SK277722B6 - Method of elaboration a liquid waste after processing of potassium salts of benzylpenicillin and phenoxymethylpenicillin - Google Patents

Abstract

Solution is release to improved elaborating of liquid waste after processing of potassium salts of benzylpenicillin and phenoxymethylpenicillin, when by treatment of mother liquors by phosphoric acid at the presence of acetone is gained crystalline dihydrogen-potassium-phosphate. After its separation is by adjustment of pH level of mother liquors by hydroxide or carbonate hydrogen sodium is gained by cooling of trihydrate sodium acetate. Used acetone is regenerated by distillations. Yielded liquid waste is submitted to biologic cleaning under substantially improved conditions, by which is raised economical and ecological contribution of processing of potassium salts of penicillin.

Description

According to the invention, the process for the treatment of liquid waste after production of the potassium salt of benzylpenicillin or phenoxymethylpenicillin consists of 40 to 85 wt. phosphoric acid in the presence of 20 to 60 vol. of acetone precipitates the desired potassium dihydrophosphate. After separation, the mother liquors obtained are crystallized with crystalline sodium bicarbonate or sodium hydroxide to a pH of 7 to 9, preferably 50 to pH 8. After cooling the resulting reaction solution to +2 to -10 ° C, the desired crystalline acetate trihydrate is separated off Sodium is distilled from the remaining liquid waste and the final liquid waste is subjected to biological treatment. 55

The process according to the invention is carried out by precipitation of liquid waste (consisting of the aqueous phase and various mother liquors) after the end of the production of the potassium salts by phosphoric acid in the presence of acetone, potassium dihydrophosphate, which is separated off. The mother liquors thus obtained, which contain a considerable amount of acetic acid in addition to the various ballast substances, are precipitated by the careful addition of crystalline sodium bicarbonate or sodium hydroxide (also crystalline or in the form of a concentrated solution) sodium acetate trihydrate, whose solubility is reduced by acetone ( 20 to 50% by volume of acetone per volume of mother liquors). Then the reaction solution is cooled to 0 C. C. After simply distilling off the acetone, the final liquid waste is subjected to biological purification and the recovered acetone is reused. The process according to the invention avoids unwanted contamination of the waste water and, moreover, is obtained in relatively high purity potassium dihydrogen phosphate and sodium acetate trihydrate, which are widely used in agriculture, in the chemical and paper industries.

DETAILED DESCRIPTION OF THE INVENTION

Example 1:

To 2000 ml of the aqueous phase containing 406.01 g of soluble inorganic substances per liter and chemical oxygen demand (COD) 404 808 mg / l formed after precipitation of benzylpenicillin with an aqueous potassium acetate solution, 879 ml of 75% acid was added in portions. The pH of the reaction mixture decreased from 6.8 to 4.0. To this mixture was added 800 mL of acetone while stirring, and the mixture was cooled to 0 C. C. The crystallized potassium dihydrogen phosphate was filtered off and washed with 1000 ml acetone. The mother liquors and washing acetone were quenched and the pH of this mixture was adjusted to pH 8.0 with stirring and cooling with sodium hydroxide. The conditioned mixture was cooled to -2 ° C and the crystallized sodium acetate trihydrate was filtered off. The mother liquors were distilled to recover the acetone used. 1414 g of 99% pure potassium dihydrophosphate and 1300 g of 98% pure sodium acetate trihydrate were obtained. The mother liquors after distillation and make-up with water contained 70.04 g / l of soluble inorganic substances, which is 17% of the original value and COD was 133 320 mg / l, which is 32.9% of the original value.

Example 2:

To 2000 ml of an aqueous phase containing 200.0 g of sol. of inorganic substances per liter and a chemical oxygen demand of 205 000 mg / l formed after precipitation of phonoxymethylpenicillin with aqueous potassium acetate solution, 420 ml of 75% phosphoric acid was added in portions, bringing the pH of the reaction mixture down from 6.7 to 3, 9th 800 mL of acetone was added to the reaction mixture and the mixture was cooled to 0 ° C. The crystallized potassium dihydrogen phosphate was filtered off and washed with 1000 ml acetone. The mother liquors and wash acetone were decanted and the pH of the mixture was adjusted to pH 8.0 with cooling and stirring with sodium hydroxide. The conditioned mixture was cooled to -6 ° C and the crystallized sodium acetate trihydrate was filtered off. The mother liquors were subjected to distillation to regenerate the acetone used. 680 g of potassium dihydrogen phosphate of 99% purity and 620 g of sodium acetate trihydrate of 97.5% purity were obtained.

Industrial usability

The process according to the invention significantly improves the treatment of waste after the production of the benzylpenicillin potassium salt and the phenoxymethylpenicillin, since it significantly reduces the salinity of the waste, allows the regeneration of the acetone used and the high quality potassium dihydrogen phosphate and sodium acetate trihydrate obtained.

Claims (1)

Process for the treatment of liquid waste after the production of the potassium salt of benzylpenicillin or phenoxymethylpenicillin, characterized in that 40 to 85 wt. phosphoric acid in the presence of 20 to 60 vol. acetone, the desired potassium dihydrogen phosphate and, after separation, the mother liquors obtained therefrom are adjusted to pH 7 to 9, preferably 8, with sodium bicarbonate or sodium hydroxide, and, after cooling the resulting reaction solution to +2 to -10 ° C, separated The desired crystalline sodium acetate trihydrate and the remaining liquid waste are distilled off by acetone and the treated liquid waste is subjected to biological purification.