RU2177913C1 - Method of purifying sewage from paints - Google Patents

Abstract

FIELD: purification of industrial circulating water and sewage from chemical, textile and leather fur enterprises. SUBSTANCE: method comprises addition of freshly prepared montmoryllonite suspension in 0.1M chloric iron solution activated by acoustic oscillations. Frequency of acoustic oscillations is 22 kHz, and activation time is 3 minutes. Method makes it possible to cut down significantly duration and working hours of preparation thereof, attain high degree of purification at initial concentrations of contaminants which exceed concentration in prior art method widen field of application and retain high purification efficiently. EFFECT: move efficient purification method. 5 ex

Description

 The invention relates to methods for wastewater treatment from dyes and can be used for the treatment of industrial circulating and wastewater of chemical, textile and leather-fur enterprises.

 A known method of activation of clay, for example bentonite in 20% sulfuric acid by acoustic vibrations for 15-30 minutes. Obtained in this way the H-form of montmorillonite allows you to achieve a degree of purification from azo dye of about 80% [A. from. USSR, 343963, С 04 b 1972, BI 21, Merabishvili M.S. Bentonite clays. Tbilisi: Publishing House Mitsnierba, 1979, 308 pp. ].

 The disadvantages of the proposed method are the duration of processing by acoustic vibrations and the need for special corrosion-resistant equipment.

The closest to the proposed in essence and the achieved result is a method of wastewater treatment from anionic dyes with a raw material mixture, including aluminosilicate, salt of iron, aluminum or titanium [A. from. USSR, 1426949, C 02 F 1/28, 1988, BI 36]. The sorbent proposed for water purification contains montmorillonite in sodium form, aluminum polyoxychloride with a degree of basicity of 1.8-2.5 and water in the following ratio of components, wt. %: montmorillonite 30-47; aluminum polyoxychloride (in terms of dry matter A1C1 ₃ ) 8-13.75; water the rest. The degree of wastewater treatment from dyes reaches 80-100%, with an initial concentration of 20 mg / L.

 The disadvantages of the method are the great complexity and duration of the process of preparing the raw mixture, in addition, the use of the Na form of montmorillonite requires additional costs for the modification of the natural sorbent.

 The purpose of the invention is to reduce the dose of the sorbent and the duration of the process of its preparation, expanding the scope while maintaining a high degree of water purification from dyes.

 The object of the invention is achieved in that the wastewater treatment is carried out with a freshly prepared suspension of montmorillonite in a 0.1 M solution of ferric chloride activated by acoustic vibrations. The frequency of acoustic vibrations is 22 kHz, the duration of activation is 3 minutes.

 The method is confirmed by the following examples.

Example 1 (by a known method). Solutions of aluminum polyoxychlorides with a degree of basicity of 2 are prepared by pouring in small portions with vigorous stirring to 30 ml of a 1 M solution of A1Cl ₃ 60 ml of a 1 M solution of NaOH. The resulting solution is aged for 21 hours at 40 ^° C. To obtain montmorillonite with a ratio of exchangeable cations Na: Ca = 5: 1, montmorillonite in calcium form is treated with a 0.5 N NaCl solution with a ratio of solid and liquid phases of t: w = 1: 20. After that, the clay is washed with distilled water until a negative reaction to the chlorine ion is obtained. Then the sample is dried and ground in a mortar. To 2 g of dry powder is poured 3 ml of aluminum polyoxychloride containing 0.34 g of dry substance A1Cl ₃ . The mixture is stirred for 30 minutes. The resulting composition is added to 1 l of a direct pure blue dye solution with a concentration of 20 mg / l, stirred for 1 hour, settled and the clarified water is decanted. The degree of purification of the solution from the dye is 100%. Sorption capacity of 10 mg / g.

Example 2. 20 g of montmorillonite is poured into 200 ml of a 0.1 M solution of iron (III) chloride and treated with ultrasound at a frequency of 22 kHz for 3 minutes. To 500 ml of a model solution containing 20 mg / L of direct pure blue dye, add 1 ml of the obtained suspension (in terms of clay 0.2 g / L), mix for 5 minutes, settle and the clarified water is decanted. The concentration of the dye in purified water is With _o = 0 at a degree of purification of 100%. Sorption capacity of 100 mg / g.

Example 3. To 500 ml of a model solution containing 500 mg / l of direct pure blue dye, add 2.5 ml of a suspension (in terms of clay of 0.5 g / l) prepared as in example 2, mix for 5 minutes, defend and clarified water is decanted. The concentration of the dye in the purified water is C _ost = 8.4 mg / l with a purity of 99.7%. Sorption capacity of 983 mg / g.

Example 4. To 500 ml of a model solution containing 250 mg / l of direct black dye, add 1.5 ml of a suspension (in terms of clay 0.3 g / l), prepared as in example 2, stirred for 5 minutes, defend and clarified water is decanted. The concentration of the dye in purified water is With _OST = 0.75 mg / l with a purity of 99.7%. Sorption capacity of 890 mg / g.

Example 5. To 500 ml of wastewater after the oxidative dyeing of sheepskin in black with a dye concentration of 150 mg / l, 2.5 ml of a suspension (in terms of clay 0.5 g / l) prepared as in example 2 are added, mixed 5 minutes, defend and clarified water is decanted. The concentration of the dye in the purified water is C _oct = 1.47 mg / L with a purity of 99.8%. Sorption capacity of 291 mg / g.

From examples 1-5 it follows that the proposed method of wastewater treatment from dyes in comparison with the closest analogue allows you to:
- significantly reduce the dose of the raw mix;
- significantly increase the sorption capacity;
- reduce the duration and complexity of the preparation of the raw mix;
- to achieve a high degree of purification at initial concentrations of pollutants, much higher than the concentration in the compared method;
- expand the scope, using the resulting mixture for wastewater treatment from oxidative dyes.

 Fields of practical application: purification of industrial circulating and wastewater containing anionic and oxidizing dyes.

Claims (1)

 A method of treating wastewater from dyes, comprising contacting water with a feed mixture containing montmorillonite, characterized in that a feed mixture prepared from natural montmorillonite and iron chloride, activated by acoustic vibrations of 22 kHz for 3 minutes, is used.