How to deal with the waste pharmaceutical intermediates to produce phosphoric acid
polyphosphoric acid is a kind of relatively stable proton acid catalyst, because it has many advantages in organic synthesis. So most pharmaceutical companies in the production of active pharmaceutical ingredients and pharmaceutical intermediates, often used to much or solvent polyphosphoric acid as the catalyst.
in the production of pharmaceutical intermediates synthesis waste emissions phosphate is bigger, because the waste phosphoric acid containing phenols, ethers, cool, alcohol or aromatic compounds, nitrogen heterocyclic and complex epoxy compounds such as a large number of organic, COD concentration is very high, can inhibit the growth of microorganism and metabolic activity, making it difficult to degradation by microorganisms, the environmental pollution is quite serious.
according to the processing of phosphoric acid, the commonly used methods are mainly physicochemical treatment and biochemical treatment method. If adopting traditional biochemical treatment process, must first for preprocessing of phosphoric acid waste liquid to reduce acid biochemical toxicity, otherwise it is hard to reach discharge standards. Physico-chemical treatment method are: direct roasting method, coagulation precipitation, adsorption, membrane separation method, solvent extraction, neutralization and advanced oxidation process and so on. Combined with the actual situation, the common method to deal effectively with solvent extraction method, the treatment effect is better than that of other methods.
solvent extraction processing, the key is to choose a suitable organic solvent, the use of organic solvents or other chemicals to dissolved organic matter in wastewater treatment and recycling, its characteristic is that the solvent should not mix with water, and dissolution of organic matter after the wastewater after extraction, extraction solvent can be reused.
liquid waste phosphoric acid with extraction agent according to certain proportion injection machine, centrifugal extraction in shell period under the action of shear force produced by the rotation of drum, some easy to form a complex material in wastewater using extraction agent and organic matter in wastewater, complete mixing and mass transfer process. After the mixture into the drum drum under the action of centrifugal force, rapid separation, complete extraction process, side by side out of the centrifuge. Organic phase in reverse extraction, extraction agent of extractant can be reused.
related extraction equipment figure:
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