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Tytuł:
Adsorption of cadmium ions on chitosan membranes: kinetics and equilibrium studies
Autorzy:
Zielińska, Katarzyna
Chostenko, Alexandre G.
Truszkowski, Stanisław
Powiązania:
https://bibliotekanauki.pl/articles/1035519.pdf
Data publikacji:
2010
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
adsorption isotherm
cadmium
chitosan
membranes
Opis:
The presence of toxic heavy metals in industrial wastewater is a serious pollution problem. The ability of chitosan membranes as an adsorbent for cadmium ions in aqueous solution was studied. Experiments were carried out as function of contact time and concentration of cadmium ions. This study has shown that chitosan is capable of removing cadmium from aqueous solution. The removal efficiency depends on reaction time and concentration of cadmium. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Equilibrium data agreed very well with the Langmuir model. The maximum adsorption capacity of the Langmuir isotherm equation was 94 mg/g and the Langmuir adsorption equilibrium constant was 1.6 × 10-3 dm3/mg at 25 °C.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2010, 15; 73-78
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetic studies on sorption of ni(ii) and cd(ii) from chloride solutions using selected acidic cation exchangers
Autorzy:
Otrembska, P.
Gega, J.
Powiązania:
https://bibliotekanauki.pl/articles/110403.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
sorption
nickel
cadmium
adsorption kinetics
adsorption isotherm
Opis:
Sorption of nickel(II) and cadmium(II) ions from chloride solutions was tested. Three different strongly acidic cation exchangers, i.e. Lewatit MonoPlus SP 112, Amberlite 200C and Amberlyst 15, were used. Effects of phase contact time, pH and initial concentration of metal ions on equilibrium and kinetics of sorption by batch methods were studied. It was showed that sorption of Ni(II) and Cd(II) could be described by the pseudo-second order equation. Experimental results data were analyzed using the Langmuir and Freundlich isotherms. Sorption of Ni(II) and Cd(II) onto investigated resins followed the Langmuir isotherm.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 1; 301-312
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of quinoline using various particle sizes anthracite: adsorption kinetics and adsorption isotherms
Autorzy:
Xu, Hongxiang
Sun, Xianfeng
Yu, Yuexian
Liu, Guowei
Ma, Liqiang
Huang, Gen
Powiązania:
https://bibliotekanauki.pl/articles/109567.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption isotherm
anthracite
particle size
quinoline adsorption kinetics
Opis:
This work provided an adsorption method of the removal of quinoline by using anthracite of various particle sizes. The characteristics of the adsorbents were analyzed by Camsizer XT for particle size analysis, FT-IR for functional groups, X-ray diffusion for mineralogical composition, Brunauer-Emmett-Teller for specific surface area and Barrett-Joyner-Halenda for pore size distribution. The average particle size of AC1-AC4 were 0.0342 mm, 0.1015 mm, 0.2103 mm and 0.3815 mm, respectively. The specific surface of the AC1-AC4 were 3.5 m2·g-1, 1.5 m2·g-1, 0.7 m2·g-1 and 0.1 m2·g-1 respectively. The adsorption capacity present a linear increase with the specific surface area increasing. To reveal the process of the adsorption, the adsorption kinetics and isotherms were performed. The kinetics data were analyzed by pseudo-first-order, pseudo-second-order and intra-particle diffusion equation using linearized correlation coefficient. Pseudo-second-order was found to best represent the kinetics data, which indicated that the adsorption of quinoline onto anthracite belongs to chemisorption. The equilibrium isotherms data were analyzed by Langmuir model and Freundlich model, the results indicated that the Freundlich model fit well for all the adsorption processes, which showed that the adsorption of quinoline onto anthracite belongs to endothermic reaction.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 196-207
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of methylene blue from aqueous solution by adsorption onto activated carbon prepared from animal bone and corncob – an agricultural waste
Autorzy:
Ezeugo, J. N. O.
Powiązania:
https://bibliotekanauki.pl/articles/1111953.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Adsorbate
Adsorbent
Adsorption
Synthetic dye
adsorption isotherm
methylene blue
Opis:
Synthetic dyes are widely used in the rubber, textiles, plastics, paper and cosmetics industries to color their products. The effectiveness of adsorption for dye removal from wastewater has made it an ideal alternative to other expensive treatment methods. This study investigates the physicochemical properties of animal-bone- (AB) and corncob- (CC) derived activated carbon on the removal of methylene blue dye. The effects of condition variables such as initial dye concentration, adsorbent dose, pH and contact time were studied. The results show that animal-bone-derived activated carbon has better potential for dye removal than does the corn cob-derived equivalent. AB revealed a higher adsorption capacity of intensity (2.40) and is of higher surface area - 500 m2g–1, while CC has adsorptive capacity of 1.25, intensity of 2.80 and surface area of 420 m2/g–1. What is more, the removal efficiency increases as adsorbent dose increases. This makes it an interesting option for dye removal from aqueous solutions of dye.
Źródło:
World News of Natural Sciences; 2018, 19; 32-44
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption and adsorption isotherm: application to corrosion inhibition studies of mild steel in 2 M HCl
Autorzy:
Abeng, F. E.
Idim, V. D.
Obono, O. E.
Magu, T. O.
Powiązania:
https://bibliotekanauki.pl/articles/1178372.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Adsorption isotherm
inhibition mechanism
mild steel
thermodynamic parameters
Opis:
Ethanollic extract of Phyllanthus amarus (EEPA) was tested as corrosion inhibitor for mild steel in 2 M HCl solution using gravimetric and gasometric methods at 303, 313, 323 K and 333 K. The results revealed that the corrosion rate increases with temperature and time. Addition of the concentration of ethanollic extract of Phyllanthus amarus to the corroding environment lowered the corrosion rate of mild steel and increased inhibition efficiency (IE %) of ethanollic extract. Inhibition efficiency was found to decreased with temperature. Fitting of the experimental data to the Arrhenius and Transition state equations revealed that the Organic constituents of the extract were physically adsorbed on the corroding surface of the steel and adsorption of ethanollic extract of Phyllanthus amarus (EEPA) on mild steel surface was found to obey the Langmuir adsorption isotherm and Freundlich adsorption isotherm and sign of the Gibb’s fee energy of the adsorption obtained suggested that inhibitor molecules have been spontaneously adsorbed onto the mild steel surface. Positive values obtained for enthalpy change indicated that the adsorption of inhibitor is endothermic.
Źródło:
World Scientific News; 2017, 77, 2; 298-313
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption behavior and XPS analysis of nonylphenol ethoxylate on low rank coal
Autorzy:
You, Xiaofang
Ma, Chuandong
Li, Zhihao
Lyu, Xianjun
Li, Lin
Powiązania:
https://bibliotekanauki.pl/articles/109627.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
low rank coal
nonylphenol ethoxylate
adsorption isotherm
adsorption kinetics
XPS
Opis:
In this work, low rank coal was used for the removal of nonylphenol ethoxylate with fifteen ethylene oxide groups (NPEO15) from aqueous solutions at different contact times, temperatures, and initial adsorbent concentrations. The adsorption isotherms showed good fit with the Langmuir equation. Maximum adsorption capacities calculated at 308, 318, and 328 K were 23.64, 29.41, and 35.71 mg g–1, respectively. The changes in the free energy of adsorption (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were calculated in order to predict the nature of adsorption. The results of the thermodynamic analysis indicated that a spontaneous process took place, driven synergistically by both enthalpy and entropy. The adsorption kinetics of NPEO15 were consistent with a pseudo-second order reaction model. XPS results showed that the oxygen functional groups on the low rank coal surface were significantly covered by NPEO15. Furthermore, while the content of C–C/C–H functional groups increased significantly, that of C–O functional groups decreased after absorption. These results clearly indicate that low rank coal is more hydrophobic and displays better floatability.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 3; 721-731
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inhibition studies of Spondias mombin L. in 0.1 HCl solution on mild steel and verification of a new temperature coefficient of inhibition efficiency equation for adsorption mechanism elucidation
Autorzy:
Magu, T. O.
Bassey, V. M.
Nyong, B. E.
Obono, O. E.
Nzeata-Ibe, N. A.
Akakuru, O. U.
Powiązania:
https://bibliotekanauki.pl/articles/1118802.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Corrosion
Freundlich adsorption isotherm
Inhibition coefficient
Inhibitor
Spondias mombin
Opis:
This research investigated the inhibition behavior of Spondias mombin leaf (SML) extracts in 0.1 M HCl solution on mild steel at various concentrations and temperatures. The result reveals that the inhibition efficiency of the extract on the mild steel sheet increases with increasing concentration of the extract and decreases with increase in temperature. Therefore, the adsorption mechanism of the extract on the mild steel surface is physical. Calculated Correlation Coefficient (R2) values show that the process follows a Freundlich adsorption isotherm. The proposed temperature coefficient equation of adsorption mechanism was found to be appropriate.
Źródło:
World News of Natural Sciences; 2017, 8; 15-26
2543-5426
Pojawia się w:
World News of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrocarbons removal from underground coal gasification water by organic adsorbents
Autorzy:
Lutynski, M.
Suponik, T.
Powiązania:
https://bibliotekanauki.pl/articles/110448.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
underground coal gasification
permeable reactive barrier
Langmuir adsorption isotherm
Opis:
The main problems in the case of the undergorund coal gasificiation process is the possible pollution of surrounding aquifers. The underground gasification cavity is a source of both gaseous and liquid pollutants and these are mainly aromatic hydrocarbons, phenols, heavy metals and others. In order to prevent underground water from pollution a permeable reactive barrier was proposed. The filling was granulated activated carbon and SPILL-SORB (peat) – two commonly available sorbents adequate for hydrocarbons removal. The wastewater (synthetic solution which simulated groundwater contaminated with the UCG products) was prepared by mixing distilled water with desired amounts of substances such as phenols, benzene, toluene, xylene, naphthalene etc. Batch tests were performed in order to measure sorption of phenols and benzene from the post-UCG water on the mentioned sorbents. Experimental results were fitted with linear and non-linear Freundlich and Langmuir isotherm models. The obtained data showed that removal of phenols and benzene in case of GAC was much more efficient. However, sorption was lower than in the case of literature data and can be explained by complex composition of the solution and pre-treatment of the samples. The Langmuir model gave a better fit in the case of GAC, whereas Freundlich isotherm model was matching the data better in case of SPILL-SORB.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 1; 289-298
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inhibition and adsorption of oil extract of Balanites aegyptiaca seeds on the corrosion of mild steel in hydrochloric acid environment
Autorzy:
Iroha, Nkem B.
Hamilton-Amachree, Akens
Powiązania:
https://bibliotekanauki.pl/articles/1075452.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Balanites aegyptiaca
Mild steel
Temkin adsorption isotherm
corrosion
inhibition
Opis:
The efficiency of oil extract of Balanites aegyptiaca seeds on the inhibition of mild steel corrosion in 1 M HCl has been investigated using gravimetric and electrochemical (Potentiodynamic Polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS)) techniques. Results obtained show that Balanites aegyptiaca (BA) oil extract inhibited the acid corrosion of mild steel. Polarization technique showed that BA oil extract acted as mixed-type inhibitor in 1 M HCl solution. The impedance technique reveals that charge-transfer process controls the corrosion of mild steel. The inhibiting action of BA oil extract was attributed to their adsorption on the mild steel surface and the formation of dense protective layer which increased by increasing their concentration. BA inhibits the corrosion of mild steel by an adsorption mechanism, which follows Temkin adsorption isotherm. Physical adsorption mechanism has been proposed for the inhibitory action of BA oil extract. The protective film formed on the surface was confirmed by scanning electron microscopy (SEM).
Źródło:
World Scientific News; 2019, 126; 183-197
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption equilibrium of carbon dioxide on zeolite 1X at high pressures
Autorzy:
Zabielska, K.
Aleksandrzak, T.
Gabruś, E.
Powiązania:
https://bibliotekanauki.pl/articles/185520.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
carbon dioxide
zeolite 13X
adsorption equilibrium
adsorption isotherm
zeolit 13X
Opis:
Carbon dioxide (CO2) is a compound responsible for the greenhouse effect. One of the methods of CO2 capture from the gas stream is adsorption process. In this paper, the adsorption equilibrium isotherms of CO2 on zeolite 13X were measured at different temperatures (293.15 K, 303.15 K, 313.15 K, 323.15 K, 333.15 K, 348.15 K, 373.15 K, 393.15 K) and under pressures up to 2 MPa. These data were obtained using an Intelligent Gravimetric Analyzer (IGA-002, Hiden Isochema, UK). Selected multitemperature adsorption isotherm equations, namely Toth, Langmuir–Freundlich, and, Langmuir were correlated with experimental data.
Źródło:
Chemical and Process Engineering; 2018, 39, 3; 309--321
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ obecności wybranych SPC na adsorpcję jonów Cr(III) i Cr(VI)
The influence presence of selected spc for absorption Cr (III) and Cr (VI)
Autorzy:
Lach, J.
Powiązania:
https://bibliotekanauki.pl/articles/297450.pdf
Data publikacji:
2015
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
chrom
substancje powierzchniowo czynne
adsorpcja
izotermy adsorpcji
chromium
surfactants
adsorption
adsorption isotherm
Opis:
Przeprowadzono adsorpcję kationów chromu trójwartościowego i anionów chromu sześciowartościowego na węglu ROW 08 Supra z roztworów jednoskładnikowych i dwuskładnikowych zawierających substancje powierzchniowo czynne (SPC). Przeanalizowano znaczenie obecności w roztworze kationowych, anionowych i niejonowych SPC (2 związki z każdej grupy na adsorpcję jonów Cr(III) i Cr(VI). Stwierdzono pozytywny wpływ substancji powierzchniowo czynnych w przypadku, gdy miały one przeciwny ładunek w stosunku do usuwanego jonu chromu (kationowe SPC podczas adsorpcji anionów Cr(VI), anionowe SPC podczas adsorpcji kationów Cr(III)). Jest to spowodowane najprawdopodobniej powstawaniem nowych centrów aktywnych na powierzchni węgli aktywnych w wyniku adsorpcji jonowych SPC. Obecność w roztworze niejonowych SPC oraz jonowych o takim samym znaku ładunku jak adsorbowane jony Cr(III) lub Cr(VI) powoduje zmniejszenie pojemności adsorpcyjnej węgla. Jest to spowodowane blokowaniem jonów oraz konkurencyjnością między jonami chromu a SPC. Do opisu wyników adsorpcji użyto modeli Langmuira, Freundlicha, Temkina i Dubinina-Radushkevicha. Wszystkie te izotermy opisują uzyskane rezultaty procesu z wysokimi wartościami współczynnika korelacji.
The present study reports the results of the adsorption of trivalent chromium cations and hexavalent chromium anions on ROW 08 Supra carbon from single solute and bisolute solutions containing surfactants. The roles of the cationic, anionic and non-ionic (2 compounds per group) surfactants’ presence in the solution were analysed with reference to the adsorption of Cr(III) and Cr(VI) ions. The positive impact of surfactants was observed in the cases when their charge was the opposite to the removed chromium ion (cationic surfactant during the adsorption of Cr(VI) anions, anionic surfactant during the adsorption of Cr(III) cations). Most probably it is the result of new active cents on the surface of active carbons caused by ionic surfactant adsorptions. The presence in the solution of non-ionic and ionic surfactants of the same charge as the adsorbed Cr(III) and Cr(VI) ions results in the decrease of carbon adsorption surface. It is caused by ion blocking and competition between the chromium ions and surfactants. The Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models were used for the adsorption result descriptions. All the isotherms of high correlation coefficient values describe the obtained results of the process.
Źródło:
Inżynieria i Ochrona Środowiska; 2015, 18, 4; 537-547
1505-3695
2391-7253
Pojawia się w:
Inżynieria i Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of adsorption isotherm models for the biosorption of chromium using cherry leaves (Muntingia calabura L.)
Autorzy:
Aathithya, R.
Sowparnika, J.R.
Balakrishnan, V.
Powiązania:
https://bibliotekanauki.pl/articles/11799.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
determination
adsorption isotherm model
biosorption
chromium
cherry
leaf
Muntingia calabura
Opis:
Contaminations of industrial metals into the river possess major threat to environment. Chromium is a heavy metal which has the wide applications in tannery and electroplating industries. Above the permitted level of Chromium(VI) into surface water leads to severe health hazards. Therefore, biosorption is a technology used for the sorption of heavy metal. In this present study adsorption isotherm models was studied for the biosorption of chromium by cherry leaves. From the adsorption isotherms it was found that the experimental data fits well with the Langmuir isotherm than the Freundlich isotherm. The monolayer capacity Qm was fond to be 11.98 mg/l and the adsorption affinity was found to be positive which indicates the efficient biosorption of chromium.
Źródło:
International Letters of Natural Sciences; 2014, 20
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fundamental study of monovalent and divalent ions on froth properties in the presence of terpenic oil
Autorzy:
Li, Yubiao
Wang, Hongduo
Li, Wanqing
Song, Shaoxian
Powiązania:
https://bibliotekanauki.pl/articles/110301.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
surface tension
froth stability
dynamic foamability index
Gibbs adsorption isotherm
Opis:
In order to minimize fresh water usage, much attention has been paid to the flotation using saline or sea water. However, the effects of various ions in these waters on froth properties in flotation are not fully understood. In this study, the effects of electrolyte solutions containing NaCl, KCl, CaCl2, and MgCl2 at different concentrations in the presence of terpenic oil as a frother were investigated on froth performance, dynamic froth stability (DFS). It was found that KCl had the best synergistic effects with terpenic oil in reducing the solution surface tension. In the presence of terpenic oil, the DFS and half-life time were reduced with the increased ion concentration. Dynamics foamability index measurements (DFI) confirmed that the increased ion concentration increased the foamability, as frother did. In addition, Gibbs adsorption isotherm suggested that the amount of terpenic oil adsorbed at the gas-liquid interface was increased with the increased ion concentration. This study therefore indicated that the presence of ions can reduce the froth stability but not decline foamability due to terpenic oil, enlighting the application of saline or sea water in defoaming process in flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 3; 643-654
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ liczby atomów chloru w cząsteczkach kwasów chlorofenoksyoctowych na ich adsorpcję z roztworów wodnych na węglu aktywnym
Influence of the number of chlorine atoms in the molecules of chlorophenoxyacetic acids on its adsorption from aqueous solutions on activated carbon
Autorzy:
Kuśmierek, K.
Świątkowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/236430.pdf
Data publikacji:
2013
Wydawca:
Polskie Zrzeszenie Inżynierów i Techników Sanitarnych
Tematy:
herbicides
phenoxyacetic acids
adsorption kinetics
adsorption isotherm
herbicydy
kwasy fenoksyoctowe
kinetyka adsorpcji
izoterma adsorpcji
Opis:
Three phenoxyacetic acids of various number of chlorine atoms in the molecule (PA, 4-CPA, 2,4-D) were selected to adsorption experiments. Adsorption of these compounds from aqueous solutions has been studied using commercial activated carbon F300 (Chemviron). The kinetic data were examined with the pseudo-first-order and pseudo-second-order models, and were found to follow closely the pseudo-second-order kinetic model. With increase in the initial solution concentration rate constants k2 diminish for each adsorbate and with increase in the number of Cl atoms in phenoxyacetic acid molecule rate constants k2 decrease for each initial solution concentration. Adsorption equilibrium data were analyzed and were fitted well using Freundlich isotherm in the studied concentration range. With increase in the number of Cl atoms in phenoxyacetic acid molecules the Freundlich equation constants KF and n decrease. Presence of electrolyte (Na2SO4) in aqueous solutions of phenoxyacids enhances their adsorption.
Do badań adsorpcyjnych wybrano trzy kwasy fenoksyoctowe o różnej liczbie atomów chloru w cząsteczce (PA, 4-CPA, 2,4-D). Adsorpcję tych związków z roztworów wodnych badano stosując handlowy węgiel aktywny F-300 (Chemviron). Dane kinetyczne analizowano z użyciem modeli pseudo-pierwszego i pseudo-drugiego rzędu i stwierdzono, że dobrze spełniają kinetyczny model pseudo-drugiego rzędu. Wraz ze wzrostem początkowego stężenia roztworu wartości stałej szybkości k2 zmniejszały się w przypadku każdego adsorbatu. Także wraz ze wzrostem liczby atomów chloru w cząsteczce kwasu fenoksyoctowego zmniejszały się wartości stałej szybkości k2 przy każdym stężeniu początkowym adsorbatu. Analizowano także dane adsorpcji w funkcji równowagowego stężenia roztworu. Stwierdzono, że w zakresie stosowanych stężeń, adsorpcja była dobrze opisywana przy użyciu izotermy Freundlicha. Wraz ze wzrostem liczby atomów chloru w cząsteczce kwasu fenoksyoctowego wartości stałych równania Freundlicha (KF i n) malały. Stwierdzono też, obecność elektrolitu (Na2SO4) w roztworach fenoksykwasów powodowała wzrost ich adsorpcji.
Źródło:
Ochrona Środowiska; 2013, 35, 1; 47-50
1230-6169
Pojawia się w:
Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza porowatości materiałów węglowych z jednoczesnym wykorzystaniem danych adsorpcji azotu i dwutlenku węgla
Analysis of carbon materials porosity by simultaneous use of adsorption data for nitrogen and carbon dioxide
Autorzy:
Choma, J.
Stachurska, K.
Kloske, M.
Dziura, A.
Jagiełło, J.
Jaroniec, M.
Powiązania:
https://bibliotekanauki.pl/articles/236332.pdf
Data publikacji:
2017
Wydawca:
Polskie Zrzeszenie Inżynierów i Techników Sanitarnych
Tematy:
adsorption
active carbon
adsorption isotherm
N2
CO2
pore size distribution
adsorpcja
węgiel aktywny
izoterma adsorpcji
funkcja rozkładu objętości porów
Opis:
Knowledge of porous structure of carbons, including ultramicropores, micropores and mesopores, is of great importance in application of these materials for different purposes. Usually, their characteristics includes determination of specific surface area, pore volume and pore size distribution. The latter is often calculated on the basis of experimental nitrogen adsorption isotherm at –196 oC for relative pressures ranging from about 10–7 up to 1.0. It has been determined that experimental CO2 adsorption isotherm alone (0 oC, up to 1 atm), or together with N2 adsorption isotherm, may be applied to yield interesting results of pore size distributions. For illustration purposes, the pore size distributions were calculated for the three polymer-obtained microporous carbons and one ordered mesoporous carbon obtained by soft templating. The calculations were performed using the latest version of the SAIEUS program based on the Nonlinear Method in the Density Functional Theory (NLDFT) for the non-uniformly porous carbon materials. It has been shown that the simultaneous use of N2 and CO2 adsorption isotherms for calculation of the pore size distribution allows for a realistic assessment of carbon materials porosity.
Wiedza o strukturze porowatej węgli aktywnych, w tym o ultramikroporach, mikroporach i mezoporach, ma zasadnicze znaczenie w zastosowaniu tych materiałów do różnych celów. Zazwyczaj charakterystyka tych materiałów obejmuje wyznaczenie powierzchni właściwej, objętości porów i funkcji rozkładu objętości porów. Tę ostatnią funkcję wyznacza się na podstawie doświadczalnej izotermy adsorpcji azotu w temperaturze –196°C w przedziale ciśnień względnych od około 10–7 do około 1,0. W pracy wykazano, że interesujące wyniki dotyczące funkcji rozkładu objętości porów można otrzymać, jeśli wykorzystuje się doświadczalną izotermę adsorpcji CO2 (w temp. 0°C i ciśnieniu do 1 atm) lub jednocześnie izotermy adsorpcji N2 i CO2. W celu ilustracji rozwiązania tego problemu, w pracy obliczono funkcje rozkładu objętości porów trzech mikroporowatych węgli otrzymanych z prekursorów polimerowych oraz jednego uporządkowanego węgla mezoporowatego otrzymanego metodą miękkiego odwzorowania. Obliczenia funkcji rozkładu wykonano za pomocą najnowszej wersji programu SAIEUS, stosując metodę z teorii funkcjonału gęstości (NLDFT) w przypadku niejednorodnych, porowatych materiałów węglowych. Wykazano, że jednoczesne wykorzystanie izoterm adsorpcji N2 i CO2 do wyznaczania funkcji rozkładu porów pozwala na rzeczywistą ocenę porowatości materiałów węglowych.
Źródło:
Ochrona Środowiska; 2017, 39, 3; 4-7
1230-6169
Pojawia się w:
Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 65

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