glyphosate, the efficiency of precipitation and crystallization decreased remarkably due to the complexity and high salinity of the mother liquid, and the applica- tion of this technology may be limited. Thus the mechanism research was highly theoretically and practically meaningful..