Sorption Properties Of Sorbents Research Articles

Characterization of The Permeation Properties of Membrane Filters and Sorption Properties of Sorbents Used for Polar Organic Chemical Integrative Samplers.

Polar organic chemical integrative samplers (POCIS) are promising devices for measuring the time-weighted average concentrations of hydrophilic compounds in aquatic environments. However, the mechanisms underlying compound uptake by POCIS remain unclear. We investigated the permeation kinetics of polyethersulfone and polytetrafluoroethylene membrane filters, and the sorption kinetics of Oasis HLB (Waters), Envi-Carb (Supelco), and Oasis WAX (Waters) sorbents. The log octanol-water partition coefficient (KOW) values of the 19 targeted compounds ranged from -0.55 to 6.0. The overall mass-transfer coefficients were negatively correlated with KOW, indicating that interactions between hydrophobic compounds and the membrane inhibit permeation. The sorption rate coefficient showed no correlation with KOW and depended on the type of sorbent used. These results imply that the uptake of highly hydrophilic compounds by POCIS is determined by both the membrane and the sorbent kinetics; however, membrane kinetics dominate the uptake of hydrophobic compounds. Environ Toxicol Chem 2024;00:1-7. © 2024 SETAC.

The effectiveness of modified sodium bicarbonate in the purification of exhaust gases from HCl and HF

The effectiveness of gas purification depends on the sorption properties of sorbents. The aim of the research was to determine the ability of sodium sorbents to remove gaseous pollutants such as HCl and HF. The research used baking soda subjected to mechanical and thermal activation, which was introduced into the hot flue gas circuit, similar to the dry flue gas cleaning method used in all kinds of boilers. In almost all cases, mechanical and thermal treatment of baking soda allowed for a significant improvement in the reduction of hydrogen chloride and hydrogen fluoride concentrations in the exhaust gases produced during the combustion of polyethylene terephthalate (PET) bottles. The preparation of sorbents must consider the optimum development of the material's specific surface area, especially during thermal activation, to prevent pores from sintering. In wet and dry flue gas cleaning processes, sodium compounds are used in the power industry. Appropriate preparation of the sorbent allows for improving the effectiveness of reducing the concentration of harmful substances and reducing investment and operating costs. From the point of view of process optimisation, the results obtained will contribute to the identification of optimal operating conditions in dry sorbent injection systems to prevent the pores on the surface of the sorbent from clogging when injected into hot flue gases.

Sorption of copper(II) ions from aqueous solution by activated carbon BAU-A and coal sorbent MIU-S. The relationship between the structure of sorbents and their sorption properties.

The sorption of copper(II) ions in a wide range of pH by two Russian carbon sorbents BAU-A and MIU-S was studied. Sorbents varied in structure, surface area, pH of the point of zero charge (pHZPC), and graphitization degree. The sorption studies were conducted in batch mode. The removal of copper(II) ions from a solution at pH 4, 5, 6, and 6.7 is described by the classical adsorption isotherms of Freundlich, Langmuir, and Dubinin-Radushkevich. With an increase in pH from 4 to 6.7, the sorption capacity of sorbents increases, from 0.910 to 7.163 mg/g for BAU-A, and from 0.265 to 3.307 mg/g for MIU-S. The relationship between the degree of crystallinity and the sorption properties of sorbents has been established.

INFLUENCE OF THE NATURE OF THE MODIFIER ON THE SORPTION PROPERTIES OF SHANKANAI ZEOLITE

Sorbents modified with hydrochloric acid and chitosan based on the Shankanai bridge formation zeolite were obtained, and the effect of drying temperature on the sorption properties of sorbents was studied. It was found that 25 °C is the optimal temperature for obtaining acid-modified zeolite. A chitosan-modified sorbent with good sorption characteristics can be obtained at 25 °C with cation-exchange (COE 68.05 mg-eq/g) and 70°C with anion-exchange (SEC 70.16 mg-eq/g) properties. Physicochemical analysis of modified zeolites showed an increase in the size of voids and channels on the surface of acid-modified zeolite, and when modified with chitosan, the latter is crosslinked with the surface of natural zeolite.

Assessment of sorption properties of sorbent based on silicon dioxide

Effective sorbents are used to address the issues of improving food safety. The economic feasibility of cleaning increases when using food production wastes as sorbents. With the help of modern methods were studied the composition and properties of the sorbent ADC obtained from rice husk. Sorbent is a type of pyrogenic silica. With the help of modern methods for assessing the quality of substances, the chemical composition and morphological features of the surface of the sorbent were studied. In addition, the static exchange capacity for various pollutants was investigated. It is established that the ADC well detains inorganic compounds, which included iron, manganese and aluminum. Desorption of chemical compounds from the used sorbent does not have a significant effect on the content of heavy metals in water. This indicates the strength of sorption bonds. To establish the nature of the moisture in the sorbent with the determination of temperature intervals at which dehydration occurs, a simultaneous thermal analysis was carried out, which allowed determining the temperature zones that correspond to moisture removal, moisture removal with different binding energy, and predict the mode parameters of the moisture removal process and select the most effective way to remove them. dehydration. The operation of the device used is based on the continuous recording of the dependence of the change in mass of the material on time or temperature when it is heated in accordance with the selected temperature program in a given gas atmosphere. At the same time, the release or absorption of heat by the sample due to phase transitions or chemical reactions was recorded. Investigations were carried out under the following conditions: pressure — atmospheric, maximum temperature 600 K, rate of change of temperature 5 °C/min. The experiments were carried out in aluminum crucibles with a total weight of 10 mg. The analysis made it possible to identify periods of dehydration of water during thermal effects on the ADC, as well as to identify temperature zones that correspond to the release of moisture with different shapes and binding energy.

Research of pH influence on sorption properties of sorbents on a basis of residual biomass of microalgae Chlorella sorokiniana and duckweed Lemna minor

This scientific research is determined to a study of sorption process of heavy metal ions removal from aqueous solution at water purification with a help of sorption materials on a basis of residual biomass of microalgae and duckweed. It is known that Chlorella sorokiniana and duckweed Lemna minor have in their composition different valuable substances such as lipids, proteins, pigments, pectic substances. After their extraction residual biomass is formed. And in present study it is proposed for using as biosorbent for water purification. At different pH values the removal of ions of heavy metals (Zn(II), Cd(II), Pb(II), Cu(II)) occurs with varied efficiency; it is an important and informative parameter. Equilibrium and initial concentration of the solution with heavy metal ions were measured by voltammetric method of analysis with a use of special equipment. Chitosan was used as a component for making composite sorption materials with residual biomass of microalgae and duckweed. It is biopolymer which widely used in water purification. Due to this, prepared granules have good sorption properties. Nowadays in the era of technology and wide industrial production it is important and actual to develop new ecological technology and useful materials for water treatment and other fields for environment protection in general.

Preparation and properties of sorbents from the coals of Mongolia

The textural and sorption properties of sorbents prepared by the thermal steam activation of the semicokes of brown and black coals from nine deposits of Mongolia were studied. Their properties were compared with the properties of sorbents prepared from Borodino brown coal and Kuznetsk black coal. A common extremal dependence of the volume of mesopores and the specific surface area on combustion losses was found: a maximum specific surface area of 600–700 m2/g was reached at a combustion loss of 50–60%. Among the Mongolian samples, the sorbents obtained from the brown coals of the Baganuur, Bagankhai, and Shivee Ovoo deposits exhibited the highest surface areas and sorption capacities for iodine. Nearly linear dependence of sorption capacity on specific surface area was found. The sorbents prepared from Borodino brown coals under identical conditions were characterized by a higher degree of combustion losses because of the increased concentrations of catalytically active calcium compounds in them.

Sorption of strontium by the endoreceptor dibenzo-18-crown-6 immobilized in a polymer matrix

A set of new sorbent were obtained by impregnation different amounts of endoreceptor dibenzo-18-crown-6 in the styrene–divinylbenzene polymer matrix “Porolas-T”. Physical and chemical parameters of strontium sorption on a natural mixture of isotopes from nitric acid solutions were investigated, namely isotherm of sorption, dependence of the distribution coefficient on the concentration of nitric acid in a solution and concentration of crown ether in the sorbent, kinetics of sorption and desorption of strontium. The selectivity of strontium sorption was studied to the alkaline, alkaline-earth metals and cobalt. The sorption properties of sorbent were examined to extraction of radioactive 90Sr.

Sorption properties of sorbents based on polyvinyl chloride foam

Sorbents based on polyvinyl chloride foam (expanded polyvinyl chloride) for sorbing oil and oil products from a water surface are proposed. It is shown that the sorption capacity of the sorbents can be controlled within wide limits by varying the volume weight of the sorbents. The change in sorption capacity of the sorbent is found to be dependent on the multiplicity (frequency) of regeneration and thickness of the oil layer on the water surface.