1. NMP is an organic compound that is difficult to degrade.

NMP is the English abbreviation of N-methylpyrrolidone. It is a colorless and transparent liquid with the characteristics of low boiling point, strong polarity, low viscosity, strong solubility, and excellent chemical and thermal stability. As a relatively stable cyclic organic compound, it has the properties of difficulty in ring opening and poor biodegradability.

2. The sources of NMP wastewater are analyzed from three development stages.

In the batching stage: As a PVDF solvent, it participates in the dispersion of the slurry, forms a uniform medium, and keeps the slurry stable for a long time within a certain viscosity range.

In the coating stage: as the main liquid carrier of the slurry, it is evenly coated on the metal substrate with a stable thickness, which requires very good wettability and fluidity with the metal substrate.

In the coating baking stage: the wet film runs at a constant speed in the oven, and the solvent evaporates regularly. NMP has a pore-forming function. NMP evaporates from the wet film at a constant speed, creating a porous microelectrode structure with uniform pore size and uniform distribution. Coating machine NMP exhaust gas recovery and treatment system and waste heat recovery device through NMP exhaust gas.

3. Characteristics of NMP wastewater. These three problems affect wastewater treatment.

NMP wastewater is mainly composed of nitrogen-containing heterocyclic organic matter and contains a large amount of high-concentration COD and total nitrogen. The wastewater can be degraded by biotechnology, but sometimes it has certain biological cell toxicity and slow degradation reaction rate.

The total organic carbon content is high, the carbon-nitrogen ratio is very unbalanced, denitrification requires the consumption of a large amount of carbon sources, and huge operating costs have become the main difficulties in NMP wastewater treatment.

The smell of wastewater is strong, mainly due to the smell of NH3 dissolved gas in sewage data processing. Odor affects the health of corporate factory management employees and pollutes the control environment.

4. Treatment process, with biological treatment as the main process, removes organic matter and ammonia nitrogen in NMP wastewater.

Pool A is an anoxic pool. The existing aeration system is opened to a micro-aeration state, and the nitrated nitrogen in the returning nitrification liquid is converted into nitrogen through denitrification and removed. The NMP wastewater then enters the subsequent O pool. The O pool is an activated sludge process mode, which oxygenates and aerates the NMP wastewater. If it operates well, it has strong impact load resistance. Most of the organic matter in the NMP wastewater can be removed, and ammonia nitrogen can be achieved. The nitrification reaction converts nitrate and nitrite.