Glyphosate waste water low-discharging and mother liquor recycling method

Abstract

The invention relates to a glyphosate waste water low-discharging and mother liquor recycling method comprising the following steps: (1) taking mother liquor left after an original glyphosate medicineis crystallized, precipitated and separated in the process of preparing glyphosate by an iminodiacetic acid method as glyphosate mother liquor; (2) carrying out hyperfiltration processing for the mother liquor so that the pollution index of the mother liquor is less than or equal to 5; (3) separating the mother liquor by a first-stage membrane to obtain a concentrated solution (1) with the glyphosate concentration of 2-7 percent and a dilute solution (1) with the glyphosate concentration of 0-0.1 percent, respectively collecting the concentrated solution (1) and the dilute solution (1) into astorage tank, separating the concentrated solution (1) by a second-stage membrane to obtain a concentrated solution (2) with the glyphosate concentration of 5-15 percent and a dilute solution (2) with the glyphosate concentration of 0.1-2 percent and respectively collecting the concentrated solution (2) and the dilute solution (2) into the storage tank; (4) reducing the temperature of the concentrated solution (2) to -10-25 DEG C to be crystallized, separating the concentrated solution (2) to obtain the original glyphosate medicine and filter liquor, mechanically using the filter liquor for 1-20 times, returning the dilute solution (2) to the first-stage membrane to be separated; (5) adding ammonia into the dilute solution (1) of the step (3) till the pH value of the dilute solution (1) is equal to 8-11 so as to generate methenamine.

Description

technical field [0001] The invention relates to a low discharge of glyphosate waste water and a method for recycling and utilizing the mother liquid by utilizing glyphosate raw drug crystallization, separation, and separation of mother liquid, and belongs to the field of waste water recycling treatment method manufacturing. Background technique [0002] The patent application number is 200610050151, which discloses a process for concentrating pesticide mother liquor by membrane method. In between, after the pretreatment system meets the water inlet requirements of the ultrafiltration equipment, it enters the first-level ultrafiltration membrane treatment system; 2. The low-concentration glyphosate mother liquor is separated into two strands after being separated by the ultrafiltration membrane, and the concentrated side solution returns to The raw material liquid tank, the light side enters the secondary nanofiltration membrane system; 3. The glyphosate mother liquor solutio...

AI Technical Summary

Problems solved by technology

Although this method recovers formaldehyde, it needs steam heating and consumes a lot of energy.