Mineral-carbon Sorbents Research Articles

ТЕРМОДИНАМИЧЕСКИЙ АНАЛИЗ ОКИСЛИТЕЛЬНО – ВОССТАНОВИТЕЛЬНЫХ РЕАКЦИЙ, ПРОТЕКАЮЩИХ ПРИ ГАЛЬВАНОКОАГУЛЯЦИОННОЙ ОЧИСТКЕ СТОКОВ

Abstract. One of the most important environmental problems is the purification of industrial wastewater from heavy metal ions. Various methods are used to solve this problem: chemical, physico-chemical, sorption, but the most promising method for cleaning industrial wastewater containing heavy metal ions, namely copper, nickel and zinc, is the galvanocoagulation method. However, the literature does not sufficiently cover the processes of cementation of heavy metals on cathode loading. A physico-chemical approach to this process is necessary to confirm the process of separation of heavy metal ions from wastewater in the form of sediment and the creation of new industrial wastewater treatment schemes. The composition of the loading is essential in galvanocoagulation neutralization, therefore, in order to determine the effect of the type of active loading, a carbon mineral sorbent (SGN) obtained from ores of cryptocrystalline graphite (Noginsky deposit of the Krasnoyarsk Territory) was used. The studies were carried out in a galvanocoagulation module by passing wastewater through a loading consisting of a mixture of iron shavings and granules of carbon mineral sorbent based on ores of cryptocrystalline graphite (SGN). At the same time, the air dispersed in the lower part of the device was bubbled through the loading. As a result of the operation of the Fe-SGN short-circuited galvanic cell, iron scrap was dissolved and its intensive oxidation to Fe3+ by air oxygen. The article considers the mechanism of galvanocoagulation neutralization of wastewater based on thermodynamic analysis of redox reactions occurring during galvanocoagulation wastewater treatment.
 Subject of the study: both model and real wastewater from the production of electroplating coatings containing copper, zinc and nickel ions with the following concentrations were used: =60 mg/dm3; =15 mg/dm3; =20 mg/dm3
 Materials and methods: galvanocoagulation neutralization using a short-circuited Fe-SGN galvanic cell (carbon mineral sorbent)
 Results: the physico-chemical patterns of the galvanocoagulation process of wastewater treatment have been studied and the thermodynamic parameters of heavy metal ion reduction reactions have been determined
 Conclusions. It has been experimentally established that it is possible to intensify the process of galvanocoagulation of wastewater containing heavy metal ions by using a carbon mineral sorbent as a cathode loading, which reduces the processing time with a high purification effect and a difficult-to-dissolve precipitate is formed.

New Carbon-Mineral Sorbent Based on Aluminum Oxide, Polydimethylsiloxane, and Single-Wall Carbon Nanotubes: Assessment of the Effect on Erythrocytes In Vitro.

A comparative study of the effect of a sorbent with nanotubes (Al2O3@ WCNT-PDMS) and a carbon-mineral sorbent (Al2O3@C) on the parameters of human erythrocytes was carried out. Using scanning flow cytometry, the morphological and functional parameters of venous blood erythrocytes as well as drainage blood after its perfusion through columns with sorbents were determined. The compared samples Al2O3@SWCNT-PDMS and Al2O3@C are similar by their effect on the morphological and functional parameters of erythrocytes. The maximum membrane extensibility increased to a greatest extent after contact with Al2O3@C, the amount of hemoglobin in erythrocytes decreased to the greatest extent after perfusion through a column with Al2O3@SWCNT-PDMS sorbent. The scanning flow cytometry is promising for assessing the effect on erythrocytes of new sorption materials intended for blood detoxification. Changes in the parameters of erythrocytes of blood collected in a sterile drainage system for subsequent reinfusion were revealed.

Research of Mixed Carbon Sorbents for Removal of Oil Products from Water and Soil for Preservation of Environmental Infrastructure

The article presents the results of studies on the study of technologies for obtaining carbon sorbents from by-products of agriculture, woodworking industry and utilities under the influence of low-temperature one-stage carbonization, as well as structural, physicochemical, absorbing properties of mixed carbon-carbon and carbon-mineral sorbents and their effectiveness and economic feasibility in removing petroleum products from the environment and preserving its infrastructure. Oil consumption and absorption capacity of petroleum products of the mixture of pine sawdust carbonate: expanded graphite, at a ratio of 50:50%, 2.5-3.0 times higher than the sawdust carbonate. Its use is the most promising and cost-effective in removing petroleum products from the environment and preserving environmental infrastructure. The obtained data on influence of the qualitative composition of mixed materials on their sorption capacity in relation to oil and oil products allow us to suggest the feasibility of using carbon-carbon materials as effective sorbents of oil products from water and soil, and carbon-mineral, for example, as effective barriers to preventing the migration of oil and petroleum products into groundwater. Carbon-carbon materials should be used as effective sorbents to remove petroleum products from the water surface and soil, and carbon-mineral as effective barriers to prevent the migration of oil and petroleum products into groundwater.

Possibility of application of naphthalene as carbon pyrolysate to obtain mineral-carbon sorbents

Physicochemical properties of mineral-carbon sorbents obtained by thermal decomposition of a mixture of aluminum hydroxide or alumina and naphthalene were investigated. Depending on the amount of pre-filled organic substance (naphthalene), sorption capacity, degree of porosity, surface character (hydrophilic–hydrophobic properties) and mesopores surface were tested. Properties of the obtained sorbents were tested by adsorption methods such as low-temperature nitrogen adsorption, adsorption of benzene vapors and thermal analysis methods (TG, DTG). Thermoporosimetric tests were also performed using DSC calorimeter. Investigations of water freezing and melting were carried out in the temperature range from − 40 to + 20 °C. When analyzing the curves of the distribution pore volume with respect to the effective radii for benzene vapors adsorption, it was found that for samples obtained using aluminum hydroxide as a mineral matrix and for aluminum hydroxide itself, the monodispersive distribution of mesopores volume was observed. The above observations were confirmed on the basis of thermoporosimetric tests. Only in the case of pure aluminum hydroxide, different results were obtained.

Perspectives for use of technological waste to obtain carbon-mineral sorbents

Carbon-mineral materials were obtained by mixing of clay mineral (montmorillonite) with aqueous solutions of cationic dye “methylene blue” and anionic dye “direct clean-blue” (a component of wastewater of dyeing enterprises) and subsequent drying and carbonization in an atmosphere of water vapor. It is shown that the specific surface area of the synthesized carbon materials depends on the nature of the modifying organic compound, its content in the sample and the influence of ultrasound. It is found that the preliminary activation of the initial clay increases the surface area, but does not have a significant effect on the adsorption of phenol, compared with materials obtained without activation. Hydrophobic surface properties of materials are confirmed by the results of studies on the adsorption of phenol from aqueous solutions. Adsorption capacity of obtained carbon-mineral materials with respect to phenol is 4-8.5 mg · g−1, which is 15-30 times higher than that of the original clay. Synthesized sorbents are comparable to the adsorption capacity with respect to phenol with carbon material obtained by direct pyrolysis.

Carbon-Mineral Adsorbent from Petroleum Pitch and Precipitated Colloidal Silica

The carbon-mineral adsorbent was prepared according to a two-stage scheme, which, despite the hydrophilic nature of the surface of colloidal silica, made it possible to prepare pellets with a high specific surface area and compressive strength of up to 70 m2/g and 8 MPa, respectively. The proposed method consists in mixing petroleum pitch and colloidal silica in the first stage, followed by granulation and carbonization (at 1000 °C); the resulting carbon-mineral material is crushed and mixed with petroleum pitch in the second stage, after which it is also granulated and carbonized (at 700 °C). Based on the obtained carbon-mineral sorbent, a highly porous carbon adsorbent is produced by etching the silicate base in a concentrated solution of sodium hydroxide during boiling. The total pore volume of the obtained samples reached 3.5 cm3/g.

Preparation and Characterization of Carbon-Mineral Sorbents Based on Sapropel from Novgorod Oblast. Part 2

The sorption capacity of carbon-mineral sorbents for Cu(II) ions, methyl orange, and iodine was studied. The optimal carbonization temperature for 100:5, 100:10, and 100:20 mixtures was 600°C, which agreed with experimental IR spectroscopic, elemental analytical, and modern thermal analytical data for carbonized sapropel—bentonite-clay mixtures. The carbon-mineral sorbent prepared by carbonization of 100:5 sapropel—bentonite-clay mixture showed high maximum adsorption for Cu(II) ions, methyl orange, and iodine. The volumes of meso- and micropores of all studied sorbents were determined using molecular probes. Carbon-mineral sorbents prepared by carbonization of sapropel—bentonite-clay mixtures at 600°C in an oxidizing medium were found to be meso-macroporous.

Preparation and Study of Carbon-Mineral Sorbents Based on Novogorod Sapropel. Part 1

Preparation and Study of Carbon-Mineral Sorbents Based on Novogorod Sapropel. Part 1

Purification of aqueous media from toxicants carbon-mineral sorbent

To purify aquatic environments from various toxicants, we obtained a carbon-mineral sorbent from the reed stems of the South (Phragmitesaustralis) by carbonization. At the stage of carbonization of the crushed reed, a carcass, containing carbon and silicate constituents, is formed. Depending on the type of feedstock and the carbonization temperature of the organic component, the content of the silicate component varies in the range of 20-30%. The process is carried out until a sorbent containing 70-80% of the carbon component, 29-19% of the silicate component and 1% of water is obtained. The adsorption capacity of the obtained carbon-mineral sorbent towards to medium and macromolecular organic compounds, and heavy metals was studied. As a result, it was established that the carbon-mineral sorbent obtained from the reed stems of the South (Phragmitesaustralis) has moderately distributed sizes of macro- and micropores. The presence of two constituents, carbon and silicate, in the structure of the obtained sorbent promotes the sorption of phenols, hydrocarbons, barbiturates, cholesterol derivatives, aminoglycosides, anthracyclines and other compounds, as well as ions of heavy metals, which makes it possible to use a sorbent in the chemical industry for purification of sewage, natural waters and it can be proposed for the purification of biological fluids.

Modified Sorbents of Sapropel for Wastewater Treatment

There was demonstrated that using that by heat treatment sapropel under air temperature 300 – 350 °C can be obtained bifunctional sorbent capable of removing organic substances and metal ions from aqueous solutions. Sorbent capacity for copper ions is 29,3 ± 2,1 mg/g, for petroleum derivatives – 33,1 ± 2,7 mg/g. There was found that modifying polyhexamethylenguanimidin and humic acids allows expanding possibilities and improving the sorption capacity characteristics of carbon-mineral sorbent.

Regularities of phenol adsorption from aqueous solutions on carbon–mineral materials obtained from bentonite clay

Carbon-mineral materials are obtained by impregnation of bentonite clay with an organic modifier (sucrose) solution under the action of ultrasonic vibration followed by carbonization in water vapor atmosphere. It is shown that the ultrasonic treatment of the clay suspension yields carbon-mineral materials with higher specific surface area and affinity for phenol than those of the starting clay and the material obtained without ultrasonic impact. The adsorption capacity of this sample with respect to phenol is 110 mg/g, which is higher than that of active brown coals. The main parameters affecting phenol adsorption by carbon-mineral materials are pH, sorbent content, phenol concentration, and temperature. The kinetics of phenol adsorption from an aqueous solution on the carbon-mineral sorbent corresponds to a psevdo-first-order reaction with a correlation coefficient of 0.9977.

Methods of preparation and properties of mineral-carbon sorbents obtained from coal-tar pitch-polymer compositions

Abstract The purpose of this study was to determine the possibility of producing hydrophobic mesoporous mineral-carbon sorbents from aluminum hydroxide and coal-tar pitch-polymer compositions by carbonization at 600 °C in an nitrogen atmosphere. The method of homogenization was optimized using different solvents. Blends of aluminum hydroxide and coal-tar pitch with a definite composition or the products of co-precipitation of aluminum hydroxide in the coal-tar pitch-polymer medium were subjected to carbonization process. The hydrophilic–hydrophobic properties were evaluated by adsorption of water vapors. The highest value of BET surface area about 370 m2/g, was achieved for the carbonization product obtained from co-precipitated raw components with 10 wt% coal-tar pitch-polymer compositions.

Obtaining carbon-mineral sorbents based on shungite and using them to clean waste and household water

On the developed technology flotation enrichments of shungit breeds of Kazakhstan the carbon concentrate of a constant chemical compound for alternative replacement of the carbon materials used in electrometallurgy by manufacture of carbon - mineral sorbents, as a substitute of technical carbon and in quality of filler in composite materials can be received.

Use of acenaphthene as a carbon pyrolyzate carrier for the preparation of aluminium-carbon sorbents

The purpose of this study was a preliminary evaluation of mineral-carbon sorbents preparation possibility by the method of thermal decomposition of a mixture of aluminium oxide or hydroxide and acenaphthene and determination of their physicochemical properties. The conditions of carbonization were established and the changes of physicochemical properties of obtained materials as a function of organic substance content in the mineral-carbon mixture before the process of carbonization were tracked. In these investigations the methods of thermal analysis, low-temperature nitrogen adsorption and benzene vapors adsorption were applied.

Adsorption Properties of the Natural Carbon–Mineral Sorbent Shungite

Physicochemical methods were used for a comprehensive study of the structural/sorption properties of the natural mineral shungite. It was shown that the composite structure of the mineral determines its main physicochemical characteristics. The isosteric heat of adsorption of water vapour was estimated by calorimetric methods as 70 kJ/mol. This value corresponds to the interaction of water molecules with the vicinal hydroxy groups of the silica constituent of shungite; adsorption heats with values in the range 40-45 kJ/mol are characteristic of the carbon constituent of the sorbent. The heat of adsorption of benzene onto shungite was higher than that for hexane adsorption onto the mineral, indicating that specific interaction occurs between the benzene molecules and the active centres which exist on both the carbon and silica constituents of the mineral. It was shown that the adsorption parameters of shungite with respect to organic compounds which dissociate in an anionic manner suggest that the mineral ...

Complex Carbon-Mineral Sorbents from Common Clay

Carbon/mineral complexes are materials with surfaces covered partially or totally by carbon materials contains. They have high industrial potential uses as material adsorbents and ceramic filters. The objective of this work is to evaluate the corrosion strength in acid and alkaline solutions, and the adsorption capacity of methylene blue of some materials prepared in the LMPSol. The compositions were prepared with an industrial common clay named “taguá” and organic and inorganic additives from industrial residues up to 50%. The corrosion test was performed in water at 60°C and in aqueous solutions of HCl and NaOH at room temperature, with mass losses measured after 15 days. The samples were pressed manually and heated at different temperatures: 110°C, 350°C and 500°C. The performed tests were transverse flexural strength, porosity and water absorption.

Mineral-carbon sorbents based on post-decarbonization lime and mixture of hydrocarbons

An attempt was made to obtain mineral-carbon sorbents from waste products of petrochemical industry: lime from the decarbonization of river water to be used in technology and hydrocarbon wastes obtained in the treatment of industrial waste waters. The sorbents were prepared by thermal decomposition of mixtures of the mineral and carbon components. In order to optimize the preparation conditions, physicochemical studies were performed of both the mineral matrix and the mineral-carbon sorbents. Adsorption measurements involving nitrogen, water, and benzene as adsorbates were used for determining the parameters of porous structure of the obtained materials and their hydrophilic-hydrophobic properties. The properties influencing the sorptive properties of the organic compounds present in the petrochemical wastes were pointed out.

Precipitated, Coprecipitated, and Carbon–Mineral Sorbents for Isolation of Exracellular Catalase from Penicillium piceum F-648

The abilities of various sorbents to adsorb catalase (CAT; EC 1.11.1.6) from filtered culture liquid (FCL) of the fungus Penicillium piceum F-648 were compared. Potassium phosphate, hydroxyapatite (HAP), and coprecipitated sorbents containing calcium phosphate and magnesium hydroxide adsorbed extracellular CAT more efficiently than aluminum oxide, aluminum phosphate, or quartz sand. The enzyme was isolated from FCL of Penicillium piceum with the use of HAP and a binary coprecipitated sorbent, Ca3(PO4)2 + Mg(OH)2, 1:1 (CM). The CAT(CM) sample contained the least amount of protein admixture. Its spectra had absorption maximums at 279.6, 406.8 (Soret band), 540, 585, 636, and 703 nm and negative molar ellipticity minimums at 207 and 210-214 nm. The kinetic indices of the samples (KM, Vmax:KM, and specific activity) were intricately dependent on protein concentration in the reaction mixture. In dilute solutions, the KM and specific activities of CAT(CM) and CAT(HAP) equaled 667 and 137 mM; 300.9 x 10(4) and 30.0 x 10(4) U/mg protein, respectively. The effective velocity constants of inactivation of CAT(HAP), CAT(CM), and FCL in the reaction of H2O2 decomposition increased dramatically after dilution of samples. In the infinitely dilute solution, they were 4.30 x 10(-2), 6.46 x 10(-2), and 1.12 x 10(-2), respectively.

Adsorption and Structural Properties of Mineral–Carbon Sorbents

In the present work an attempt was made to obtain mineral–carbon sorbents by thermal decompositon. The mineral matrix for the sorbents (aluminium hydroxide) was based on petrochemical waste stream containing considerable amounts of aluminium chloride. Reference tests were carried out with a model solution prepared with the use of analytical grade AlCl3. Atactic polypropylene and hydrocarbon mixtures obtained in the flotation of petrochemical waste waters were used as carbon-containing raw materials.

Mineral-carbon sorbents based on aluminium hydroxide and atactic poly(propylene)

The present work is an attempt to use the waste water stream, containing considerable amounts of aluminium chloride, for the manufacture of mineral-carbon sorbents. The use of the waste water has given a possibility of obtaining a suitable mineral matrix of aluminium hydroxide for the sorbents. Atactic poly(propylene) (APP) have been used as the necessary carbon raw material. The modification of aluminium hydroxide was attained by preliminary mixing with the organic component, followed by carbonisation. Optimum conditions for obtaining Al(OH) 3 have been determined and the effect of the amount of carbon matter on the properties of the materials obtained has been evaluated. The studies have enabled to trace the changes in the structure and properties of the sorbents obtained.