RU2143316C1 - Aluminum compounds-based sorbent - Google Patents

Abstract

FIELD: sorbents. SUBSTANCE: sorbent contains, wt %: hydrolyzed coarse aluminosilicates with particle diameter above 1 mcm, 45-70; hydrolyzed fine aluminosilicates with particle diameter 0.1-1 mcm, 10-40; hydrolyzed colloid-size aluminosilicates with particle diameter below 0.1 mcm, 3-10; and molecular-size silicon, aluminum, iron, titanium, calcium, and magnesium hydroxides, 1-10. EFFECT: extended application area and increased capacity. 5 ex

Description

 The invention relates to the field of sorption materials and can be used to purify waters contaminated with heavy metals, oil and oil products, bacterial cells and other substances.

0,02-0,08 см³/г и объем пор радиусом 1000-10000

0,05 -0,10 см³/г, см. патент Российской Федерации N 2026734 по кл. В 01 J 20/08.Known sorbents based on aluminum compounds, in particular alumina, used for cleaning aqueous solutions of organic compounds and bacterial cells, containing 3 to 12 wt. % carbon; aluminum oxide consisting of at least 50% of the χ -like phase and having a specific surface area of 90–180 mg / g and a pore volume of 100–1000 radius is contained as a sorbing matrix

0.02-0.08 cm ³ / g and pore volume with a radius of 1000-10000

0.05-0.10 cm ³ / g, see patent of the Russian Federation N 2026734 according to class. B 01 J 20/08.

The disadvantage of this sorbent is the low adsorption capacity due to the limited specific surface area. In addition, its adsorption capacity is highly dependent on the type of adsorbed contaminant (41–95% for vitamin B ₁₂ and 63–73% for staphylococcus and E. coli). For the purification of contaminated water from heavy metals and oil products, this sorbent is not effective. In addition, it has a very high cost.

0,005 - 0,1 см³/г и объем радиусом 100 - 1000

0,008 - 0,25 см³/г, при этом модифицирующий углерод распределен равномерно по диаметру зерна сорбента и расположен в виде псевдографитовых кристаллитов как между агрегатами частиц оксида алюминия, так и внутри этих агрегатов, см., например, патент Российской Федерации N 20266733 по кл. В 01 J 20/08.Also known is a sorbent based on aluminum compounds; carbon oxide modified alumina is contained as a sorbent matrix; It is used to clean aqueous solutions of organic compounds and bacterial cells and contains micro-, meso- and macropores; the sorbent has a true density of 2.90 - 3.15 g / cm ³ , specific surface area 150 - 350 mg / g, attrition loss 0.1 - 0.5% / min, pore volume with a radius of 1000 - 10000

0.005 - 0.1 cm ³ / g and a volume of radius 100 - 1000

0.008 - 0.25 cm ³ / g, while the modifying carbon is evenly distributed over the grain diameter of the sorbent and is located in the form of pseudo-graphite crystallites both between aggregates of aluminum oxide particles and inside these aggregates, see, for example, patent of the Russian Federation N 20266733 class B 01 J 20/08.

 This sorbent has a slightly larger specific surface area, however, like all sorbents of contact action, it is fully characterized by the disadvantages of the technical solution described above: low adsorption ability, high degree of dependence on the type of sorbed pollutant, high cost, complexity of preparation due to the need for an extremely high degree homogenization of the composition.

 Also known is a sorbent based on natural aluminosilicate raw materials used for the purification of aqueous solutions, containing zeolites and impurity minerals such as quartz, feldspars, mica, see Russian Federation patent N 2035994 for cl. B 01 J 20/16.

 This sorbent, taken as a prototype of the present invention, also allows only contact sorption, which leads to its low adsorption capacity, significantly depending on the type of sorbed pollutant; removal of toxic substances from the sorbent according to patent N 2035994 is carried out by washing, which causes leaching of the most active components of colloidal dispersed and molecularly dispersed; sorbent has a high cost.

 The present invention is based on the solution of the problem of creating a sorbent based on aluminum compounds, for example aluminosilicates, which would have high adsorption capacity, reduced dependence on the type of sorbed pollutant and low cost.

According to the invention, the sorbent based on natural aluminosilicate raw materials used for the purification of aqueous solutions, contains, wt.%:
Hydrolyzed coarse aluminosilicates with a particle diameter of more than 1 μm - 45 - 70
Hydrolyzed fine aluminosilicates with a particle diameter of 0.1 - 1 μm - 10 - 40
Hydrolyzed colloidal dispersed aluminosilicates with a particle diameter of less than 0.1 microns - 3 - 10
Molecularly dispersed hydroxides of silicon, aluminum, iron, titanium, calcium and magnesium - 1 - 10
In this regard, according to the applicant, it can be concluded that the invention meets the criterion of "novelty." The implementation of the distinguishing features of the invention (in combination with the characteristics given in the restrictive part of the claims) leads to the appearance of fundamentally new properties in the object, which include the implementation of complex sorption: contact (surface) and cross-solution. Coarse and finely dispersed particles adsorb pollutants topochemically, and colloidal dispersed aluminosilicates and molecularly dispersed hydroxides determine the processes of cross-solution chemisorption, in which the "specific surface" of the sorbent is extremely large. The concept of "specific surface" of the sorbent in this case is conditional, because sorption occurs at the colloidal molecular level of the sorbent substance. Due to this, the adsorption capacity of the sorbent increases by several orders of magnitude in comparison with sorbents of only contact action.

 Complex sorption (both topochemical and cross-solution) provides a radical decrease in the dependence of the efficiency of the adsorption process on the type of pollutant.

 The low cost of the sorbent is due to the use of natural mineral raw materials.

 The applicant has not revealed any information about the influence of the differences of the invention on the achieved technical result. This allows us to conclude that the claimed technical solution meets the criterion of "inventive step".

 The proposed material is obtained by sequential processing of natural aluminosilicate rocks with acid and alkaline reagents.

 In particular, Cambrian clay (deposits of the Leningrad region) was used, containing clay particles (<0.001 mm) 35.7%, with a ductility number of 23.5.

The clay composition includes, wt.%: SiO ₂ - 65.43; Al ₂ O ₃ - 17.32; Fe ₂ O ₃ - 4.23; CaO -1.91; MgO - 2.27; TiO ₂ 0.67; SO ₃ - 0.08; Na ₂ O - 0.67; Ka ₂ O - 3.11; nnn - 4.31. The carbonate content is less than 2%. The sorbent from clay was prepared in the form of a viscous-plastic paste, for which 8 wt.% Concentrated sulfuric acid was added to the clay mass with its moisture content of 25-30%. The dry clay content is 92 wt.%. The uniformly mixed acid-clay mass was maintained at normal temperature and pressure for 3-4 hours, which provided deep acid hydrolysis of aluminosilicates during a pH of ≤2.

 Then, after acid activation, the paste was neutralized and alkaline hydrolyzed with lime additives (10-15 wt.%) To bring the pH to 12-14 with an additional increase in paste moisture to 60 - 70%. After keeping the viscoplastic paste for 4 - 5 hours at normal temperature and adding an aluminosilicate sorbent was used to purify contaminated water.

 Due to the intensive hydrolysis of the mineral components of the feed, a complex mineral sorbing matrix with a wide dispersion range is formed.

 The adsorption capacity of the proposed material was determined by the following method. A weighed portion of the sorbent in a paste-like state was introduced into a 200 ml flask in the ratios t / f (solid / liquid) = 1: 100: 1: 200. As model solutions, solutions of various pollutants in distilled water were used. A portion of the sorbent was mixed with the solution for 1 min. To obtain a uniform suspension and kept for 1:24 hours, depending on the type of contaminant. The residual content of pollutants in the filtered clarified water was determined using an atomic adsorption spectrophotometer.

Sorbent contained:
Example 1

The sorbent contained, wt.%:
Coarse Aluminosilicates - 30.0
Fine aluminum silicates - 55.0
Colloidal dispersed aluminosilicates - 12.5
Aluminum hydroxide - 0.9
Iron hydroxide - 0.3
Silicon hydroxide - 0.7
Titanium hydroxide - 0.1
Calcium hydroxide - 0.3
Magnesium Hydroxide - 0.2
The dry matter content of the sorbent to the contaminated liquid was 1: 100.

The concentration of pollutants in the model solution, mg / l:
Cu - 9.87
Zn - 10.80
Cd - 5.39
Ni - 11.55
Cr ⁺³ - 4.55
Solution pH - 3.9
The interaction time of the sorbent with the solution is 24 hours.

где I_ad - степень очистки (величина адсорбции);
Σ M_{ei исх.} - суммарная концентрация загрязнителей в исходном растворе, мг/л;
Σ M_{ei ост.} - суммарная концентрация загрязнителей в очищенном растворе, мг/л.The residual content of pollutants after application of the sorbent, mg / l:
Cu - 0.01
Zn - 0.005
Cd - 0.02
Ni - 0.02
C ⁺³ - 0.02
The degree of purification was determined from a known ratio:

where I _ad is the degree of purification (adsorption value);
Σ M _{ei ref.} - total concentration of pollutants in the initial solution, mg / l;
Σ M _{ei stop} - total concentration of pollutants in the purified solution, mg / l.

I _ad1 = [(42.26 - 0.075) / 42.26] = 99.9%.

 Example 2

Sorbent contained:
Coarse Aluminosilicates - 58.0
Fine aluminum silicates - 30.5
Colloidal dispersed aluminosilicates - 2.0
Aluminum hydroxide - 2.6
Iron hydroxide - 2.2
Silicon Hydroxide - 3.3
Titanium hydroxide - 0.4
Calcium hydroxide - 0.6
Magnesium Hydroxide - 0.4
The ratio of dry matter of the sorbent to the contaminated liquid was 1: 100.

The concentration of pollutants in the model solution, mg / l:
Cu - 10.27
Zn - 9.90
Cd - 4.29
Ni - 12.57
Cr ⁺³ - 6.51
Solution pH - 4.5
The interaction time of the sorbent with the solution is 1 hour.

The residual content of pollutants, mg / l:
Cu - 0.71
Zn - 0.96
Cd - 0.25
Ni - 0.93
Cr ⁺³ - 0.56
The degree of purification I _ad2 = 92.2%
Example 3

The sorbent contained, wt.%:
Coarse Aluminosilicates - 37.8
Fine Aluminosilicates - 45.0
Colloidal dispersed aluminosilicates - 7.5
Aluminum hydroxide - 2.3
Iron hydroxide - 2.2
Silicon Hydroxide - 3.5
Titanium hydroxide - 0.5
Calcium hydroxide - 0.9
Magnesium Hydroxide - 0.3
The ratio of dry matter of the sorbent to the contaminated liquid was 1: 200.

The concentration of pollutants in the model solution, mg / l:
Cu - 8.71
Zn - 12.21
Pb - 4.34
Co - 2.72
Sr - 1.75
Cr ⁺³ - 6.74
Solution pH - 4.8
The interaction time of the sorbent with the solution is 12 hours.

The residual content of pollutants, mg / l:
Cu - 0.15
Zn - 0.92
Pb - 0.01
Co - 0.03
Sr - 0.01
Cr ⁺³ - 0.17
The degree of purification I _ad3 = 96.4%
Example 4

The sorbent contained, wt.%:
Coarse Aluminosilicates - 47.0
Fine aluminum silicates - 39.0
Colloidal dispersed aluminosilicates - 7.6
Aluminum hydroxide - 1.9
Iron hydroxide - 0.8
Silicon Hydroxide - 2.2
Titanium hydroxide - 0.4
Calcium hydroxide - 0.7
Magnesium Hydroxide - 0.4
The ratio of dry matter of the sorbent to the contaminated liquid was 1: 150.

The concentration of pollutants in water, mg / l:
Crude oil - 57.0
Fuel oil - 12.1
Mineral oil - 5.7
Surfactants - 2.6
Solution pH - 6.7
The interaction time of the sorbent with contaminated liquid is 1 hour.

The residual content of pollutants, mg / l:
Crude oil - 0.05
Fuel oil - 0.01
Mineral oil - 0.06
Surfactants - 0.01
The degree of purification I _ad4 = 98.5%
Example 5

The sorbent contained, wt.%:
Coarse aluminosilicates - 35.7
Fine aluminum silicates - 50.2
Colloidal dispersed aluminosilicates - 8.7
Aluminum hydroxide - 2.1
Iron hydroxide - 0.7
Silicon Hydroxide - 1.6
Titanium hydroxide - 0.2
Calcium hydroxide - 0.7
Magnesium Hydroxide - 0.1
The ratio of dry matter of the sorbent to the contaminated liquid was 1: 100.

The concentration of pollutants in water:
Dried E. coli culture - 200 mg / l
Solution pH - 6.9
The interaction time of the sorbent with the solution is 20 hours.

Residual Contaminant Content:
Dried E. coli culture - 2.4 mg / l.

The degree of purification: I _ad5 = 98.8%.

 As can be seen from the above examples, the proposed sorbent has a very high adsorption capacity, which relatively little depends on the type of adsorbed pollutant. For the manufacture of the sorbent, common and relatively inexpensive natural materials, non-deficient reagents and standard equipment are used.

 These circumstances allow us to conclude that the invention meets the criterion of "industrial applicability".

Claims (1)

Sorbent based on natural aluminosilicate raw materials used for the purification of aqueous solutions, characterized in that it contains, wt.%:
Hydrolyzed coarse aluminosilicates with a particle diameter of more than 1 μm - 45 - 70
Hydrolyzed fine aluminosilicates with a particle diameter of 0.1 - 1 μm - 10 - 40
Hydrolyzed colloidal dispersed aluminosilicates with a particle diameter of less than 0.1 microns - 3 - 10
Molecularly dispersed hydroxides of silicon, aluminum, iron, titanium, calcium and magnesium - 1 - 10