混凝沉淀法处理草甘膦生产废水的试验研究

Research on the Coagulating Sedimentation Method for Treating Glyphosate Wastewater

草甘膦作为一种高效低毒的除草剂,在当前农业生产中被广泛使用。在草甘膦生产过程中,会产生大量含有机磷的废水,含量高达数十mg/L,必须采取合理有效的处理手段,减少甚至消除其对环境的污染。采用混凝沉淀法对草甘膦生产废水中的二甲酯精酯废水和甲醇回收残液进行了处理,研究了混凝剂种类、投加量、反应pH及反应时间对废水COD和TP去除效果的影响。实验表明,投加新型高分子混凝剂聚铝铁比其他几种混凝剂处理效果更好,投资运行成本更低。在混凝剂聚铝铁投加量为0.7g/L、反应pH为5、反应时间为40min时对草甘膦二甲酯精酯废水处理效果最好。此时COD的去除率可在40%以上,TP的去除率可在65%以上。在混凝剂聚铝铁投加量为0.9g/L、反应pH为4、反应时间为40min时对草甘膦甲醇回收残液废水处理效果最好,TP的去除率可在65%以上。

As an efficient and low toxicity herbicide,glyphosate is widely used in the current agricultural production.In the process of glyphosate production,it produces a lot of waste water which is full of organic phosphorus,and the organic phosphorus contained can be dozens mg/L.Therefore,the wastewater in glyphosate production process must be taken reasonable and effective means to reduce or even eliminate the pollution to the environment.In this essay,coagulating sedimentation method is taken to deal with refined dimethyl ester wastewater and glyphosate methanol recovery wastewater produced in the production process of glyphosate,studied effect of coagulant type,coagulant dosage,reaction pH and reaction time on the removal of COD and TP in the wastewater.Experiments show that adding new polymer coagulant poly aluminum and iron coagulant has a better treatment than several other coagulants,and it needs lower operating costs of investment.At the point that the amount of poly aluminum and iron coagulant added is 0.7g/L,reaction pH is 5,reaction time is 40min when dimethyl ester of glyphosate wastewater treatment works best.At this point removal efficiency of COD is more than 40%,removal efficiency of TP is over 65%.At the point that the amount of poly aluminum and iron coagulant added is 0.9g/L,reaction pH is 4,reaction time is 40min when glyphosate methanol recovery wastewater treatment works best.At this point,removal efficiency of TP is over 65%.