SU827412A1 - Method of waste water purification from dyes - Google Patents

Description

one

The invention relates to the field of purification of industrial wastewater, in particular wastewater in dyeing industries of light industry.

A known method of purifying wastewater from dyes by treating them with polyacrylonitrile (PAN) modified with hydroxylamine, for which PAN is dissolved in an organic pantry body, hydrochloride sulphate oxylamine with anhydrous sodium carbonate is added and the mixture is heated, the reaction can be conducted at high temperature and pressure without the addition of sodium carbonate. The modified PAN contains an amidooxide group, formed as a result of the modification of the nitrile group with hydroxylamine 1.

The disadvantages of this method are such as the relatively high cost of the process; its duration in time; the complexity of the process, due to the need to pre-modify the PAN.

PAN is a biodegradable substance.

A method is also known that uses polyacrylic acid (Na-salt) -based polymers with a molecular weight ranging from hundreds, from thousands to several million, depending on the production method, as flocculants. These flocculants have the properties of anionic polyelectrolytes; they are most effective in the range of pH 3 .... 7, causing flocculation of positively charged sols 2.

The disadvantages of this method include the fact that their effectiveness decreases with increasing pH. In an alkaline environment, the effect of these polyelectrolytes is terminated. In addition, these polylectrolytes dissociate with the release of sodium ions,

0 increasing the salinity of the solution.

The purpose of the invention is to increase the degree of purification.

This is achieved by using the compound of the general formula as a polyelectrolyte.

-) -N

CH I COOH / p. R

where R is OCHiCHjOH, n 277-347 or R is 50eN, n 1390-ЗЗЗЗЗ, in the amount of 0.3-0.5 mg per 1 mg of dye.

The method is carried out as follows.

Wastewater dye production with a concentration of dyes up to 50 mg / l is treated with the above polyelectrolyte dose of 0.3-0.5 mg / l per 1 mg dye.

With increasing doses of polyelectrolytes, the cleaning effect does not improve, and

Comparative data on the effect of polyelectrolyte on the bleaching of dye solutions. The initial concentration of each dye 50 mg / l Dye

Astrozone olive green

Astrozon Bordeaux Astrozone Yellow Brown

Black 3

Wastewater from the dyeing production of the Saratov Production Association Nitron

thirty

Example 1. In wastewater containing Bordeaux astrozone dye with an initial concentration of 50 mg / l / polyacrylic acid-based polyelectrolyte was introduced in an amount of 0.3 mg per 1 mg of dye. The reaction mixture in the flask is stirred for 30 rvOiH. The suspension resulting from the interaction of the k1 b molecule with the polyelectrolyte is separated from the liquid phase by filtration. After filtering in solutions, the residual content of the dye is determined on a photoelectric colorimeter. The process is carried out at ordinary temperature () normal pressure without adjusting the pH.

The purification percentage is 97.2%.

Example 2. The process is carried out analogously to example 1 when the content in the waste water of the dye with a black dose of polyelectrolyte based on watering decreases in some cases (see table). The process of bleaching wastewater takes about 30 minutes to 1 hour. The resulting precipitate is flocculent, light, in small quantities can be removed by centrifuging, flotation, filtering,

Polyacrylic acid based polyelectrolytes dissolve well in water at a temperature of 20 ° C.

Comparative data indicating the advantage of the proposed parameters are given in Table 1.

Table 1

1.5

5,022

0.5

5.05

5 10 0.01

5.06.0 1.2

1.2

6.017 0.0 1.9

0.5 0.0 5.0 5.0 5.0

acrylic acid equal to 1 mg per 1 mg of the dye is stirred for -30 minutes and the residual concentration of the dye is determined.

The purge percentage is 88%.

P and i-m a p 3. The process is carried out anaogically as in example 1, with the wastewater of the dyeing production of the Saratov production association Nitron with the original

the content of dyes in them 50 mg /

at dbz polyacrylic acid-based polyelectrolyte in an amount of 0.5 mg per 1 mg of dye after stirring for 30 minutes, the residual amount of dyes in the raw water is determined.

The cleaning percentage is 100%. Comparative data on the degree of purification from dyes are presented in table 2. Dose of polyelectrolyte per 1 mg of dye, mg 0.1 1 0.2 I 0.3 G 0.4 GO, 5 1 1 G2 5 Residual concentration of dyes, mg / l

-Table 2

99 99 99 99

100 100 100 100

100 100 100 100 The proposed method for the treatment of wastewater from dyes as compared with the known method provides the possibility of discharging wastewater into the water jets due to the fact that the residual polyelectrolyte concentration in the experiments is 0.1 mg / l, which does not affect the viability of active microorganisms sludge during their biochemical tertiary treatment and does not prevent the discharge of water treated by this method into water bodies; simplification of the process by eliminating the preliminary modification of polyacrylic acid-based polyelectrolyte, carrying out the process at ordinary temperature and pressure; cheaper process due to the exclusion of scarce and expensive reagents from the process. The polyelectrolytes according to the proposed method are a polymer based on acrylic acid in (H form); its action does not depend on the pH of the medium and dissociation does not lead to an increase in the salt content of water1, which makes it possible to discharge purified water into water bodies or to be returned for reuse.

79 22 83 18

86

Claims (2)

18 Claim 1, A method for purifying waste water from dyes by treating them with polyacrylic acid-based polyelectrolytes, characterized in that, in order to increase the degree of purification, c. As a polyelectrolyte, a compound of the general formula R - (- CHQ.-CH -) - H, R COOH is used, where R is OCHiCH20H, p 277-347 or R. p 1390-8333 2. Method POP.1, characterized in that the amount of polyelectrolyte is taken 0.3-0.5 mg per 1 mg of dye. Sources of information taken into account in the examination 1, Japan Patent No. 50-36107, class, C 02 C 5/02, 1975, 2, Weizser da.I. and Mints D.M. High-molecular flocculants in water purification processes, M ,, Stroyizdat, 1975, 33 (prototype),