RU2331470C2 - Method of obtaining composition for cleaning and disinfection of water - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of obtaining the polymeric composition is proposed. It is obtained by inter-reacting a guanidine containing polymer and a natural mineral in which interaction of the water-soluble guanidine containing polymer and a natural mineral is accomplished by intercalation of the guanidine containing monomer in the interlayer space of montmorillonite and its subsequent polymerisation. The relation of components in the obtained composition is, mass%: montmorillonite 50-85, methacrylate of guanidine 15-50.

EFFECT: invention makes it possible to increase the sorption activity of the composition.

3 ex, 4 tbl

Description

The invention relates to the field of production of composite materials with sorption and biocidal properties and intended for the purification and disinfection of water.

It is known that the use of polymer derivatives of guanidine for disinfecting water is equivalent to ozonation or chlorination in efficiency, however, unlike the latter, it does not irritate the mucous membranes and skin, is not accompanied by the accumulation of carcinogenic substances in water, and does not cause allergic reactions in humans and corrosion equipment [K.E. Skvortsova, A.G. Nekhorosheva, P.A. Gembitsky, In coll. Problems of disinfection and sterilization (Edited by V.I. Vashkov). Issue 24. VNIIDiS, Moscow, 1975. P.58].

The most famous and studied analogue of the polymer used to obtain the composition is polyhexamethylene guanidine (PHMG), which is a high molecular weight derivative of a specific nitrogen base - guanidine

[P.A. Gembitsky, L.F. Boksha, G.F. Boldenkov, S.I. Murmylo, D.S. Zhuk. Chemical industry, No. 2, 82 (1984)].

Due to the combination of flocculating and biocidal properties, polyhexamethylene guanidine-based polymeric materials are used in the treatment and disinfection of domestic and industrial wastewater [V.I. Zotova, M.I. Afanasyeva, N.Yu. Tishkova, P.A. Gembitsky, I.I. Vointseva. Questions of balneology, physiotherapy and exercise therapy. No. 2, 48 (1992)].

Closest to the proposed invention is a method for producing a biocidal sorbent of clinocide, which is a natural zeolite (clinoptilolite-containing tuff), on the surface of which PHMG is fixed with epichlorohydrin [V.A. Nikashina, P.A. Gembitsky, E.M. Katz, L. F. Boksha, A.Kh. Galuzinskaya. Izv. AN Ser.chem., 1550 (1994)].

The method of its preparation consists in the fact that for the fastening of PHMG in a water-insoluble form on a zeolite, a cross-linking reaction of PHMG using epichlorohydrin in the presence of alkali is used (0.7-1.5 mol of epichlorohydrin per PHMG unit). The reaction occurs by the mechanism of sequential oxyalkylation of guanidine groups. Clinocide is a sorbent in relation to ions of heavy and radioactive metals. Clinocide has a cation exchange capacity (1.0-1.5 mEq. / Ml), anion exchange capacity (0.2-0.3 mEq. / Ml) and biocidal properties [US Pat. 2050971, Russian Federation; B. I. (36), 88 (1995)].

The disadvantages of the method of obtaining the specified composition are the need to use epichlorohydrin to crosslink the guanidine-containing polymer and fix it on the surface of the zeolite, the additional consumption of alkali, multi-stage and duration of the process. The disadvantage of the polymer composition is the low ion-exchange capacity, since only the surface of the composition modified by organic matter has sorption properties.

The tasks solved by the invention:

- increasing sorption activity and simplifying the technology of sorbents for the purification and disinfection of water;

- improving the performance of bentonite clay as a sorbent, i.e. giving a structure that allows you to use it in a dynamic mode of water treatment;

- reducing the cost of polymer composite materials through the use of natural materials as raw materials;

- expanding the possibilities of using sorbents for the extraction of wide spectrum impurities from water (inorganic impurities, organic substances, ions, dyes, etc.).

The invention is characterized in that to obtain a biocidal sorbent, a layered mineral (montmorillonite) and a guanidine-containing polymer intercalated into the interlayer space of a clay mineral are used. A monomer salt based on methacrylic acid and guanidine of the formula is added as a modifier and water repellent to an aqueous suspension of bentonite clay, which contains at least 70% of the mineral of the montmorillonite group

where R = CH ₃ .

In this case, hydrophobization and surface modification of the clay mineral occurs with the formation of a layered columnar clay material. Then, a radical initiator, ammonium persulfate, is added to the aqueous solution of bentonite modified in this way, so that the total content of ammonium persulfate in the suspension is 0.05-0.2 wt.%, And the mixture is stirred for 30 minutes at a temperature of 60-70 ° C. The ratio of guanidine compound and bentonite clay (50-85) :( 15-50), preferably 75:25 wt.%. As a result, the monomer polymerizes on the surface and in the interlayer space of clay. In the course of the monomer polymerization reaction in clay, a composition is formed which is a solid homogeneous mass that can swell in water and has the properties of an effective filter material, including under dynamic conditions of water purification. The ion-exchange properties of the composition are determined both by the properties of the polymer - polyampholyte, and by the cation-exchange properties of bentonite clay. This composition is a sorbent not only in relation to heavy metal ions, but also capable of sorbing various organic pollutants such as phenol, dyes, etc. At the same time, disinfection of water occurs.

The method is as follows.

Example 1. In a four-necked flask with a volume of 0.5 l, equipped with a stirrer, reflux condenser, thermometer, 100 ml of distilled water, 5 g of montmorillonite are placed and stirred until a homogeneous suspension is obtained. Then, 2.5 g of guanidine methacrylate, 1 ml of a freshly prepared solution of ammonium persulfate containing 0.12 g of (NH ₄ ) ₂ S ₂ O ₈ are added to the suspension, and the temperature in the reaction medium is raised to 60-70 ° C. The reaction mixture is stirred until a solid homogeneous mass is formed. The resulting product was removed from the flask, washed repeatedly with distilled water and dried at room temperature for 48 hours.

Example 2. In a four-necked flask with a volume of 0.5 l, equipped with a stirrer, reflux condenser, thermometer, 100 ml of distilled water, 5 g of montmorillonite are placed and stirred until a homogeneous suspension is obtained. Then, 1.25 g of guanidine methacrylate, 1 ml of a freshly prepared solution of ammonium persulfate containing 0.12 g of (NH ₄ ) ₂ S ₂ O ₈ are added to the suspension, and the temperature in the reaction medium is raised to 60-70 ° C. The reaction mixture is stirred until a solid homogeneous mass is formed. The resulting product was removed from the flask, washed repeatedly with distilled water and dried at room temperature for 48 hours.

Example 3. In a four-necked flask with a volume of 0.5 l, equipped with a stirrer, reflux condenser, thermometer, 100 ml of distilled water, 5 g of montmorillonite are placed and stirred until a homogeneous suspension is obtained. Then, 0.75 g of guanidine methacrylate, 1 ml of a freshly prepared solution of ammonium persulfate containing 0.12 g of (NH ₄ ) ₂ S ₂ O _{8 is} added to the suspension, and the temperature in the reaction medium is raised to 60-70 ° C. The reaction mixture is stirred until a solid homogeneous mass is formed. The resulting product was removed from the flask, washed repeatedly with distilled water and dried at room temperature for 48 hours.

The use of guanidine-containing monomer capable of further polymerization as a water repellent and modifier in the interlayer space of the clay of the claimed invention greatly simplifies the method of obtaining a polymer composition and reduces the duration of the process.

The technical result of the invention is expressed in improving the quality of biocidal sorbents based on natural materials and polymers, reducing the consumption of expensive reagents, increasing consumer properties, there is no need to create special devices for cleaning and disinfecting water.

The possibility of extracting certain heavy metals from wastewater and natural waters by synthesized polymer composites was investigated using model solutions. The mass concentration of metals in water samples was measured before and after treatment with composites by the atomic adsorption method with electrothermal atomization using the MGA-915 atomic absorption spectrometer. The research results are shown in table 1.

Table 1 No. element Metal concentration, mg / l stock solution after the introduction of the sorbent The degree of sorption,% polymer composition one copper (II) 2.91 0,047 98.3 2 lead (II) 1.38 0.192 86.08 3 cadmium (II) 1.84 0.205 88.85

As can be seen from the table, the synthesized guanidine-containing composite materials exhibit a fairly high sorption activity in relation to the studied metals.

The results of the study of sorption activity for iodine and methylene blue are presented in table 2.

table 2 No. Detectable substance The initial mass of the substance
mg The final mass of the substance, mg The specific activity of the sorbent, g / 100 g one methylene 3 0.0125 2.98 blue 2 iodine 254 210 44,45

Preliminary studies of the bactericidal activity of the synthesized composite materials, conducted in conjunction with the Bacteriological Laboratory of the GSEN CBD, showed that they are very active and have a biocidal effect in relation to gram-positive and gram-negative microorganisms.

Table 3
The dependence of the number of colonies of Escherichia coli on the concentration of the sample S, g / l 0,0003 0.003 0,03 0.3 3 sample The number of colonies thirty 28 23 fifteen 12 polymer composition 54 42 36 29th 23 PHMG

The diameter of the zone of growth inhibition of microorganisms
Table 4 Sample The diameter of the zone of growth inhibition (mm) Qualitative assessment of biocide Polymer composition fifteen +++ PHMG eleven ++

Thus, the present invention provides for the production of guanidine-containing polymer-clay compositions for the purification and disinfection of natural and wastewater with the necessary sorption properties, using cheap and affordable raw materials - bentonite clay.

Claims (1)

A method of obtaining a composition for purifying and disinfecting water, comprising modifying a natural mineral with a guanidine-containing polymer, characterized in that bentonite clay containing at least 70% of the montmorillonite group mineral is taken as a natural mineral, to the aqueous suspension of which a monomeric salt based on methacrylic acid and guanidine is added in the amount of 15-50% by weight of montmorillonite, and a radical initiator of polymerization, carry out stirring at 60-70 ° until the monomer polymerizes on the surface and clay layer space.