Pretreatment method for glyphosate industrial waste water

Abstract

A pretreatment method for glyphosate industrial waste water relates to the technical field of the treatment method for the industrial waste water from pesticides. The invention provides the pretreatment method for the glyphosate industrial waste water, which can remove glyphosate, sodium chloride and reduce COD cr value. The pretreatment method can effectively remove the vast majority of sodium chloride and glyphosate in the glyphosate industrial waste water by adopting steps such as adjusting Ph value, catalytic oxidation, calcification phosphorus removal, triple effect evaporation crystallized sodium chloride removal and the like, and greatly reduces COD cr value; the pretreated waste water can be discharged into a follow-up biochemical treatment system for biochemical treatment, thus causing waste water to be discharged after reaching standards, being beneficial to the protection of the environment and having good social benefits.

Description

technical field [0001] The invention relates to a treatment method for pesticide production wastewater, more specifically, to a pretreatment method for glyphosate production wastewater. Background technique [0002] The chemical name of glyphosate is N-phosphonomethylglycine (PMG). It is a highly efficient, low-toxic and broad-spectrum organic phosphorus herbicide. The control of weeds is very effective, and it has been widely used in current agricultural production, and it is the variety with the largest output of herbicides at present. At present, most glyphosate production enterprises in my country use glycine, paraformaldehyde, and dimethyl phosphite as raw materials to produce glyphosate products with a content of 95% through condensation, hydrolysis, crystallization, and filtration. And in the process of applying this method to produce glyphosate, a large amount of polluting waste water can be produced, because contain the sodium chloride of high concentration in this...

AI Technical Summary

Problems solved by technology

And in the process of applying this method to produce glyphosate, a large amount of polluting waste water can be produced, because contain the sodium chloride of high concentration in this waste water, and contain a certain amount of glyphosate and reaction by-product, CODcr value is high, if Direct discharge will cause serious pollution to the environment, and the treatment of this wastewater has become an important research topic in the industry

[0003] Because glyphosate production wastewater contains a large amount of sodium chloride, a certain amount of organic phosphorus and reaction by-products, there are the following difficulties in the treatment: 1. If the wastewater is directly calcified to remove organic phosphorus, the resulting sediment contains a large amount of organic phosphorus. It is still a hazardous waste to the environment; 2. If the membrane treatment process is used to remove organic phosphorus, the membrane is easy to clog, and the membrane needs to be replaced frequently. The operating cost of the system is too high for the enterprise to bear; Excessive salt content in wastewater will destroy the ecological environment in which microorganisms live in the biochemical system, and ultimately fail to achieve the expected treatment effect; 4. If a common evaporator is used to concentrate and desalinate, its disadvantage is that it cannot continuously extract salt, and must be turned off after concentration and crystallization Salt is produced by steam, and intermittent production causes large steam consumption and low processing efficiency

[0004] At present, most domestic glyphosate production enterprises treat the wastewater by adding a certain amount of glyphosate dry powder after concentration to prepare 10% glyphosate water solution for sale, but this method cannot completely eliminate pollutants

With the improvement of environmental protection requirements in our country, the approval and registration of 10% glyphosate aqueous solution will be suspended, and it will gradually withdraw from the Chinese market. The above treatment methods are difficult to continue to apply

Because the waste water contains high concentration of sodium chloride, a certain amount of glyphosate and reaction by-products, it is difficult to achieve the expected effect by using biochemical treatment methods, and the treatment of this waste water has become a difficult problem faced by many glyphosate production enterprises in China

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