SU510439A1 - The method of wastewater treatment from secondary amines - Google Patents

Description

one

The invention relates to methods for the purification of wastewater from secondary amines and can be used for the purification of wastewater from the production of repellent Ce-Cz-alkyl-diethyloxamate (Oksamat).

A known method of sewage treatment from secondary amines by adsorption of bentonite clay. However, it is not possible to purify wastewater from amines, alcohols and oxalic acid in a known manner.

For the purpose of simultaneous purification of wastewater from higher alcohols, oxalic acid and diethylamine, the effluent is alkalified with calcium hydroxide to pH 11.5-12.5, the resulting organic layer is separated, and calcium oxalate precipitate is extracted with alcohols of € 4 - Sat at the volume ratio of the phases of the extractant and water 1: 5-1: 10.

Repellent production

"Oksamat have the following characteristic

(COD - chemical absorption of oxygen):

The intensity of the smell, score5

7.7-8.9

pH 36-150

CODbichr, g O / l Content, g / l:

17.3-33.6 diethylamine 4.3-45 oxalic acid higher alcohols

0,6- 1,3 Cs Sat 0,8- 4,0

3.5

1.6- 0.5- 2.4 2.0 0.07, 0 0.00, 6 0.0-

The water treatment with calcium hydroxide is carried out to bind oxalic acid to form water insoluble calcium axalate and release diethylamine.

COO-NH2 (C., H,)

Ca (OH) +

COO-NH2 + (C, H5) (C, 04) + 2NH (CjH,) j +

For this process, it is necessary to use calcium hydroxide, in the case of using another alkali, such as caustic soda, a buffer mixture is formed (salt of oxalic acid and alkali), having a pH of 10.5-10.7. To create a pH of 11.5-12.5 in this case, an excess of alkali is required up to 150%.

At pH 11.5-12.5, the emulsion stratification occurs. The higher alcohols and their oxidation products are separated from the water as a clear organic layer.

Claims (1)

After separation of the calcium oxalate precipitate and the organic layer, dystilamine and the residual higher alcohols of the alcohols and C4-Cs are extracted from the water. Extraction of diethylamine is carried out at a pH of 11.5-12.5 and a temperature of 10-40 ° C. Conducting an extraction process at a pH above 12.5 is undesirable, as it is associated with excessive consumption of silk and water after extraction requires further neutralization. The ratio of the phases of the extractant and water 1: 5-1: 10 causes a high degree of extraction of diethylamine. At the end of the extraction, the alcohols are stripped from the water as an azeotropic mixture, and the purified water is discharged into the general sewer network of the plant and then sent for biological treatment. After purification, the water has a neutral predu, colorless, with a faint odor of alcohols (intensity of smell up to two points). The degree of purification in this method is visible from the data. Component Degree of purification from it,% Diethylamine97-99 Oxalic acid100 Higher alcohols and their oxidation products by CCPbichr95-96 Example. Sewage water with the following characteristic: Odor intensity, grade 5 pH7.7 Content, g / l: diethylamine 23.1 oxalic acid45 substances extracted with chloroform (alcohols and their oxidation products) 26 CODbichr, O / l147 are treated with 38 g of calcium hydroxide with continuous mixing / l. A precipitate of calcium oxalate and an organic layer consisting of higher alcohols and their oxidation products are separated from the water. Diethylamine and residues of higher α-alcohols are extracted from water by the method of extraction with n-butyl alcohol. The number of extractions is six, the volume ratio of phases extractant and water is 1: 5, the process temperature is 25 ° C. Purified water after stripping n-butyl alcohol has the following characteristics: pH 7.8 Chemical recovery chemicals, g O / l 7.2 Content, g / l: diethylaminates and 0.9 substances extracted with chloroform Not present The degree of purification achieved is visible from the data below. Component Degree of purification from it,% Diethylamy and 97.5 Oxalic acid100 Higher alcohols and oxidation products 100 CODBiHR95.1 Claims of the method of wastewater treatment from secondary mines, characterized in that, in order to simultaneously purify wastewater from alcohols, oxalic acid and diethylamine, the effluent is alkalized with calcium hydroxide to pH 11.5-12.5, the resulting organic layer and the precipitate of calcium xalate are separated, followed by extraction of ethylamine from water with alcohols at a volume ratio of extractant and water: 5-1: 10.