RU2129913C1 - Filter for cleaning gas-air mixtures and purification of potable and sewage waters - Google Patents

Abstract

FIELD: cleaning of gases and purification of potable and sewage waters. SUBSTANCE: filter is based on granulated synthetic or natural zeolite with particles sizing 0.1-1.5 mm. Zeolite is impregnated with organosilicon compound N,N′-bis(3-triethoxysilylpropyl)- thiocarbamide. Composition of zeolite with organosilicon compound increases absorbing ability of the filter with respect to toxic and carcinogenic compounds contained in gas-air mixtures, potable and sewage waters. Filter produces protective effect on humoral immunity and also on protein and nucleotide metabolism due to absorption of the most part of toxicants and cancerogenic substances from gas-air mixtures and waters. EFFECT: higher efficiency. 10 tbl

Description

 The present invention relates to the field of purification of gas-air mixtures and water from toxic and carcinogenic substances and can be used for purification of exhaust gases from industrial enterprises (chemical enterprises, thermal power plants), exhaust gases, purification of drinking and wastewater, as well as in food industry enterprises for purification drinks, juices, wines, etc.

 Currently known filters for purification of exhaust gases of industrial enterprises are based on the method of catalytic conversion of toxic and carcinogenic substances into less harmful and non-toxic ones. Among the effective catalysts include a variety of substances - from minerals used without any pre-treatment, and simple metals to complex compounds of a given composition and structure. Usually, catalytic activity is shown by solids with an ionic or metallic bond, which have strong interatomic fields (1), the active components of the catalysts can be divided into three groups: noble metals, alloys, and oxide systems.

 To neutralize gaseous media in various industries, metals of the platinum group or other noble metals are used, which is due to the ability of these metals to accelerate a variety of reactions.

 Known filters for the purification of exhaust gases of industrial enterprises from carbon monoxide and lower hydrocarbons containing platinum and rhodium (3 - 5). Cleaning the gas mixture occurs at 98 - 100% at a temperature of 275 - 450 degrees. The content of platinum and rhodium on the catalyst is 20-50%.

 A filter based on lanthanides is also known (6). The filter effectively cleans the exhaust gases from carbon monoxide, sulfur oxides and hydrogen sulfide.

 Despite the high catalytic properties of filters containing noble metals, in the process of converting toxic substances into low toxic and non-toxic, catalysts of this group tend to be replaced by less expensive catalysts.

 Known filters for cleaning exhaust and exhaust gases of industrial enterprises based on chromites, ferrites, manganates of various metals (7). These catalysts operate at high temperatures. To reduce the temperature of complete oxidation on these filters, various modifying additives are introduced into them.

Known filters, which include catalysts based on oxides and hydroxides of base metals. So, for the oxidation of carbon monoxide from carbon dioxide, a filter is used that contains as a catalyst a combination of tin dioxide and chromium dioxide in the ratio SnO ₂ : CrO ₂ = 94: 6 (8).

 A known filter for cleaning exhaust gases, in which a mixture of copper and chromium oxides is used as a catalyst in a ratio of 2: 1 (9).

 Manganese oxide and hydroxide are used in filters to bind nitrogen oxides (10).

 Filters are known that are made using salts and oxides and reduce the content of carbon monoxide, nitrogen oxides, and hydrogen cyanide in air-gas mixtures (11).

 The disadvantage of all these filters is a small range of neutralized toxicants or their high cost. The adsorption-catalytic method has a great advantage. The adsorption-catalytic method for capturing volatile organic and inorganic compounds is one of the most common in industry. It allows the purification of gases and water at the lowest cost (12). Currently, one of the cheapest and most effective filters used for these purposes are zeolite filters.

A known filter for the purification of air-gas mixtures of carbon dioxide (13), in which zeolite impregnated with MoO ₃ (5 - 8%) and Al ₂ O ₃ (45%) is used as a catalyst. The cleaning efficiency of 50% at a volumetric flow rate of 800 - 2000 l / h.

 Closest to the proposed invention are filters for the purification of gases from macromolecular substances, consisting of zeolite, modified 6 to 8 wt. %, Ni (14). A similar filter is used for wastewater treatment. It contains finely divided zeolite with a grain size of 0.45 - 1.3 mm. It is consumed in an amount of 1 cubic decimeter per 320 liters of water (15). The disadvantage of the described methods of purification of water and gas-air media is their bulkiness, a limited range of absorbed substances, in particular, absorbing low molecular weight hydrocarbons, ammonium compounds and Sr from gas-air media, they do not absorb or absorb in small quantities such carcinogenic substances as multinuclear aromatic hydrocarbons (pyrene , benz (a) pyrene, benz (g, h, i) perylene, dibenz (a, h) anthracene, etc.), nitrosamines (N-nitrosodimethylamine, N-nitrosomorpholine, N-nitrosopyrrolidine, etc.), as well as a number trace element in. In addition, the proposed cleaning methods cannot be simultaneously used both for cleaning gas-air mixtures and aqueous media.

 The problem to which the invention is directed is to increase the capture efficiency of carcinogenic and toxic substances.

 The essence of the invention lies in the fact that for the purification of air-gas mixtures and aqueous media, a granular sorbent is used, which is a granule of artificial or natural zeolites impregnated with organosilicon monomer N, N'-bis (3-triethoxysilylpropyl) -thiocarbamide, the amount of which is 10 - 15% by weight of granules. The diameter of the granules is 0.1 - 1.5 mm.

 For this purpose, zeolite granules, impregnated with a 10% solution of monomer in a solvent, preferably ethanol, and dried in air, are subjected to heat treatment at a temperature of 60 - 70 degrees for several hours. The mechanism of binding of a monomer to a carrier is based on the process of copolycondensation of monomers with surface hydroxyl groups of the carrier according to the scheme given at the end of the description.

 In this case, the zeolite chemically binds to the polysiloxane polymer, as a result of which a new adsorbent is formed, which has higher adsorption properties compared to the initial adsorbent zeolite.

 The technical result obtained by using the proposed adsorbent in filters for the purification of air-gas mixtures and water is to increase the absorption efficiency of polycyclic aromatic hydrocarbons, nitrosamines and heavy metals by increasing the adsorption properties of the filter (N, N'-bis (3-triethoxysilyl propyl adsorbent in the filter) ) -thiocarbamide is impregnated in zeolites (having high selectivity for polar molecules) without increasing the volume and weight of the filter).

 The proposed filter for the purification of gas-air mixtures and water can be performed by all known technological methods that are used for the manufacture of zeolite filters for the purification of water and exhaust gases (16, 17).

 Comparison of the adsorption properties of zeolites.

 Compare several filters made of natural zeolites, for these purposes we will use: clinoptilolite, chabazite and mordenite. The size of the zeolite granules is from 0.1 to 1.5 mm. The adsorption capacity of zeolites will be compared with the adsorption capacity of silica gel granules of the appropriate size. All media are impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) -thiocarbamide.

 Tables 1 to 9 of the examples are given at the end of the description.

 Example 1. The capture of volatile nitrosamines (ON) in air-gas mixtures with filters: 1 - a filter of silica gel, impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) thiocarbamide; 2 - chabazite impregnated with a 10% solution of N, N'-bis (3-triethoxyethyl) thiocarbamide; 3 - mordenite, impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) - thiocarbamide; 4 - clinoptilolite impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) thiocarbamide.

 Example 2. The capture of polycyclic aromatic hydrocarbons from gas mixtures.

 Example 3. The capture of polycyclic aromatic hydrocarbons from aqueous solutions of the studied filters.

 Example 4

 The efficiency of the capture of metals from an experimental gas-air mixture.

 Example 5. The efficiency of absorption of metals from water. Water was filtered through an adsorption layer of 15 cm. Bulk flow rate 70 l / h.

 Example. 6. The effect of the experimental gas-air mixture on the humoral immunity of white rats.

 To study the effect of an experimental gas-air mixture containing volatile nitrosamines, polycyclic aromatic hydrocarbons and heavy metals (the composition of which is presented in Tables 1, 2, 4 “without filter”) on the humoral immunity of Wistar rats, animals were placed in the test medium for 1 hour per day for 6 months. Rats were divided into six groups: 1 - control (untreated rats); 2 - rats which were inoculated with a gas-air mixture passing through a filter made of silica gel soaked in 10% solution of N, N'-bis (3-triethoxysilylpropyl) -thiocarbamide; 3 - rats poisoned by a gas-air mixture passing through a filter made of chabazite impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) -thiocarbamide; 4 - rats poisoned by a gas-air mixture passing through mordenite, impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) thiocarbamide; 5 - rats poisoned by a gas-air mixture passing through clinoptilolite impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) thiocarbamide; 6 - rats poisoned by an experimental gas-air mixture that did not pass through any filter.

 As can be seen from the above data, seeding of animals with an experimental gas-air mixture causes a significant decrease in the number of spleen cells and the number of AOKs. At the same time, passing this mixture through filters made of various zeolites impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) -thiocarbamide makes this mixture less toxic.

 Example 7. The effect of prolonged use of water containing polycyclic aromatic hydrocarbons and heavy metals on the humoral immunity of white rats.

 To study the effect of prolonged use of water containing polycyclic aromatic hydrocarbons and heavy metals in the amounts shown in Tables 3 and 5 “without filter”, the animals were divided into 6 groups, as in the experiment with the experimental gas-air mixture. Rats received drinking water of the test composition for 6 months.

 Long-term consumption of water containing toxic substances leads to a sharp decrease in spleen cellularity and the number of AOKs. Filtration of water through zeolite filters impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) thiocarbamide eliminates the pathological status of the body.

 The achievement of the technical result is proved by the fact that when using various zeolites impregnated with a 10% solution of N, N'-bis (3-triethoxysilylpropyl) thiocarbamide, the capture efficiency of toxic and carcinogenic compounds contained in air-gas mixtures and water is increased, and the protective effect of filters on humoral immunity.

 Example 8. The effect of prolonged seeding with an experimental gas-air mixture on the content of nucleic acids in the liver and thymus of white rats.

 The study of the biological effect of the gas-air mixture was carried out under the same conditions and on the same groups of rats as in Example 6. The choice of this test is due to the fact that changes in the nucleic exchange indicate a change in the regulation of genetic information in cells and, more generally, the functional activity of organs and tissues (Zbarsky I.B., 1989). We studied the influence of the features of the synthesis of nucleic acids / RNA and DNA / in the thymus cells / as a representative of the immune system / and the liver / organ responsible for detoxification processes in the body /.

 Homogenates were prepared from weighed tissue of the thymus and liver and RNA and DNA were determined according to the Orlov method / 1961 /.

 As can be seen from table 8, in the liver tissue of a group of rats etched with an experimental gas-air mixture, and in the group that passed through a zeolite filter, an increase in RNA level is noted, which indicates both a change in the level of nucleotide metabolism and an increase in protein synthesis in the organ.

 In thymus cells, the reaction to the effect of the air-gas mixture is recorded in the same groups of animals.

 As can be seen from table 10, seeding of animals with an experimental gas-air mixture leads to an increase in DNA content in both liver tissue and thymus tissue. The use of all studied filters prevents changes in the nucleotide composition of the liver. In thymus cells, a zeolite filter and a filter made of silica gel impregnated with N, N'-bis (3-triethoxysilylpropyl) -thiocarbamide do not protect against changes in DNA content. Only the proposed filter has a protective effect.

 Thus, the experimental gas-air mixture causes changes in protein and nucleotide metabolism, expressed in an increase in the content of RNA and DNA. Moreover, the proposed filter has a maximum protective effect.

 Example 9

 The effect of prolonged use of water containing polycyclic aromatic hydrocarbons and heavy metals on the content of nucleic acids in the liver of white rats.

 The study of the biological effect of prolonged use of water containing polycyclic aromatic hydrocarbons and heavy metals was carried out under the same conditions and in the same groups of rats as in Example 7. The determination of RNA and DNA contents was carried out by the same methods as in Example 8.

 As can be seen from table 9, long-term use by rats of water containing polycyclic aromatic hydrocarbons and heavy metals, leads to changes in the nucleotide and protein metabolism in the liver tissue. The proposed filter / 4 / and the filter prototype / 2 / prevent a change in the content of RNA in the liver, however, the filter prototype does not prevent changes in the DNA content in the liver tissue, while the proposed filter has a strong protective effect.

 The achievement of the technical result is proved by the fact that the efficiency of capturing toxic and carcinogenic compounds contained in gas-air mixtures and water is increased, and the protective effect of filters on humoral immunity, as well as nucleotide and protein exchanges in the liver tissue / main organ of xenobiotic detoxification / and cells thymus. A distinctive feature of the developed filters for gas-air media and water is the high absorption efficiency of carcinogenic volatile nitrosamines, polycyclic aromatic hydrocarbons and metals from gas-air mixtures and water.

 Literature.

 1. Sailor Yu. Sh., Noskov A.S., Chumachenko V.A. Catalytic neutralization of industrial gas wastes. - N .; Sib. Dep. 1991.

 2. Putilov A.V., Kudryavtsev S.L., Petrukhin N.V. Adsorption-catalytic methods for purification of gaseous media in chemical technology. - M .: Chemistry, 1989.

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 4. A.S. N, 287914.

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 7. Moro-Oka J., Morokawa J., J. Catal., 1967, 7, 1, 25 - 32.

 8. US. Pat. N, 4.908.192.

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 12. Dubalskaya E.N. Flue gas cleaning. Environmental protection and rational use of natural resources. Vol. 14 - M .; 1990.

 13. RF patent N 2026719.

 14. A.S. N, 1818138.

 15. Sofia Zeolite Meeting '95. International Simposium and Exhibition on natural zeolites. Sofia, Bulgaria, June, 16 - 25, 1995, 25.

 16. Tarasevich Yu.I. Natural adsorbents in the process of water purification. - Kiev. : Science. Dumka. 1981, 1-207.

 17. Vaughan D.E.W. Properties of natural zeolites. Natural zeolites, occurrence, properties, use, 1976. 353 - 371.

Claims (1)

 Filter for the purification of air-gas mixtures, drinking and wastewater, representing granules of artificial or natural zeolites, characterized in that the organosilicon monomer N, N'-bis (3-triethoxysilylpropyl) -thiocarbamide is impregnated into the zeolite granules, while the amount of monomer is up to 15 % of the weight of the granules.

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