Solvent recovery method and system for pharmaceutical and chemical high-solvent wastewater

Abstract

The invention discloses a solvent recovery method and system for pharmaceutical and chemical high-solvent wastewater. The solvent recovery method comprises the steps: carrying out the fine filtrationon high-solvent wastewater by a security filter and an ultrafiltration device to obtain a filtered solution; and treating the filtered solution again by using a security filter and an AMS nano filtration device to obtain a recovered solvent. The recovery system comprises a raw water tank, the raw water tank is sequentially connected with a raw water booster pump, a first security filter and an ultrafiltration device through pipelines, the water outlet of the ultrafiltration device is connected with a transfer water tank through a pipeline, and the water return port of the ultrafiltration device is connected with the raw water tank through a pipeline; the transfer water tank is sequentially connected with a concentrated solution booster pump, a second security filter, a high-pressure pump and an AMS nano filtration device through pipelines, the water production port of the AMS nano filtration device is connected with a terminal water tank through a pipeline, and the water return port ofthe AMS nano filtration device is connected with the transfer water tank through a pipeline. The method has the characteristic of convenient operation and is capable of effectively improving the solvent purification effect and increasing the circulating water utilization rate.

Description

Technical field [0001] The invention relates to a recovery and treatment system for high-solvent wastewater in pharmaceutical and chemical industries, in particular to a solvent recovery method and system for high-solvent wastewater in pharmaceutical and chemical industries. Background technique [0002] Most of the production processes in the pharmaceutical and chemical industry involve multiple links such as synthesis, extraction, and distillation. The production process also introduces a large number of organic substances such as solvents, auxiliaries and catalysts. When the chemical reaction process is incomplete or the solvent medium is used in the production process, It will cause the wastewater to contain various organic acids, alcohols, aldehydes, ketones, ethers and epoxides and other substances, with high levels of pollutants; resulting in complex pollutants in production wastewater, high levels of toxic and hazardous substances, and high salt content in some wastewater ...

AI Technical Summary

Problems solved by technology

For the recovery and treatment of solvent wastewater such as dichloromethane, the existing solvent recovery treatment mainly adopts the dehydration method to reduce the moisture content in the solvent and remove other organic components; the dehydration method mainly uses a dehydrating agent for dehydration. Dehydrating agent, acid dehydrating agent and neutral dehydrating agent, alkaline dehydrating agent such as calcium hydride and acid dehydrating agent, neutral dehydrating agent such as molecular sieve; they can reduce the moisture in the solvent to about 0.5%; but this operation is more troublesome, Not only is it difficult to remove other organic components, but it also involves the problem of recycling. The water content of the recovered solvent and other organic components are still relatively high, and the recovery effect is not ideal.

Moreover, in this process, the discharge of waste water is also relatively large, and the utilization rate of water circulation is also low.

Therefore, the existing technology has the problems of troublesome operation, unsatisfactory purification effect and low water recycling rate.

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