Technique for extracting and recovering wastewater of acephate pesticide

Abstract

This invention discloses a process for treating acephate-containing pesticide wastewater, and recovering acephate, inorganic ammonium salt, acetic acid and acetate. The process comprises: extracting wastewater with a solvent, sending the organic phase containing acephate to a solvent-removal apparatus, removing the solvent, separating, crystallizing to obtain acephate, sending extracted wastewater to a displacer, adding a strong acid to displace ammonium acetate into acetic acid and inorganic ammonium salt, or sending extracted wastewater to a neutralization apparatus, adding caustic alkali, and neutralizing to obtain acetate. The method is economic and environmentally friendly, and has such advantages as easy control and stable operation.

Description

technical field [0001] The invention belongs to a new technology for wastewater treatment and recovery, in particular to a process for treating acephate pesticide wastewater and recovering acephate, inorganic ammonium salt, acetic acid and acetate. Background technique [0002] Acephate pesticide wastewater is a kind of wastewater generated during the production process of the highly efficient and low-toxic pesticide acephate. The wastewater is colorless or light yellow liquid, slightly viscous, with a strong pesticide odor. The main pollutant contents in the wastewater are: acephate 2-4%, ammonium acetate 20-30%, ammonium sulfate 4-8%, other organic matter 2-4%, and the comprehensive COD value of the wastewater is more than 500,000 , and the waste water is extremely polluting to water bodies, and it is extremely lethal to fish and microorganisms at extremely low concentrations. It is estimated that the domestic annual production of this wastewater is 15,000-30,000 tons, a...

AI Technical Summary

Problems solved by technology

[0003] The treatment of this waste water has always been a difficult problem for various acephate pesticide manufacturers and environmental protection departments. Although some units use chemical or biological methods for treatment, they all give up because of the high cost of treatment and poor treatment effect. deal with

There are also units that use simple distillation to separate organic matter and ammonium acetate, but it has not been applied to practice because there is still a large amount of discharge of acetate and ammonia nitrogen and the obtained crude ammonium acetate cannot be refined and used.

Therefore, at present, almost all manufacturers discharge in disorder or use a large amount of tap water to dilute the discharge.