The invention relates to the field of waste liquid treatment, and discloses a waste
solvent treatment method. The method comprises the following steps that: (1) reduced pressure
distillation is performed, specifically, a cleaned waste
solvent is introduced into an
evaporator for reduced pressure
distillation, after the steam of the waste
solvent passes through the top of the
evaporator, liquid enters a solvent receiving intermediate tank; (2)
drying and recycling are performed, specifically,
solid-liquid mixed impurities are : introduced into a dryer for heating, so that a gas-phase part of the solvent flows into the solvent receiving intermediate tank after being condensed; (3) primary reduced pressure rectification is performed, specifically, the solvent in the solvent receiving intermediate tank is introduced into a rectifying
tower I, light component impurities are extracted from the
tower top of the rectifying
tower I, and a product mixture is extracted from the tower kettle of the rectifying tower I; and (4) secondary reduced pressure rectification is performed, specifically, the product mixture is introduced into a rectifying tower II, monoethanolamine is extracted from thetower top of the rectifying tower II, and
ethylene glycol is extracted from the tower kettle of the rectifying tower II. With the method adopted, the problem that valuable components in the waste solvent are wasted due to the fact that the waste solvent is treated in an
incineration mode in the prior art can be solved.