Method for treating wastewater containing methanal and methanoic acid

Abstract

The invention relates to a method for treating N-phosphonomethyl glycine (glyphosate) industrial wastewater containing high-concentration formaldehyde and formic acid. The method adopts the formaldehyde and formic acid from wastewater from sodium chlorate oxidation and wastewater treated by the method reaches biological treatment standards. Compared with the prior art, the method has the advantages that: 1, the method for preparing an aqueous solution of sodium chlorate is safe and effective and the prepared sodium chlorate has strong oxidizability; 2, the prepared aqueous solution of sodium chlorate added into the wastewater containing formaldehyde and formic acid can remove a major part of formaldehyde and formic acid in a short period, and the reaction is simple in method, quick and convenient in operation; and 3, the wastewater containing formaldehyde and formic acid is prepared into an alkali solution at a certain concentration, and chlorine is introduced into the wastewater at ahigh temperature to achieve a good formaldehyde and formic acid removal effect and greatly reduce COD, so the wastewater achieves a pretreatment effect and can be subjected to biological treatment toreach discharge standards.

Description

technical field [0001] The invention relates to waste water treatment, in particular to a method for treating waste water containing formaldehyde and formic acid. Background technique [0002] N-phosphonomethylglycine (glyphosate), as a low-toxicity, broad-spectrum herbicide, is effective against many plants and weeds, and is one of the largest-selling herbicides in the world. The traditional process mostly uses glycine as the raw material for preparation, and the current process tends to use iminodiacetic acid as the raw material, through condensation with formaldehyde and phosphorous acid to generate N-phosphonomethyliminodiacetic acid, and finally oxidized to N-phosphine Acid-methylglycine method. Whether it is the preparation of the intermediate N-phosphonomethyliminodiacetic acid or the final oxidation product N-phosphonomethylglycine, a large amount of process wastewater containing formaldehyde and formic acid will be produced in this process, and formaldehyde, The c...

AI Technical Summary

Problems solved by technology

[0006] Some people at home and abroad use biological methods to treat formaldehyde wastewater, but this method can only be used for low-concentration wastewater. This is because formaldehyde is very toxic, and it is difficult for general microorganisms to survive in high-concentration wastewater. Treatment to improve the biodegradability of wastewater, and then use biological methods for treatment

[0007] The above-mentioned methods have shortcomings in treatment efficiency, adaptability to high concentrations, and harmlessness. For example, the traditional catalytic oxidation method usually requires high temperature and high pressure, and the reaction conditions are harsh, while the biochemical method is only suitable for specific conditions with low formaldehyde content. Wastewater, in these methods there are more or less shortcomings such as formaldehyde, poor formaldehyde removal effect, and low COD reduction rate