Wyniki wyszukiwania - Biblioteka Nauki

1

Characteristic curves for gases at supercritical temperatures. Adsorption equilibria of methane and nitrogen on molecular-sieve carbon

100%

Warmuziński K. , Zielińska I. , Śmigasiewicz S.

Inżynieria Chemiczna i Procesowa

|

1999

|

tom T. 20, z. 4

613-627

EN

The evaluation of some of the principal correlations that describe adsorption equilibria for gases at supercritical temperatures is carried out. Based on the experimental data for the adsorption of methane and nitrogen on a carbon molecular sieve 5A (Takeda) it is found that the four-parameter characteristic curve of Amankwah and Schwarz seems to be superior to the three-parameter Dubinin-Astakhov equation. It is also demonstrated that, since the parameters visibly depend upon both the type of equation and the accuracy of the experimental data and regression procedures employed, caution should be exercised in ascribing any specific physical significance to the values of these parameters.

PL

Dokonano przeglądu podstawowych korelacji opisujących równowagi adsorpcyjne gazów powyżej temperatury krytycznej. Opierając się na danych równowagowych dla metanu i azotu na węglowym sicie molekularnym 5A (Takeda) stwierdzono, że czteroparametrowa krzywa charakterystyczna Amankwaha i Schwarza lepiej koreluje punkty eksperymentalne niż trójparametrowe równanie typu Dubnina-Astachowa. Stwierdzono jednak, że wobec wyraźnej zależności parametrów od rodzaju korelacji oraz dokładności danych eksperymentalnych ( a nawet typu stosowanych metod regresyjnych), należy zachować ostrożność w przypisywaniu wartościom tych parametrów jednoznacznego sensu fizycznego.

2

A direct method of studying colloid interactions and adsorption at solid / liquid interfaces

100%

Adamczyk Z. , Szyk L. , Warszyński P.

Bulletin of the Polish Academy of Sciences. Chemistry

|

1998

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tom Vol. 46, No. 4

425-439

EN

A new cell for direct in situ observations of colloid particle adsorption was developed. The controlled convective transport conditions were created by exploiting the slot impinging jet (SIJ) principle. Numerical solutions of the governing Navier-Stokes equation showed that the flow pattern in the cell can be approximated by the planeparallel stagnation flow with the perpendicular velocity component independent of the lateral distance X. Thus, the solid/liquid interface at distances close to the symmetry plane was found uniformly accessible for particle transport. This flow field was used to derive the mass transport equation which was then numerically solved to obtain the initial flux (adsorption rate) for various transport conditions. These theoretical predictions were verified experimentally using monodisperse polystyrene latex particles. A good agreement between predicted and measured initial flux was found for a broad range of Reynolds number and ionic strength of the particle suspension. This confirmed that the SIJ cell can be used as a useful tool of studying colloid and bioparticle interactions and adsorption under well-defined transport conditions.

3

Two-stage membrane separation process for biohydrogen recovery

80%

Búcsú D. , Bélafi-Bakó K. , Pientka Z.

Environment Protection Engineering

|

2005

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tom Vol. 31, nr 3-4

33-38

EN

Porous and non-porous gas separation membranes were used for concentration of biohydrogen produced by a heterotrophic hyper-thermophilic, anaerobic micro-organisms. A laboratory-scale integrated system was designed and built based on a liquid seal system and more than 70% hydrogen concentration was achieved from the initial gaseous mixture containing hydrogen, carbon dioxide and nitrogen. Liquid absorption and desorption of the carbon dioxide were also studied.

4

Removal of heavy metal ions: copper, zinc and chromium from water on chitosan beads

80%

Jaros K. , Kamiński W. , Albińska J. , Nowak U.

Environment Protection Engineering

|

2005

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tom Vol. 31, nr 3-4

153-162

EN

The paper deals with the application of chitosan in the form of beads to the removal of copper, zinc and chromium ions from water. The main element of the experimental equipment was a glass column, 5 cm in diameter and 30 cm high. The column was filled with chitosan beads. The research was car-ried out in one-, two- and three-component solutions, at the initial concentrations c0 ranging from 50 to 70 mg/dm3.In the description of metal sorption kinetics, the second-order equation was used. It well describes experimental data (its correlation coefficient ranged from 0.94 to 0.99).

5

A Review on the Adsorption of Phenol Derivatives from Wastewater

80%

Benaddi R. , Osmane A. , Zidan K. , El Harfi K. , Ouazzani N.

Ecological Engineering & Environmental Technology

|

2023

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tom Vol. 24, iss. 4

35--43

EN

Several environmental companies consider phenols compounds to be very dangerous pollutants because they are highly toxic and non-biodegradable, notably their high toxicity in water. For this reason, several processes have been studied by researchers to understand the mechanisms of elimination of phenolic compounds. Adsorption remains the best technique due to its characteristics, in fact, it is non-destructive and simple to use as well as have more other advantages, such as practicality and efficiency and low cost, Therefore, these methods need to be widely developed on an industrial scale to remove phenol derivatives and achieve wastewater quality in accordance with standards. On the other hand, the development of these adsorption methods is highly dependent on new research on materials from abundant natural resources, namely apatites or biomaterials.

6

Adsorption of Naproxen Sodium from Aqueous Solutions on Commercial Activated Carbons

80%

Lach J. , Szymonik A.

Journal of Ecological Engineering

|

2019

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tom Vol. 20, nr 10

241--251

EN

The pollution of surface and drinking water with pharmaceuticals is one of the growing problems. One of the groups used in large quantities involves nonsteroidal anti-inflammatory drugs which can be bought without a prescription. This group includes naproxen, which was identified in wastewater, surface water and even drinking water all over the world. The aim of the study was to assess the opportunities for the removal of naproxen sodium from water using carbon sorbents. The measurements were carried out for three commercial microporous (WG-12 and F-300) and micro-mesoporous (ROW 08 Supra) activated carbons. The kinetics and statics of adsorption were studied. The adsorption from solutions with pH from 6 to 10 and temperature from 20°C to 40°C was analysed. It was found that the higher the pH, the lower the adsorption and the higher the temperature, the greater the adsorption of naproxen sodium. The highest adsorption of naproxen sodium was obtained for the F-300 activated carbon, whereas the lowest – for the ROW 08 Supra activated carbon. It was found that the adsorption results depend on many factors, the most important of which include hydrogen bonds between carboxyl groups of naproxen sodium and phenolic groups on the surface of activated carbons and electrostatic repulsion between the anions of naproxen sodium and negatively charged the surface of the activated carbon. The results of adsorption kinetics were described with the following models: pseudo-first order and pseudo-second order, intraparticle diffusion, and Elovich. The highest values of correlation coefficient R2 were obtained for the pseudo-second order and Elovich model. The results of adsorption statics were described using the Freundlich, Langmuir, and Temkin models. A good match between isotherms and the obtained results was obtained for the Freundlich and Temkin equations. It was found based on the adsorption intensity 1/n and distribution coefficient RL that this process was beneficial for all the considered activated carbons and the investigated adsorption conditions.

7

ATORVASTATIN ADSORPTION STUDIES ON CHITOSANS IN AN in vitro PHARMACEUTICAL MODEL

80%

Meler J. , Grimling B. , Szcześniak M. , Karolewicz B. , Biernat P.

Progress on Chemistry and Application of Chitin and its Derivatives

|

2018

|

tom 23

140 - 148

EN

During the pharmacological therapy of specific diseases, drugs are used which, with other preparations or foods, can create connections, in many cases changing or even blocking their action. On the other hand, the use of unsuitable polymers as excipients may result in drug-polymer incompatibilities. Interactions consisting mainly of the occurrence of the adsorption phenomenon and on the formation of complex bonds that reduce the effect of the drugs are of particular importance. The aim of the study was to investigate whether the active substance atorvastatin is incompatible with dietary supplements containing chitosan. The phenomenon of the adsorption of the drug was examined using a static model of a pharmaceutical gastrointestinal tract, in the concentration range generally ingested in a single dose. Measurement results of the amount of bound drug were used to determine the average percentage of adsorbed drug dose. The results of the study prove that the anticholinesterase drug is adsorbed on chitosan in the pH ranges used, and that the binding capacity depends on the chitosan variety, which indirectly affects the reaction of the environment. It was observed that the average size of sorption depending on the chitosan variety ranged from 38% to 86%. The fact that the lowest value of adsorption was at pH 6.4 can be explained by the chemical properties of chitosan, which shows a charge only at pH >6.7. Under such conditions, the phenomenon of electrostatic adsorption may occur in relation to the healing substances of weak acids. At a pH above 7.6, corresponding to the intestinal fluid-filled intestine, the mean sorption for the highest dose of chitosan was from 38–86%. The increase in the adsorbed amount of anticholinesterase drugs on the polymer along with the increase in pH from 7.6 to 8.0 can be explained by the chitosan swelling properties, which increase with an increase in the pH. As a result, the specific surface area of the polymer and its sorption capacity increase. Based on the above considerations, it can be concluded that there is an antagonistic interaction between the drug and the polymer studied, which involves the adsorption of a drug from this group on the polymer (chitosan) and a decrease in its bioavailability

8

Badanie równowagi procesu adsorpcji mocznika na wymieniaczu jonowym Wofatit KPS

80%

Robak A. , Piotrowski J.

Chemia i Inżynieria Ekologiczna

|

2000

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tom Vol. 7, nr 1-2

79-85

PL

Wyznaczono równowagę procesu adsorpcji mocznika z roztworów wodnych na wymieniaczu jonowym Wofatit KPS w zakresie temperatury 298-323 K oraz stężeń mocznika 0,8-10 g/dm3. Rezultaty badań przedstawiono w postaci izoterm Langmuira, Freundlicha i Dubinina-Raduszkiewicza. Podano izosteryczne ciepło adsorpcji mocznika. Wykazano fizykalny charakter procesu sorpcji mocznika na kwaśnym wymieniaczu jonowym.

EN

The equilibrium of the urea adsorption process from its aqueous solutions on ion-exchange regin Wofatit KPS in the range 298-323K and urea concentration 0,8-10 g/dm3 has been studed. Results were presented in the form of Langmuir, Freundlich and Dubinin-Raduszkiewicz isotherms. The isosteric heat of urea adsorption was determined. Physical character of the urea adsorption on acid form ion-exchanger was proved.

9

Methods of Dyes Removal from Aqueous Environment

80%

Bożęcka A. , Orlof-Naturalna M. , Kopeć M.

Journal of Ecological Engineering

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2021

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tom Vol. 22, nr 9

111--118

EN

In this paper, selected methods of dyes removal from water environment were discussed, with particular attention to the adsorption method. A literature review of the latest scientific research on colour impurities removal with the use of various types of adsorbents was presented. The efficiency of the methylene blue removal process, with use of selected natural sorbents and activated carbons, was tested. The competitiveness of natural sorbents was shown. It was confirmed that these materials are efficient in removing coloured compounds from aqueous solutions.

10

Layered Double Hydroxide/Chitosan Composite (Mg-Al/CT) as a Selective Adsorbent in Congo Red Adsorption from Aqueous Solution

80%

Mohadi R. , Siregar P. M. S. B. N. , Palapa N. R. , Taher T. , Lesbani A.

Ecological Engineering & Environmental Technology

|

2022

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tom Vol. 23, iss. 2

144--152

EN

Layered double hydroxide (LDH) can be used as an adsorbent to remove pollutants from aqueous solutions, but it drawbacks where the structure is easily damaged so that it cannot be reused in the adsorption process and has a low adsorption capacity. This can be overcome through the development of layered double hydroxide material composited with chitosan support material. In addition to untilizing waste, chitosan is selected as supporting material in the layered double hydroxide modification process, because it is cheap, has high selectivity, and is biodegradable. In this study, the adsorbent was applied in the process of removing Congo Red (CR). The LDH modification process using chitosan was successfully carried out, as seen from XRD analysis which resembled the base material (Mg-Al) and support (CT), the BET analysis which showed an increase in surface area, as well as from the large adsorption capacity value and the regeneration process which tends to be stable after compositing is done.

11

Binding features of N-hexadecanoylglycine on two terminations of fluorapatite (001) surface and their effect on fluorapatite flotation

80%

Zou H. , Liu D. , Cao Q. , Chen X.

Physicochemical Problems of Mineral Processing

|

2020

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tom Vol. 56, iss. 5

949--959

EN

N-hexadecanoylglycine (C16Gly) is a newly synthesized collector, which can be used as an efficient collector for fluorapatite (FA) rather than for dolomite. To extend our knowledge regarding the C16Gly collector, the contact angle method was employed to understand the flotation selectivity of C16Gly in the FA and dolomite system. On the other hand, the possible binding models of C16Gly anion on Ca-rich and PO4-rich terminations of FA (001) surface were investigated with density functional theory calculations to reveal the interaction between the C16Gly and the FA surface. Results showed that C16Gly anion could interact with these two terminations to generate 12 low-energy configurations, including bidentate, tridentate and chelating binding models. The C16Gly anion preferred to adsorb onto the Ca-rich termination, which is caused by the weaker electrostatic repulsion force between the C16Gly anion and the PO4 groups on this termination. The adsorption of C16Gly on these terminations was more stable than that on the dolomite (104) surface, which is one of the reasons for the preferential flotation of FA from dolomite using C16Gly as a collector. These findings provide further insights into the selectivity of C16Gly during the flotation of FA and dolomite.

12

Activated carbons for the removal of heavy metal ions: A systematic review of recent literature focused on lead and arsenic ions

80%

Deliyanni E. A. , Kyzas G. Z. , Triantafyllidis K. S. , Matis K. A.

Open Chemistry

|

2015

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tom 13

|

nr 1

EN

This work is a systematic review of the literature over the past decade of the application of activated carbon (microporous or mesoporous) as adsorbents for the removal of heavy metals, focusing especially on lead (Pb) and arsenic (As) ions from the aqueous phase. Classical examples from our lab are also given. Activated carbon is known to provide a high surface area for adsorption. Generally, surface modification is typically required, such as oxidation, treatment with ammonia or even impregnation with ferric ion, etc. and the adsorbent material may originate from various sources. The pristine materials, after modification and those after batch-wise adsorption, were characterized by available techniques (BET analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, thermal analyses, X-ray photoelectron spectroscopy). Adsorption isotherms, thermodynamics and kinetics of the process are also discussed. Selected studies from the literature are examined in comparison with other adsorbents. The role of chemistry in the metals adsorption/removal was investigated.

13

Sorption of the anionic reactive red RB dye in cellulose: Assessment of kinetic, thermodynamic, and equilibrium data

80%

Silva L. S. , Lima L. C. B. , Ferreira F. J. L. , Silva M. S. , Osajima J. A. , Bezerra R. D. S. , Filho E. C. S.

Open Chemistry

|

2015

|

tom 13

|

nr 1

EN

The cellulose matrix was characterized by FTIR, 13C NMR, XRD, TG, SEM and applied in the removal of the reactive red RB dye in an aqueous medium, with a capacity of adsorption at a pH of 2.0, and an adsorption equilibrium time which was reached at around 200 mins. The kinetic study for the system followed the Elovich model. The adsorption isotherms for the system at temperatures of 35°C, 45°C, and 55°C were adjusted to the Langmuir, Freundlich, Sips, and Redlich-Peterson non-linear models, with a capacity of adsorption for adsorbent of 5.97 mg g-1, 5.64 mg g-1, and 4.62 mg g-1, respectively. The adsorption occurred by electrostatic interactions and it was favorable and spontaneous, with the influence of temperature.

14

THE USE OF ACTIVE CARBON IMMOBILISED ON CHITOSAN BEADS FOR RB5 AND BV10 DYE REMOVAL FROM AQUEOUS SOLUTIONS

80%

Filipkowska U. , Jóźwiak T. , Szymczyk P. , Kuczajowska-Zadrożna M.

Progress on Chemistry and Application of Chitin and its Derivatives

|

2017

|

tom 22

14-26

EN

This paper presents the adsorption of dyes – the anionic Reactive Black 5 (RB5) and cationic Basic Violet 10 (BV10) dyes – on activated carbon (AC) immobilised on chitosan (CHs). The results were compared with the removal efficiency of RB5 and BV10 on the individual sorbents: chitosan beads and activated carbon. In this study, the sorption capacities of the sorbents, sorption pH and the point of zero charge (pHZPC) were determined. For the description of the obtained results, the Freundlich, Langmuir and double Langmuir models were used. The results show that the developed sorbent (CHs-AC) is effective for both types of dye (RB5 or BV10) over a broad pH range 4–10, which makes it a universal sorbent. The maximum sorption capacity of CHs-AC with RB5 was 639.8 mg/g, while for BV10 it was 50.7 mg/g.

15

Assessment of Modified Rice Husks for Removal of Aniline in Batch Adsorption Process: Optimization and Isotherm Study

80%

Dakhil I. H. , Naser G. F. , Ali A. H.

Journal of Ecological Engineering

|

2021

|

tom Vol. 22, nr 7

179--189

EN

The present work is aimed at investigating the capability of chemically modified rice husks (MRH) for the reduction of aniline ions from industrial wastewater. The experiments have been conducted to examine the influence of four operating parameters in the batch adsorption technique. The effect of initial concentrations of aniline (10–100) mg•L-1, MRH dose (0.1–1) g/100 ml, pH (3–9), and contact time (10–90) min has been studied. The selected range of operating factors was designed using the response surface method to establish a mathematical model that describes the adsorption process. The optimum parameters were 25 mg•L-1 initial concentration of aniline, 0.68 g MRH dose, 6.6 pH, and 70 min contact time. The point of zero charge was found equal to 6.8. The maximum removal efficiency of 84.97% was found under optimum conditions. The consistency of the mathematical model has been examined and the equilibrium results confirmed with the standard adsorption isotherm models, Langmuir and Freundlich, with a high correlation coefficient.

16

Modeling of experimental data for the adsorption of methyl orange from aqueous solution using a low cost activated carbon prepared from Prosopis juliflora

80%

Kumar M. , Tamilarasan R.

Polish Journal of Chemical Technology

|

2013

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tom 15

|

nr 2

29-39

EN

This paper presents the feasibility for the removal of methyl orange (MO) dye from aqueous solution using an activated carbon prepared from Prosopis juliflora bark. Batch adsorption experiments were carried out as a function of pH, contact time, adsorbate concentration, adsorbent dosage and temperature. The commonly applicable isotherms namely Freundlich and Langmuir equations are used for the prediction of isotherm parameters. A comparison of linear least-square method and a trial-and-error non-linear method are examined in Freundlich and Langmuir (Four forms) isotherms. The nature of adsorption isotherm feasibility was evaluated with dimensionless separation factors (RL). The dynamics of adsorption process was analyzed with Lagergren’s Pseudo-first order and Pseudo-second order kinetic equations. Thermodynamic parameters like the change in enthalpy (ΔHo), change in entropy (ΔSo) and change in Gibbs free energy (ΔGo) were evaluated and ΔGo shows a negative value whereas ΔHo shows the positive value indicating that the adsorption process was spontaneous and endothermic in nature. The functional group characterization of the adsorbent was done using Fourier transform infrared spectroscopy (FTIR). The thermal stability of activated carbon was analyzed using Thermo gravimetric analysis (TGA) and Differential thermal analysis (DTA).

17

Synthesis of Silica Microspheres Containing Iron Oxide Nanoparticles for Removal of Organic Pollutant by Adsorption and Photocatalytic Decomposition

80%

Cho Y.-S. , Sung S.

Archives of Metallurgy and Materials

|

2021

|

tom Vol. 66, iss. 3

771--776

EN

Iron oxide nanoparticles were incorporated to form composite microspheres of SiO2 and Fe2O3 for magnetic separation of the particles after adsorption or photochemical decomposition. Economic material, sodium silicate, was purified by ion exchange to prepare aqueous silicic acid solution, followed by mixing with iron oxide nanoparticles. Resulting aqueous dispersion was emulsified, and composite microspheres of SiO2 and Fe2O3 was formed from the emulsion droplets as micro-reactors during heating. Removal of methylene blue using the composite microspheres was performed by batch adsorption process. Synthesis of composite microspheres of silica containing Fe2O3 and TiO2 nanoparticles was also possible, the particles could be separated using magnets efficiently after removal of organic dye.

18

IN VITRO STUDIES OF ADSORPTION OF ERYTHROMYCIN ON CHITOSANS FROM DIETARY SUPPLEMENTS

80%

Meler J. , Grimling B. , Szcześniak M. , Biernat P.

Progress on Chemistry and Application of Chitin and its Derivatives

|

2014

|

tom 19

119-123

EN

In clinical practice, in the treatment of obesity, a plurality of natural high-molecular compounds are used, the activity of which supports weight loss. During the use of dietary supplements containing chitosan, illness sometimes develops and other therapeutic agents are applied as antibiotics The aim of our study was to determine the binding capacity of the antibiotic erythromycin depending on variable physicochemical factors, in the model of the gastrointestinal tract, by chitosans found in slimming dietary supplements Erythromycin adsorption phenomenon was studied by static and dynamic pharmaceutical model (according to the modified method of the Polish Pharmacopoeia) simulating in vitro conditions. The amount of bound drug was used to calculate the average percentage of the adsorbed dose. The results obtained show that erythromycin is adsorbed by chitosans at various pH ranges, and the binding capacity of the environment depends on the pH, viscosity and concentration of the antibiotic, as well as the chitosan and type and additional substances present in the gastrointestinal tract. The average level of the adsorption of erythromycin in the chitosan-nutrients system depends on the pH of the medium. The highest amount of adsorption was noted above pH 7 (chitosan precipitated polymer forming the emulsion-gel system).

19

Sunset Yellow sorption on weak base anion exchanger — kinetic and equilibrium studies

80%

Wawrzkiewicz M. , Wołowicz A. , Greluk M. , Hubicki Z.

Challenges of Modern Technology

|

2011

|

tom Vol. 2, no. 2

66--70

EN

The sorption equilibrium and kinetics of Sunset Yellow dye in aqueous solutions on the weak base anion exchange resin — Amberlite FPA51 were examined in this paper. The influences of phase contact time, solution pH, initial dye concentration and temperature were studied by the batch method. The amounts of dye sorbed at equilibrium changed from 9.9 to 48.7 mg/g with the increasing initial concentrations in the range 100–500 mg/L. The experimental data were analyzed by the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models of adsorption. The maximum monolayer capacity was 130.6 mg/g. The sorption free energy was equal to 14.6 kJ/mol and revealed the nature of the ion exchange mechanism in this system. The kinetic data were modelled using the pseudo-first order, pseudo-second order and intraparticle diffusion equations.

20

Dynamics of the exohedral complex composed of Ar atomic film adsorbed on the surface of single-walled carbon nanotube. Computer simulation study

80%

Dendzik Z. , Kosmider M. , Palucha S. , Brol P. , Gburski Z.

Materials Science Poland

|

2005

|

tom Vol. 23, No. 2

467--473

EN

A molecular dynamics study of the monolayer Ar atomic film adsorbed on the outer surface of single - walled (10,10) carbon nanotube has been undertaken and the vibrational spectra of this system have been determined. It was found that vibrations of the atoms in the argon film considerably influence the low - frequency vibrational dynamics of the nanotube.