How to Treat Wastewater from DMAC recovery?

In China, rectification towers are used for the rectification of crude DMAC liquid. For wastewater containing DMAC, the traditional activated sludge removal method is adopted, which uses microorganisms to degrade and consume organic matter. However, this method has a high cost and is suitable for manufacturers with basic facilities.

DMAC is an easily degradable compound. Overseas, it is also treated by conventional activated sludge process or biofilm process. If the content is high, the main problem is nitrogen removal, because the nitrogen content of DMAC is 16%.

DMAC, with the chemical name Dimethylacetamide, has the molecular formula CH₃CON(CH₃)₂, molecular weight: 87.12, and CAS No.: 127-19-5. It is a colorless and transparent liquid, low-toxic and flammable. It can be miscible with water, alcohols, ethers, esters, benzene, chloroform, aromatic compounds and other organic solvents in any proportion.

Its freezing point is -20℃, boiling point is 166℃, 96℃ (10.7kPa), 85-87℃ (4.4kPa), 74-74.5℃ (3.47kPa), 66-67℃ (2.0kPa), 62-63℃ (1.6kPa). The relative density is 0.9366 (25/4℃) and 0.9599 (0/4℃), and the refractive index is 1.4380. The flash point (open cup) is 70℃. It has low toxicity and a strong pungent odor.