Natural Mineral Sorbents Research Articles

On the effect of thermal activation on the surface chemistry of natural mineral sorbents

The article discusses adsorbents, their characteristic features, structural sizes, geometric forms, porosity, the concept of porosity and the influence of their thermal activation on the structure and sorption parameters of natural mineral sorbents - Angren kaolin and Azkamar bentonite. Here is given the chemical composition of kaolin and bentonite clay samples before and after thermal activation. Thermal activation of kaolin clay at 1023K is shown, which has almost no effect on the content of basic oxides in the clay mineral. It leads to the removal of adsorbed moisture and partially constitutional water, as a result of which the mass loss on ignition (WLP) of a thermally activated kaolin clay sample is reduced. The adsorption isotherms of water vapor on thermally activated samples of kaolin and bentonite have an S-shape according to the BET classification, which is due to capillary condensation in the P/P-1.0 region. All isotherms are characterized by the presence of a hysteresis loop over the entire range of relative pressures. The reason for the appearance of a hysteresis loop in the case of sorption of water vapor is associated with the swelling of clays in the vapor phase. The change in the chemical composition of the initial and clays activated at 1023K is shown in the form of a table. Based on the research, it was concluded that during thermal activation of PMS, processes associated with dehydration and dehydroxylation occur, which leads to changes in porosity, specific gravity, and total pore volume.

Technology of activation of natural mineral sorbents

The article interprets the experimental results for the technology of activation of natural mineral sorbents and plans for activation and determines particle size, surface area, mechanical strength,the density of sorbents based on bentonite. As a result of data processing, the regression equation representing the process of alkaline activation of bentonite and the optimal variant of the experimental mode were selected.Based on the conducted experiments, the following optimal conditions for bentonite activation were determined: NaOH concentration 5.5%; activation time 2.75 hours; S:L ratio-1:2(S-solid, L-liquid); the device consists of observers in the reactor for enamel-coated ultra-fighting environments, a tank for acid storage and solution preparation, neutralization of saline residues, and washing parts. The process of zeolite activation was carried out in the mechanism of ion exchange, Н+ions were replaced, and part of the exchange was carried out by a complex of cations: Na+, K+, Ca2+, Mg2+. The specific activation loss per unit mass of HCl sorbent was determined by the decrease in the content of cations in the exchange complex. According to the experiment, the concentration of hydrochloric acid in the residual solution was 4.24% after activation.The purpose of the work is to develop the technology of activation of natural mineral sorbents and to study the conditions of activation by mathematical methods and statistical calculations, processing the results of experiments, i.e. to determine the specific surface area, particle size, true density, mechanical strength.

Агроинженерная технология улучшения качества дренажно-сбросных вод с рисовых оросительных систем

Under condition of water shortage slow-mineralized drainage water coming from the rice irrigation systems can be used as an additional source of water. Agro-engineering technology on drain-age flow treatment and its reusing for irrigation has been devel-oped and tested by the authors. Agro-engineering technology in-cludes: 
 1) biosorption facility to remove mineralsalts with the help of specially selected natural mineral sorbents, 
 2) higher aquatic vegetation to absorb biogenic substances; 
 3) the developed new sorbent to provide water conditioning. The results of biosorption facility testing carried out at the Sarpin irrigation system in the Republic of Kalmykia showed its high ef-ficiency.
 A decrease in drainage flow mineralization was observed (from 4.3 to 0.66 g/l), while chlorine decreased from 78 to 28 mg/l, as well as calcium increased from 100 to 124 mg/l. So the efficiency of the suggested technique of drainage flow treatment is rather high which made it possible to use purified drainage flow for irrigation purposes without negative consequences. The appli-cation of the developed technology will get an economic effect by reducing the cost of water supply for the rice irrigation system.

Study of the natural mineral sorbents’ absorption properties of the Ural region (Russia)

The article is devoted to the study of the sorption properties of natural mineral sorbents from deposits located in the Ural (Sverdlovsk, Kurgan, Chelyabinsk regions). For the experiments, the following natural sorbents were used: bentonite clays with an admixture of carbonate inclusion; flasks - dense, slightly porous rocks consisting of the smallest particles of biogenic silica; diatomite; glauconites- layered low-temperature ferruginous micas; calcined vermiculite. The absorption capacity in relation to heavy metals: copper, zinc, lead, cadmium, nickel, chromium, arsenic has been investigated. The are no significant differences in the completeness of sorption between the studied sorbents, all of them can be successfully used under certain conditions for ecological and geochemical recultivation of soils contaminated with HMs. Separately, the influence of sorbents on the copper and chromium absorption as the largest soil pollutants in the Urals was considered. Experiments have shown that copper in the form of a bivalent cation is well sorbed by all sorbents, while chromium in the form of a complex anion (in a hexavalent form) is practically not sorbed. To ensure a proper chromium sorption effect, it was decided to preliminary transfer it into a trivalent cationic form by a reducing agent, which was ferrous ammonium sulfate - FeSO4·(NH4)2·SO4·6H2O. The reduction of chromium to a trivalent cation increases the sorption completeness to 94-99%.

Study of the new composite sorbents for water treatment

Water pollution has become one of the key global environmental problems. Heavy metal ions are the main pollutants of water. Therefore, this study focuses on the manufacture of a highly efficient filter that absorbs heavy metals for water purification using inexpensive materials. The article discusses and shows the possibilities of using new sorption materials for water softening purposes. Experimental data on the study of sorption properties of the developed material are presented. Possible ways to improve the water treatment existing scheme of the enterprise are proposed. The study object was natural mineral sorbents, promising for use in water purification and conditioning processes. The work aim was to experimentally evaluate the use effectiveness of natural mineral sorbents for water purification. Research by using modern physico-chemical methods, it has been shown that natural mineral sorbents effectively purify water from pollution. The most promising natural mineral sorbents turned out to be the flask of the Taskala deposit of the West Kazakhstan region to purify water from heavy metal ions. Natural mineral sorbents purify water from excess iron ions and have pronounced sorption properties

Mineral Inactivation of Zinc in Polluted Soil—Sustainability of Zeolite, Bentonite and Blends

The study outlines a novel and traceable procedure for inactivating zinc polluted soil (an Anthrosols) adjacent to a former zinc (Zn) ore mine “Orzel Biały” in Bytom (Poland), where the total content of Zn amounted to 3988.0 mg kg−1. This pollution level initiated an inactivation process involving two natural mineral sorbents, i.e., zeolite (Z) and bentonite (B), as well as their five blends (ZeoBen) expressed as ZB: (1) ZB15/85, (2) ZB30/70, (3) ZB50/50, (4) ZB70/30 and (5) ZB85/15. Next, phosphorus (P) as triple superphosphate (TSP, 46% P2O5) was added to individual ZB at rates: 0.25%, 0.5%, 1.0% and 2.0%. All sorbents were added to the Zn polluted soil at 0%, 0.25%, 0.5%, 1.0% and 2.0% (dry weight basis). Treatments (1.0 kg of Zn-polluted soil with ZB sorbents) were aged for 115 days. Data revealed that ZB85/15 with prevailing zeolite caused a Znact inactivation of 66–71%, while zeolite induced 54% and 47% for bentonite. Reactive zinc (Znreac) decreased much more (20%) when zeolite was incorporated at the rate 2.5 g·kg−1 soil, and bentonite was (10%) at the same rate. The application of the sorbent ZB50/50 enriched with triple superphosphate (TSP) raised the stabilization degree for both Zn fractions. The efficiency was significant at the TSP rate of 2.0% of the sorbent and at least the sorbent +TSP of 10 g·kg−1 soil. The cation exchange capacity (CEC) of about 2 cmol(+)·kg−1 controlled the activity −0.50 mmol·dm−3 of either γZnreac or γZnact, hence a very low zinc ionic activity. The use of mineral blends with higher sharing of zeolite is promising for remediating metal-polluted lands in the case of zinc.

The Kinetics of Manganese Sorption on Ukrainian Tuff and Basalt—Order and Diffusion Models Analysis

The study aimed to determine the nature of the kinetics of the manganese sorption process on Ukrainian tuff and basalt at different temperatures characteristic of the natural water environment. The scope of the research included manganese sorption kinetic test on natural mineral sorbents at temperatures of 10, 17.5 and 25 °C in slightly acidic conditions. Sorption (pseudo-first order, pseudo-second order and Elovich models) and diffusion kinetic models (liquid film diffusion and intraparticle diffusion) were used in the analysis of test results. The manganese sorption process on both tuff and basalt proceeded quickly. The dynamic equilibrium state of manganese sorption settled after 35 and 45 min on tuff and basalt respectively. Although the process took place in a slightly acidic environment and below pHPZC of the sorbents, possible electrostatic repulsion did not inhibit the removal of Mn. The Mn sorption on both materials followed the PSO kinetics model. Based on the diffusion kinetic models, it was determined that Mn sorption process on both materials was influenced by diffusion through the boundary layer and intraparticle diffusion. The differences in removal efficiency and rate of Mn sorption in the temperature range of 10–25 °C were not found.

Characteristics of Natural Mineral Sorbent for Water Treatment of Drinking Water from Underground Sources

The results of research of sorption characteristics of natural mineral material – marsh ferromanganese ore are presented. Indicators of physical properties and mechanical strength, specific surface area of grains of ore samples were determined. The high efficiency of extraction of manganese and iron ions from underground waters by this natural material without the use of additional reagents is revealed. The kinetics of the sorption process was studied. It is shown that the extraction of manganese and iron ions from water solutions by marsh ferromanganese ore proceeds by a sorption-catalytic mechanism. For each ion, the values of the sorption capacity of the sorbent, the sorption equilibrium constants, and the kinetic parameters of the sorption process are calculated.

ВИКОРИСТАННЯ ПРИРОДНИХ ТА АБСОРБТИВНИХ СУБСТАНЦІЙ ДЛЯ ОЧИЩЕННЯ ПРИРОДНИХ ТА СТІЧНИХ ВОД

The article deals with the use of biological agents (microorganisms, plants and fish) in the systems of the natural and water treatment which can be organization formed as natural ecosystems as a bioplateau and managed as after composition and duration of functioning.
 It is shown that quality and perspective material in the processes of cleaning of drinkable and sewer waters are natural mineral sorbents. Their value is determined by high porosity, largeness of and absorption properties, by possibility sorbents the substances of inorganic and organic origin, by a capacity for a regeneration. Charts of cleaning of drinkable and sewer waters, where the modified basaltic tuffs come forward in quality of filter sorbent, are expedient and economically advantageous, and simplicity of apparatus registration allows their introduction on water-purifying building.

Use of glauconite as a non-reagent sorbent for the softening of drinking and boiler waters, industrial waste water

The article discusses the sorption of purification of water bodies from impurities using natural inorganic sorbents. The availability and low cost of minerals are an important economic advantage of their use for the purification of all types of water. The article describes a method of using an effective sorbent with high ion-exchange and sorption properties for purification of light oil products, for the purification of drinking or industrial water with a high content of heave technogenic metal ions and organic substances. Based on the data obtained, conclusions are drawn about the possibility of using the studied natural mineral sorbents for the extraction of impurities from waste and natural waters.

Use of glauconite as a non-reagent sorbent for the softening of drinking and boiler waters, industrial waste water

The article discusses the sorption of purification of water bodies from impurities using natural inorganic sorbents. The availability and low cost of minerals are an important economic advantage of their use for the purification of all types of water. The article describes a method of using an effective sorbent with high ion-exchange and sorption properties for purification of light oil products, for the purification of drinking or industrial water with a high content of heave technogenic metal ions and organic substances. Based on the data obtained, conclusions are drawn about the possibility of using the studied natural mineral sorbents for the extraction of impurities from waste and natural waters.

IONITES ON THE BASIS OF CLINOPTILOLITE


 
 
 Organomineral ionites have been synthesized, in which natural mineral sorbent is chemically bound to organic part of a molecsule, containing ionogen groups. Ionogen groups of these ionites contribute to efficient exchange in water solutions. They might be used for cleaning drainage waters and technical solutions, as well as for purification of medicinal preparations from various admixes. Hydrogen forms of natural zeolite - clinoptilolite and bromoacetic acid were used to resolve this problem. Chemical modification of clinoptilolite, by inculcation of ionogen groups into zeolite skeleton, enables us to increase significantly ionite exchange capacity. Static exchange capacity of a cationite with carboxyl ionogen groups increases from 0,1 - 0,9 (for chemically unmodified zeolite) to 5- 6 мg.equiv./g.
 
 

Дослідження адсорбційного вилучення іонів нікелю(ІІ) бентонітовими глинами

The process of sorption of nickel(II) ions with a fixed layer of sorbent by bentonite clays has been investigated. The main advantages of using bentonites in water treatment technologies are described: powerful geological reserves, cheap rock formation, simple preparation for transportation and use, the possibility of using spent sorbents in other technologies, thus eliminating the need for expensive ones at the cost of regeneration. The influence of different factors (length of process, layer of adsorbent) on the degree of wastewater treatment from nickel ions, influence of pump speed on dynamic capacitance of sorbent is investigated and effective volume is determined. The effectiveness of adsorption increases with increasing the layer of adsorbent, which can be explained by the development of active sorption surface. As the initial concentration of nickel ions increases, the time of appearance of the first traces is polluted at the exit of the column, as well as the total time before the breakthrough. The results of the studies indicate a higher adsorption capacity of modified bentonite in relation to Nickel ions compared with its natural form. The maximum absorption of nickel(II) ions in modified bentonite occurs at a layer of sorbent 20 g for 4,5 hours and is 73,4 %. The results of the research indicate that the use of natural mineral sorbents is effective, in particular, the bentonite clay of Cherkassy deposit for cleaning of waste water from nickel(II) ions.

Sorption of molybdenum(VI) ions on natural mineral sorbents

The sorption of Mo(VI) ions on natural sorbents (zeolite tuffs and clinker) is investigated. It is estimated that zeolite tuffs sorb polymer forms of Mo(VI) ions in acidic media, while the monomer form of molybdate ion is sorbed in basic media. It is concluded that the rate of sorption of molybdenum(VI) ions on zeolite tuffs is regulated by an intradiffusional mechanism. Values of the activation energy indicate that the adsorption of molybdenum(VI) ions on zeolite tuffs is governed by a physical mechanism. The excretion of crystalline phase (probably calcium molybdate) on surfaces of zeolite tuff is estimated via scanning electron microscopy.

Determination of the sorption characteristics of glauconite during extraction of a pharmaceutical from an aqueous medium

A technique for preparing enriched glauconite on the basis of a natural mineral from the Beloozyorskoe field of Saratov oblast has been developed. The results of a study of the chemical composition, surface structure, and certain physicochemical properties of the samples of the sorbent are presented. The sorption of ambroxol hydrochloride ions from aqueous solutions has been studied using natural and enriched glauconite. The sorption isotherms, are approximated by the Langmuir equation, have been obtained, and the values of the maximum sorptive capacities have been calculated. Based on the obtained data, conclusions have been drawn on using the studied natural mineral sorbents to extract the above-mentioned substance from aqueous solutions.

Geochemical aspects of environmentally safe conservation of liquid radioactive waste

Physicochemical features of the sorption of Sr, Cs, and U radionuclides on natural mineral sorbents (montmorillonites of Na and Ca type, kaolinites, illites) were studied. The main processes responsible for binding and retention of radionuclides are ion exchange and formation of complexes on the mineral surface. The influence of pH, salt composition of the solution, specific surface area of the sorbent, and its pore size on the radionuclide immobilization efficiency was examined.

The use of composite ferrocyanide materials for treatment of high salinity liquid radioactive wastes rich in cesium isotopes

Abstract The use of composite materials based on metal ferrocyanides combined with natural mineral sorbents for treatment of high salinity Cs-containing liquid radioactive waste (LRW) was investigated. The study indicated that among the investigated composites, the best sorption characteristics for Cs were shown by materials based on copper ferrocyanide. Several factors affecting the removal of cesium from LRW, namely total salt content, pH and organic matter content, were also investigated. High concentrations of complexing organic matter significantly reduced the sorption capacity of ferrocyanide sorbents.

Removal of Gas-Phase Elemental Mercury in Flue Gas by Inorganic Chemically Promoted Natural Mineral Sorbents

A variety of natural mineral sorbents were synthesized and tested on a lab-scale fixed-bed system to evaluate mercury removal efficiencies under a simulated flue gas condition that contains 84% N2, 4% O2, and 12% CO2 in volume fraction. Three types of natural minerals, bentonite (Ben), mordenite (Mor), and attapulgite (Atp), were selected as raw sorbents, and several chemical promoters, such as CuCl2, NaClO3, KBr, and KI, were employed to enhance mercury removal abilities of the raw sorbents. The physical-chemical characteristics of these minerals were analyzed by an X-ray diffractometer (XRD), an accelerated surface area and porosimeter (ASAP) using the N2 isotherm adsorption/desorption method, and X-ray fluorescence (XRF) spectrometry. The mercury concentration was detected continuously using a VM3000 online mercury analyzer. The results showed that CuCl2-impregnated Atp (Cu-Atp) and CuCl2-impregnated Ben (Cu-Ben) presented about 90% average Hg0 removal efficiencies at 120 °C, respectively. In addition, as the temperature increased, the removal efficiencies decreased. Although NaClO3-impregnated Atp showed an average Hg0 removal efficiency more than 90% at 120 °C, its performance was limited by the testing temperature, and that was probably due to the high iron oxide content in Atp. For the KI-impregnated sorbents, high mercury removal efficiencies could be observed, and the efficiencies increased steadily with the temperature increased from 70 to 150 °C. The three natural minerals presented poor adsorption abilities for bromine, which resulted in the disappointing mercury removal efficiencies. Generally, Cu-Atp, Cu-Ben, and KI-impregnated sorbents were promising cost-effective mercury sorbents.

CLEANING OF WATER RADIOACTIVE SOLUTIONS FROM RADIONUCLIDES BY MEANS OF NATURAL SORPTION DISPERSION MINERALS AND THEIR IMMOBILIZATION

The article is aimed at a solution of the environmental problems of nuclear energy, in particular methods of wastewater treatment of the nuclear and radiochemical industry, as well as the natural aquatic environment from radioactive isotopes. The proposed method of radioactive effluent cleaning is based on the use of natural mineral sorbents with high specific surface attained by partial cleavage of minerals by chemical, mechanical, hydrodynamic, electrodynamics, plasma, or cavitations method − partly to the nanoscale. The described method allows the article to reduce the environmental tensions over nuclear energy with minimal material costs for radioactive effluent cleaning in connection with the use of common natural minerals as initial materials for the sorbent manufacture. The possibility of radioactive effluent purification with high salt background and containing impurities in the form of organic and mineral oils in the form of surface?active substances is proved. Besides, the method of distillation residue evaporation which one holds in the presence of oxidant aeroions at preliminary brought in a mud nonstructural sorbent affected by natural aluminum silicate is stated in the paper. It is demonstrated in the paper that except for sorption of radionuclide's nonstructural sorbent, it possesses the capacity to sorb high-gravity metals, salts, borates, and other toxic matter and to execute the function of the astringent materials.

Natural mineral sorbents for chemical and microbiological purification of potable water

The role of a number of rocks (shungite, glauconite fossil rock, flint) in a chemical and microbiological purification of water was estimated. On the basis of a shungite-dolomite module a simple method for a widescale manufacture of chemically and microbiologically pure potable water with conditionated content of mineral matters was developed.