RU2608029C1 - Method of extracting heavy metal ions from aqueous solutions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to methods of extracting heavy metal ions by sorption on natural cellulose-containing sorbents, from solutions of different composition, formed as a result of various technological processes, and can be used to improve membrane and sorption technologies, in water treatment, in techniques for recycling heavy metal ions from aqueous solutions and waste water of different nature. Described is a method of extracting heavy metal ions from aqueous solutions, comprising contacting at room temperature for 1–20 minutes with modified polymer sorbents based on cellulose in an aqueous solution/sorbent modulus, equal to 50–200, in which modification of sorbents is carried out by depositing thereon a disodium salt of disulphonic acid of copper or cobalt phthalocyanine with ultrasonic action of operating frequency 22–44 kHz at a temperature of 90–95 °C for 30–60 min in an aqueous solution, containing disodium salt of disulphonic acid of copper or cobalt phthalocyanine 0.1–1.5 % of weight of sorbent and NaCl 3–15 % of weight of sorbent at pH 6-8 and solution/sorbent modulus of 10 followed by pressing and treatment of sorbents in solution of polyvinyl pyrrolidone with concentration of 10–50 g/l at room temperature for 5–15 s, by pressing and drying at temperature 180–200 °C to moisture content of 8–14 %.

EFFECT: technical result is higher degree of extraction of heavy metal ions from aqueous solutions and increased stability of modified sorbent during storage.

1 cl, 1 tbl, 5 ex

Description

The invention relates to methods for the extraction of heavy metal ions by sorption on natural cellulose-containing sorbents, from solutions of various compositions resulting from a variety of technological processes, and can be used to improve membrane and sorption technologies, in water treatment, in the development of technologies for the disposal of heavy metal ions from water solutions and wastewater of various nature.

A known method of wastewater treatment of industrial enterprises from heavy metals, in particular from copper ions, by sorption on sawdust treated with 4-methyl-8-oxo-5-azadecadiene-3,9-OH-2 with a sawdust-reagent mass ratio of 1 : 0.05 ÷ 0.1 [A.S. 1819669 USSR, MKI ⁵ B01J 20/22, B01J 20/30. A method of producing a sorbent for wastewater treatment of copper [Text] / Timofeeva S.S., Kukharev B.F., Stankevich V.K., Klimenko G.R .; Irkut Institute of Chemistry, Siberian Branch of the USSR Academy of Sciences. - No. 4911863/05; declared 02/15/91; publ. June 7, 93, Bull. No. 21].

However, this method of modifying sawdust is uneconomical, since it implies the use of an expensive reagent in an amount of 5-10% by weight of the sorbent, and also leads to environmental pollution.

A known method of extracting heavy metal ions from aqueous solutions by contacting them with polymer sorbents containing a cellulosic component and amino acid residues with a solution / sorbent module of 50-200. As a sorbent use meal or cake, pre-treated in aqueous enzyme solutions with a solution / sorbent module of 5-50 and an enzyme concentration of 1-10% by weight of the sorbent for 1-3 hours at a temperature of 25-40 ° C, and contacting the treated sorbent carried out for 5-20 minutes at room temperature. As a result of the use of such sorbents, the degree of extraction of Cu (II), Zn (II) and Cd (II) ions for various individual and mixed samples of meal and meal was from 78.3 to 99.9% [Pat. RF №2258560, IPC B01J 20/24. The method of extraction of heavy metal ions from aqueous solutions / Nikiforova T.E., Bagrovskaya N.A., Lilin S.A., Kozlov V.A. Applicant and patent holder State Educational Institution of Higher Professional Education "Ivanovo State University of Chemical Technology" (RUEIHTU) (RU), Institute of Solution Chemistry of the Russian Academy of Sciences (IHR RAS) (RU). - No. 2004102130/15; declared 01/26/2004; publ. 08/20/2005, Bull. Number 23. - 6 p.].

However, this method suggests the use of expensive and scarce reagents — enzymes and enzyme preparations — for pre-treatment of sorbents (100 mg of lipase obtained from Pseudomonada Cepacia costs 61.21 euros [Sigma. 2002-2003]); if lipase is produced by domestic industry, the enzyme preparation B ₁ mix is a prototype developed by genetic engineering at the Department of Enzymology of Moscow State University.

The closest in technical essence and the achieved result, that is, the prototype, is a method of extracting heavy metal ions from aqueous solutions by contacting them at room temperature for 1-20 minutes with cellulose-based polymer sorbents modified by microwave irradiation with a power of 300 W with a frequency 2.45 GHz with a solution / sorbent module of 50-200. In this case, the modification of sorbents is carried out by preliminary immersion in an aqueous solution of caprolactam or distillation residue of caprolactam with a concentration of 2-20 g / l at a module of 15-50, followed by extraction and microwave irradiation for 1-5 minutes at a temperature of 150-200 ° C and contacting the modified sorbents with aqueous solutions is carried out at a solution pH of 3-7 [US Pat. RF №2495830, IPC C02F 1/62, (2006.01), C02F 1/28 (2006.01), B01J 20/24 (2006.01), B01J 20/32 (2006.01). The method of extraction of heavy metal ions from aqueous solutions / Nikiforova T.E., Kozlov V.A., Efimov N.A .; Applicant and patent holder Federal State Budgetary Educational Institution of Higher Professional Education "Ivanovo State University of Chemical Technology" (RU). - No. 2012117931/05; declared 04/28/2012; publ. 10/20/2013, Bull. No. 29. - 6 p.].

The disadvantages of the prototype are:

- insufficiently high degree of extraction of heavy metal ions;

- insufficiently high stability of the modified sorbent during storage.

The technical result of the invention is:

- increase the degree of extraction of heavy metal ions;

- improving the stability of the modified sorbent during storage.

This result is achieved by the fact that in the method of extraction of heavy metal ions from aqueous solutions, which consists in contacting them at room temperature for 1-20 minutes with modified polymer sorbents based on cellulose with an aqueous solution / sorbent module equal to 50-200, according to the invention sorbents are modified by applying disodium salt of copper or cobalt phthalocyanine disulfonic acid upon ultrasonic treatment with an operating frequency of 22-44 kHz at a temperature of 90-95 ° C for 30-60 minutes in aq a solution containing 0.1-1.5% by weight of the sorbent of the disodium salt of copper or cobalt phthalocyanine disulfonic acid and 3-15% by weight of the NaCl sorbent at pH 6-8 and the solution / sorbent 10 module, followed by extraction and processing of the sorbents in the solution polyvinylpyrrolidone with a concentration of 10-50 g / l at room temperature for 5-15 s, spin and drying at a temperature of 180-200 ° C to a moisture content of 8-14%.

The technical result is achieved, since using the proposed modified sorbent, the degree of extraction of heavy metal ions from aqueous solutions increases and the stability of the modified sorbent during storage increases.

To implement the proposed method for the extraction of heavy metal ions from aqueous solutions, the following reagents are used:

- Disulfonic acid cobalt phthalocyanine disodium salt [TU 6-09-5508-80].

Homogeneous blue powder. The mass fraction of the disodium salt of cobalt phthalocyanine disulfonic acid is not less than 35%. Mass fraction of water-insoluble substances - not more than 1%.

Mass fraction of water - no more than 5%. The residue after sieving on a sieve with a mesh No. 056 (GOST 3584-73) is not more than 2.5%.

- Disulfonic acid phthalocyanine copper disodium salt

[Knunyants I.L., Vonsky E.V., Gusev A.A., Zhavoronkov N.M. Chemical Encyclopedic Dictionary: Reference Book - M .: Soviet Encyclopedia, 1983. - 788 p.]

• Polyvinylpyrrolidone is an amorphous linear polymer with a molecular weight of 103 to 106. Hygroscopic, soluble in water, non-toxic, has an affinity for organic polymers.

Aqueous solutions have a slightly acid reaction (pH 5) [TU 9365002-46270704-2001. Polyvinylpyrrolidone high molecular weight "Polydon"]. Polydon is a water-polymer composition in the form of a sol or gel of high molecular weight polyvinylpyrrolidone.

As sorbents used:

- short flax fiber, which is a secondary product of processing the flax industry of the following composition,%: cellulose 75 ... 78, hemicellulose 9.4 ... 11.9, lignin 3.8, pectin substances 2.9 ... 3.2, waxy substances 2, 7, nitrogen-containing substances per protein 1.9 ... 2.1, minerals 1.3 ... 2.8 [Krichevsky G.E., Korchagin M.V., Senakhov A.V. Chemical technology of textile materials. M., 1985. 640 p.];

- sawdust - waste from the woodworking industry (composition,% of absolutely dry wood: cellulose - 31.0-52.5; lignin - 19.5-30.9; pentosans - 5.3-28.3; mannan - 1, 3-11.3; galactan - 0.7-14.4; uronic acids - 2.9-8.6; substances extracted with hot water - 1.4-22.6; substances extracted with ethyl ether - 0.7 -4.6; ash - 0.2-1.0) [Nikitin V.M., Obolenskaya A.V. Schegolev V.P. Chemistry of wood and cellulose. M .: Forest industry, 1978. - 368 p.];

- cotton cellulose [GOST 595-79 "Cotton cellulose. Technical conditions];

- wood pulp [GOST 11208-82. Wood pulp (coniferous) sulfate unbleached. Technical conditions];

- Jerusalem artichoke stalks are agricultural waste of the following composition (in terms of dry matter): 55.8% carbohydrates (cellulose, hemicellulose, inulin, pectin substances), 10% protein, 18.1% nitrogen-free extractive substances 14.3% mineral substances and 1.8% fat [Ryazanova, T.V. The chemical composition of the vegetative part of Jerusalem artichoke and its use / T.V. Ryazanova, N.A. Chuprova, L.A. Dorofeeva, A.V. Bogdanov // Forest Journal. - 1997. - No. 4. - S. 71-75] /.

Jerusalem artichoke stalks are cleaned of the outer layer and crushed.

The invention is as follows.

Example 1

10 g of wood sawdust is immersed in a glass with 100 ml of an aqueous solution (module 10) with pH 6 containing 0.15 g of disodium salt of copper or cobalt phthalocyanine disulfonic acid (1.5% by weight of the sorbent) and 1.5 g of NaCl (15% by weight of the sorbent), heated to a temperature of 92 ° C and subjected to ultrasound with an operating frequency of 22 kHz for 40 minutes Then the sorbent is removed from the glass, squeezed and placed in a glass with a solution of polyvinylpyrrolidone at a concentration of 20 g / l for 7 s at room temperature, squeezed and dried at a temperature of 185 ° C to a moisture content of 14%.

The treated sorbent is poured into 0.5 l of an aqueous solution at room temperature (module 50), pH 5, containing 1.5 mmol / l of copper ions. After 10 minutes, the solution is filtered off and the content of Cu (II) ions is determined in the filtrate.

The concentration of copper ions in the solution after contacting with the sorbent was 0.268 mmol / L (recovery rate 82.1%).

Example 2

10 g of cotton cellulose is immersed in a glass with 100 ml of an aqueous solution (module 10) with a pH of 7 containing 0.01 g of disodium salt of copper or cobalt phthalocyanine disulfonic acid (0.1% by weight of the sorbent) and 0.3 g of NaCl (3% by weight of the sorbent), heated to a temperature of 93 ° C and subjected to ultrasound with an operating frequency of 44 kHz for 50 minutes Then the sorbent is removed from the glass, squeezed and placed in a glass with a solution of polyvinylpyrrolidone at a concentration of 30 g / l for 10 s at room temperature, squeezed and dried at a temperature of 190 ° C to a moisture content of 8%.

The treated sorbent is poured into 1.5 L of an aqueous solution at room temperature (module 150), pH 3, containing 1.5 mmol / L of nickel ions. After 20 minutes, the solution is filtered off and the Ni (II) ion content is determined in the filtrate. The concentration of nickel ions in the solution after contacting with the sorbent was 0.279 mmol / L (recovery rate 81.4%).

Example 3

10 g of short flax fiber is immersed in a glass with 100 ml of an aqueous solution (module 10) with pH 8 containing 0.05 g of disodium salt of copper or cobalt phthalocyanine disulfonic acid (0.5% by weight of the sorbent) and 0.8 g of NaCl (8 % by weight of the sorbent), heated to a temperature of 90 ° C and subjected to ultrasound at an operating frequency of 22 kHz for 30 minutes Then the sorbent is removed from the glass, squeezed and placed in a glass with a solution of polyvinylpyrrolidone at a concentration of 10 g / l for 5 s at room temperature, squeezed and dried at a temperature of 200 ° C to a moisture content of 12%.

The treated sorbent is poured into 2 L of an aqueous solution at room temperature (module 200), pH 6, containing 1.5 mmol / L of zinc ions. After 5 minutes, the solution is filtered off and the content of Zn (II) ions is determined in the filtrate. The concentration of zinc ions in the solution after contacting with the sorbent was 0.297 mmol / L (extraction rate 80.2%).

Example 4

10 g of wood pulp is immersed in a glass with 100 ml of an aqueous solution (module 10) with a pH of 7.5, containing 0.01 g of disodium salt of copper or cobalt phthalocyanine disulfonic acid (1.0% by weight of the sorbent) and 1.2 g of NaCl ( 12% by weight of the sorbent), heated to a temperature of 94 ° C and subjected to ultrasound at an operating frequency of 22 kHz for 60 minutes Then the sorbent is removed from the glass, squeezed and placed in a glass with a solution of polyvinylpyrrolidone at a concentration of 40 g / l for 15 s at room temperature, squeezed and dried at a temperature of 180 ° C to a moisture content of 10%.

The treated sorbent is poured into 1 l of an aqueous solution at room temperature (module 100), pH 7, containing 1.5 mmol / l of cadmium ions. After 1 min, the solution was filtered off and the content of Cd (II) ions was determined in the filtrate. The concentration of cadmium ions in the solution after contacting with the sorbent was 0.291 mmol / L (the degree of extraction of Cd (II) ions was 80.6%).

Example 5

10 g of ground Jerusalem artichoke stems are immersed in a glass with 100 ml of an aqueous solution (module 10) with a pH of 6.5, containing 0.08 g of disodium salt of copper or cobalt phthalocyanine disulfonic acid (0.8% by weight of the sorbent) and 0.7 g of NaCl (7% by weight of the sorbent), heated to a temperature of 95 ° C and subjected to ultrasound at an operating frequency of 44 kHz for 50 minutes Then the sorbent is removed from the glass, squeezed and placed in a glass with a solution of polyvinylpyrrolidone at a concentration of 50 g / l for 12 s at room temperature, squeezed and dried at a temperature of 195 ° C to a moisture content of 8%.

The treated sorbent is poured into 0.75 L of an aqueous solution at room temperature (module 75), pH 6, containing 1.5 mmol / L of copper, nickel, zinc and cadmium ions in a ratio of 1: 1: 1: 1. After 15 minutes, the solution was filtered and the content of metal ions was determined in the filtrate. The concentration of Cu (II), Ni (II), Zn (II) and Cd (II) ions in the solution after contacting with the sorbent was 0.322; 0.331; 0.333 and 0.400 mmol / L, respectively (degree of extraction 78.5; 77.9; 77.8 and 73.3%).

The results of the experiments in comparison with the prototype are presented in the table.

From the data in the table it follows that the proposed method allows to achieve the claimed technical result, namely: to increase the degree of extraction of heavy metal ions by 5-9% and to increase the storage stability of the sorbents obtained by the present method, 1.5 times (up to 18 months) compared with the prototype.

Claims (1)

The method of extraction of heavy metal ions from aqueous solutions, which consists in contacting them at room temperature for 1-20 minutes with modified polymer sorbents based on cellulose with an aqueous solution / sorbent module equal to 50-200, characterized in that the modification of the sorbents is carried out by applying to of disodium salt of copper or cobalt phthalocyanine disulfonic acid under ultrasonic treatment with a working frequency of 22-44 kHz at a temperature of 90-95 ° C for 30-60 minutes in an aqueous solution containing di disodium salt phthalocyanine or copper cobalt ultraviolet acids 0.1-1.5% by weight of the sorbent and NaCl 3-15% by weight of the sorbent at pH 6-8 and the solution / sorbent module 10 followed by extraction and treatment of the sorbents in a solution of polyvinylpyrrolidone concentration of 10-50 g / l at room temperature for 5-15 s, extraction and drying at a temperature of 180-200 ° C to a moisture content of 8-14%.