RU2728998C1 - Method of heavy metal ions extraction from aqueous solutions - Google Patents

Abstract

FIELD: technological processes.

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. Method of extracting heavy metal ions from aqueous solutions is carried out by contacting them at room temperature at solution pH of 3–7 for 1–20 minutes with polymer sorbents based on cellulose, modified at microwave irradiation with power of 300 W with frequency of 2.45 GHz, wherein the sorbents are modified by pretreatment in an alcoholic solution of epichlorohydrin with concentration of 25–75 g/l at temperature of 55–65 °C for 30–60 minutes and solution/sorbent module 10–20 with subsequent squeezing, washing with distilled water and treatment in aqueous solution of diethylenetriamine, or polyethylene polyamine, or hydrochloride polyhexamethyleneguanidine with concentration of 50–100 g/l with microwave irradiation for 10–30 minutes at temperature of 30–80 °C and module solution/sorbent 10–20, washing with distilled water and drying to constant weight.

EFFECT: technical result is higher degree of extraction of heavy metal ions and low temperature of treatment of sorbents.

1 cl, 1 tbl, 5 ex

Description

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

A known method of purification of industrial wastewater 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 mass ratio of sawdust - reagent 1 : 0.05 ÷ 0.1 [A.s. 1819669 USSR, MKI ⁵ B01J 20/22, B01J 20/30. A method of obtaining a sorbent for copper wastewater treatment / Timofeeva S.S., Kukharev B.F., Stankevich V.K., Klimenko G.R. - No. 4911863/05; Appl. 02.15.91 .; Publ. 7.06.93, Bul. No. 21]. However, this method for modifying sawdust is uneconomical, since it involves the use of an expensive reagent in an amount of 5-10% of the sorbent weight, and also leads to environmental pollution.

A known method for extracting heavy metal ions from aqueous solutions by contacting them with polymer sorbents containing a cellulose component and amino acid residues with a solution / sorbent modulus equal to 50-200. As a sorbent, meal or cake is used, pretreated in aqueous solutions of enzymes with a solution / sorbent module of 5-50 and an enzyme concentration of 1-10% of the sorbent mass 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 cake ranged from 78.3 to 99.9% [US Pat. No. 2258560 RF, IPC B01J 20/24. Method of extraction of heavy metal ions from aqueous solutions / Nikiforova T.E., Bagrovskaya N.A., Lilin S.A., Kozlov V.A. applicant and patentee State educational institution of higher professional education "Ivanovo State University of Chemical Technology" (GOUVPO "IGHTU") (RU), Institute of Chemistry of Solutions of the Russian Academy of Sciences (IHR RAS) (RU). - No. 2004102130/15; declared 26.01.2004; publ. 20.08.2005, Bul. No. 23. - 6 p.].

However, this method involves the use of expensive and scarce reagents for the pretreatment of sorbents - enzymes and enzyme preparations (100 mg of lipase obtained from Pseudomonada Cepacia cost 61.21 euros [Sigma. 2002-2003]); if lipase is produced by the domestic industry, then 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 for 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 equal to 50-200. In this case, the modification of the sorbents is carried out by their preliminary immersion in an aqueous solution of caprolactam or the distillation residue of caprolactam distillation with a concentration of 2-20 g / l at a module of 15-50, followed by pressing and microwave irradiation for 1-5 minutes at a temperature of 150-200 ° C , and the contact of the modified sorbents with aqueous solutions is carried out at a pH of the solution of 3-7 [US Pat. No. 2495830 RF, IPC C02F 1/62, (2006.01), C02F 1/28 (2006.01), B01J 20/24 (2006.01), B01J 20/32 (2006.01). Method of extraction of heavy metal ions from aqueous solutions / T.E. Nikiforova, V.A. Kozlov, N.A. Efimov; applicant and patentee Federal State Budgetary Educational Institution of Higher Professional Education "Ivanovo State University of Chemical Technology" (RU). - No. 2012117931/05; declared 04/28/2012; publ. 20.10.2013, Bul. No. 29. - 6 p.].

The disadvantages of the prototype are:

- insufficiently high degree of extraction of heavy metal ions;

- high temperature of sorbent processing (150-200 ° C).

The technical result of the invention is:

- increasing the degree of extraction of heavy metal ions;

- lowering the temperature of sorbent processing.

This result is achieved by the fact that in the method of extracting heavy metal ions from aqueous solutions by contacting them at room temperature at a pH of a solution of 3-7 for 1-20 min with polymer sorbents based on cellulose, modified by microwave irradiation with a power of 300 W at a frequency of 2 , 45 GHz, according to the invention, the modification of sorbents is carried out by pretreating them in an alcoholic solution of epichlorohydrin with a concentration of 25-75 g / l at a temperature of 55-65 ^about C for 30-60 minutes and a solution / sorbent module 10-20, followed by pressing , washing with distilled water and processing in an aqueous solution of diethylenetriamine (polyethylenepolyamine, polyhexamethylene guanidine) with a concentration of 50-100 g / l under microwave irradiation for 10-30 minutes at a temperature of 30-80 ° C and a solution / sorbent module 10-20, washing with distilled water and drying to constant weight.

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

- Epichlorohydrin. GOST 12844-74 Technical epichlorohydrin. Technical conditions;

- Diethylenetriamine, N- (2-aminoethyl-1,2-ethanediamine), (H ₂ N - CH ₂ - CH ₂ - NH - CH ₂ - CH ₂ - NH ₂ , CAS 000111-40-0, - one-component product, a clear and colorless substance with a smell similar to that of ammonia;

[Kirk-Othmer encyclopedia, 3rd ed., V. 7, N.Y., 1979, p. 580.], [Chemical encyclopedia. - M .: Soviet encyclopedia. Ed. I. L. Knunyants. 1988].

- Polyethylene polyamine NH _n (CH ₂ CH ₂ NH) _n H [TU 2413-214-00203312-2002]. Liquid from light yellow to dark brown color without mechanical impurities, greenish color of the product is allowed

- Polyhexamethylene guanidine hydrochloride (PHMG-hydrochloride), (C ₇ H ₁₆ N ₃ Cl) _n , where n = 4-50, molecular weight: 700-10000 amu. CAS: 57029-18-2. PHMG-hydrochloride is a solid crystalline transparent substance, has no color and odor, is completely soluble in water, soluble in alcohol, does not lose its properties at negative temperatures, does not decompose and retains its physicochemical and biocidal properties up to a temperature of + 120 ° C, pH of 1% aqueous solution 7-10.5. [http://polyguanidines.ru - site of the Institute of Environmental and Technological Problems (ROO IETP)] or [Pat. No. 2489452 RF, IPC C08G 73/00, A 61L 2/16 (2006.01). Method of obtaining polyhexamethylene guanidine hydrochloride / Popovkin V.V., Glukhov I.S., Antonov M.I .; patentee: Limited Liability Company "Veresk Company" (RU). - No. 2012117497/05; declared 04/26/2012; publ. 08/10/2013, Bul. No. 22. - 6 s];

- short flax fiber, which is a secondary product of the processing of 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 calculated as proteins (1.9 ... 2.1), mineral substances (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 extractable with hot water - 1.4-22.6; substances extractable with ethyl ether - 0.7 -4.6; ash - 0.2-1.0) [Nikitin V.M., Obolenskaya A.V. V.P. Schegolev Chemistry of wood and cellulose. M .: Forest industry, 1978. - 368 p.];

- cotton cellulose [GOST 595-79 “Cotton cellulose. Specifications.];

- wood pulp [GOST 11208-82. Wood pulp (coniferous) sulphate unbleached. Specifications].

- Jerusalem artichoke stalks are a waste of agricultural production of the following composition (in terms of dry matter): 55.8% carbohydrates (cellulose, hemicellulose, inulin, pectin substances), 10% proteins, 18.1% nitrogen-free extractive substances 14.3% mineral substances and 1.8% fats [Ryazanova T.V. 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 from the outer layer and crushed.

The invention is carried out as follows.

Example 1.

10 g of sawdust was immersed in a beaker with 100 ml of alcoholic solution epiphlorgidrina (module 10) concentration of 75g / liter (containing 7.5 g ECH) and kept under heating at ⁶⁰ ° C for 40 minutes, then drained, washed with distilled water, pour an aqueous solution of diethylenetriamine with a concentration of 70 g / l under microwave irradiation with a power of 300 W at a frequency of 2.45 GHz for 20 min at a temperature of 60 ° C and a solution / sorbent module 15, washed with distilled water and dried to constant weight.

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 1 min, 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 contact with the sorbent was 0.2685 mmol / L (the degree of extraction is 82.1%).

Example 2.

10 g of cotton cellulose is immersed in a beaker with 200 ml of alcoholic epiphlorgidrina solution (module 20) the concentration of 30g / L (containing 6 g of ECH) and kept under heating at a temperature of 55 ^{° C} for 60 minutes, then drained, washed with distilled water and poured water with a solution of polyethylene polyamine, with a concentration of 50 g / l under microwave irradiation with a power of 300 W at a frequency of 2.45 GHz for 10 minutes at a temperature of 80 ° C and a solution / sorbent module 20, washed with distilled water and dried to constant weight.

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 content of Ni (II) ions in the filtrate is determined. The concentration of nickel ions in the solution after contact with the sorbent was 0.294 mmol / L (the degree of extraction is 80.4%).

Example 3.

10 g of the short flax fiber is immersed in a beaker with 150 ml of alcoholic epiphlorgidrina solution (module 15) the concentration of 60g / L (containing 9 g ECH) and kept under heating at a temperature of 63 ^{° C} for 45 minutes, then drained, washed with distilled water, is poured with an aqueous solution of polyhexamethylene guanidine hydrochloride with a concentration of 60 g / L under microwave irradiation with a power of 300 W at a frequency of 2.45 GHz for 15 min at a temperature of 70 ° C and a solution / sorbent module 15, washed with distilled water and dried to constant weight.

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 min, the solution is filtered off and the content of Zn (II) ions in the filtrate is determined. The concentration of zinc ions in the solution after contact with the sorbent was 0.297 mmol / L (the degree of extraction is 80.2%).

Example 4.

10 g of wood pulp was immersed in a beaker with 200 ml of alcoholic epiphlorgidrina solution (module 20) concentration 25 g / l (containing 9 g ECH) and kept under heating at a temperature of 65 ^{° C} for 30 minutes, then drained, washed with distilled water and poured water with a solution of polyethylene polyamine with a concentration of 100 g / l under microwave irradiation with a power of 300 W at a frequency of 2.45 GHz for 18 min at a temperature of 50 ° C and a solution / sorbent module 10, washed with distilled water and dried to constant weight.

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 10 min, the solution is filtered off and the content of Cd (II) ions in the filtrate is determined. The concentration of cadmium ions in the solution after contact with the sorbent was 0.2925 mmol / L (the degree of extraction of Cd (II) ions is 80.5%).

Example 5.

10 g of crushed stalks artichoke immersed in a beaker with 150 ml of alcoholic epiphlorgidrina solution (module 15) the concentration of 50g / L (containing 9 g ECH) and kept under heating at a temperature of 58 ^{° C} for 55 minutes, then drained, washed with distilled water, is poured with an aqueous solution of polyhexamethylene guanidine hydrochloride with a concentration of 80 g / L under microwave irradiation with a power of 300 W at a frequency of 2.45 GHz for 30 min at a temperature of 30 ° C and a solution / sorbent module 10, washed with distilled water and dried to constant weight.

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 is filtered off and the content of metal ions in the filtrate is determined. The concentration of Cu (II), Ni (II), Zn (II) and Cd (II) ions in the solution after contact with the sorbent was 0.3225; 0.336; 0.3315 and 0.339 mmol / L, respectively (recovery rates 78.5; 77.6; 77.9 and 73.4%).

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 you to achieve the claimed technical result, namely: increase the degree of extraction of heavy metal ions by 2-5% and reduce the temperature during microwave irradiation (microwave treatment) of sorbents from 150-200 ° C to 30 -80 ° C.

Table

EXAMPLES Power
extraction,% Processing temperature, ° С Cu ²⁺ Ni ²⁺ Zn ²⁺ Cd ²⁺ 1. 82.1 - - - 60 2. - 80.4 - - 80 3. - - 80.2 - 70 4. - - - 80.5 50 five. 78.5 77.6 77.9 73.4 thirty PROTOTYPE 77.9 - - - 150 - 75.9 - - 200 - - 74.3 - 180 - - - 73.1 170 75.9 74.1 73.3 71.7 160

Claims (1)

A method for extracting heavy metal ions from aqueous solutions by contacting them at room temperature at a solution pH of 3-7 for 1-20 min with cellulose-based polymer sorbents modified by microwave irradiation with a power of 300 W at a frequency of 2.45 GHz, characterized in that that the modification of sorbents is carried out by their preliminary treatment in an alcoholic solution of epichlorohydrin with a concentration of 25-75 g / l at a temperature of 55-65 ° C for 30-60 minutes and a solution / sorbent module 10-20 followed by pressing, washing with distilled water and processing in an aqueous solution of diethylenetriamine, or polyethylenepolyamine, or polyhexamethyleneguanidine hydrochloride with a concentration of 50-100 g / L under microwave irradiation for 10-30 minutes at a temperature of 30-80 ° C and a solution / sorbent module 10-20, rinsing with distilled water and drying until constant weight.