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Wyszukujesz frazę "water adsorption" wg kryterium: Temat


Wyświetlanie 1-14 z 14
Tytuł:
Density functional theory study of H2O adsorption on different sphalerite surfaces
Autorzy:
Deng, Zheng-bin
Tong, Xiong
Huang, Ling-yun
Xie, Xian
Powiązania:
https://bibliotekanauki.pl/articles/110593.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
density functional theory
sphalerite
water adsorption
hydrophobicity
Opis:
Effects of In, Ge, Fe substitution in the lattice of sphalerite on wettability were usually ignored, therefore the optimal flotation condition could be difficult to find due to lacking of sufficient theoretical study on water adsorption, resulting lower recoveries of different sphalerites. Adsorption of H2O on different sphalerite surfaces was studied using density functional theory (DFT) method. All computational models were built in a vacuum environment to eliminate the effects of oxygen and other factors. H2O molecule prefers to stay with ideal sphalerite, indium-beard sphalerite, germanium-beard sphalerite and marmatite surfaces rather than water. Compared with ideal sphalerite surface, Fe atom improves the hydrophilicity of surface, while In and Ge atoms reduce the hydrophilicity.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 82-88
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First-principles study on the adsorption structure of water molecules on a pyrite (100) surface
Autorzy:
Liu, Yingchao
Chen, Jianhua
Li, Yuqiong
Zhang, Junjie
Kang, Duan
Powiązania:
https://bibliotekanauki.pl/articles/1447970.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
pyrite
water molecules
adsorption
Opis:
The hydration structure of water molecule adsorption at different coverages of a monolayer on a pyrite (100) surface were simulated using the density functional theory (DFT) method. The results demonstrate that the Fe-O interaction weakens and the adsorption energy per water molecule decreases with increasing water coverage, except at a monolayer coverage of 12/12 (i.e., full coverage). H-S and H-O hydrogen bonds were formed on the nearest surface layer. When large amounts of water molecules adsorb onto the surface, the adsorbed water molecules can be divided into three layers: the layer nearest to the surface, the second nearest to the surface, and the layer farthest from the surface. The thickness of the former two layers is approximately 5.5 Å. The three layers have water densities of 1.12 g/cm3, 1.08 g/cm3, and 0.95 g/cm3, respectively, suggesting that there is a strong interaction between the pyrite surface and water molecules and the influence of surface structure on water adsorption reaches a distance of more than 10 Å. Dynamics simulations suggest that the water molecules close to the mineral surfaces are in an orderly arrangement while those far from the surface are disordered.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 2; 121-130
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of saline water on the synergistic interaction between diesel and Triton X-100 in the flotation of oxidized coal
Autorzy:
Chang, Ziyong
Diallo, Lancine
Feng, Bo
Powiązania:
https://bibliotekanauki.pl/articles/1448948.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
saline water
surfactants
adsorption
flotation
coal oxidation
Opis:
In this study, the effect of medium saline water on the synergistic interaction between diesel and Triton X-100 in the flotation of oxidized coal was investigated. The results showed that the flotation yield of oxidized coal in saline water was higher than that in de-ionized (DI) water due to the promotion of diesel adsorption, which was attributed to the screening of electrostatic repulsion between diesel droplets and coal particles in saline water. Meanwhile, the flotation of oxidized coal could be significantly improved when Triton X-100 was added with diesel as a composite collector, and less Triton X-100 was required in saline water than that in DI water to achieve the same true flotation yield, indicating that saline water could increase the effectiveness of Triton X-100 in improving oxidized coal flotation. A mechanism study revealed that Triton X-100 was able to promote diesel adsorption on oxidized coal through emulsification, thus increasing the surface hydrophobicity of oxidized coal through hydrogen bonding between the headgroups of Triton X-100 and the oxygenated groups on coal surfaces. The non-ionic characteristic of Triton X-100 ensured its capability of enhancing oxidized coal flotation in both DI water and saline water.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 1; 216-225
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of azathioprine on the parameters of double Hg/chlorate(VII) interface layer in the presence of nonionic surfactants
Autorzy:
Kaliszczak, Waldemar
Grochowski, Mariusz
Nosal-Wiercińska, Agnieszka
Brycht, Mariola
Checinska-Majak, Dorota
Gołębiowska, Beata
Powiązania:
https://bibliotekanauki.pl/articles/109820.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
azathioprine
mixed adsorption layers
Triton X-100
Tween 80
adsorption parameters
water activity
Opis:
The mixed adsorption of azathioprine and Triton X-100 or Tween 80 at the mercury/ chlorates (VII) interface wasdescribed. The differential capacitance of the double layer Cd at the Hg/ basic electrolyte interface was measured using the electrochemical impedance spectroscopy. The potential of zero charge Ez wasdetermined applying streaming mercury electrode and the surface tension at the potential of zero charge γz was measured by the method of the highest pressure inside the mercury drop. The changes of determined parameters in the function of the supporting electrolyte concentration point with the participation of ClO4-ions in the adsorption process, as well as the electrostatic interactions between the dipoles of H2O and azathioprine–Triton X-100 or azathioprine–Tween 80 in the double layer are shown.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 6; 1350-1356
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monitoring of contamination of coal processing plants and environmental waters using bubble velocity measurements – advantages and limitations
Autorzy:
Zawala, J.
Malysa, E.
Krzan, M.
Malysa, K.
Powiązania:
https://bibliotekanauki.pl/articles/110915.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bubble velocity
water purity
surface active contaminants
method detection
adsorption layer
Opis:
The paper presents fundamentals of a simple physicochemical method (SPMD) and analysis of results obtained when the method was applied for detection of organic contaminations (surface-active substances SAS) in samples of environmental and industrial waters. The method is based on measurements of variations of air bubble local velocities, which can be significantly changed in presence of surface-active contaminants. Lowering of the bubble velocity is a consequence of a motion induced dynamic adsorption layer (DAL) formed over surface of the rising bubble. The DAL formation retards the surface fluidity and the bubble rising velocity can be lowered by over 50% when the bubble surface is completely immobilized. We showed that the SPMD is a very sensitive tool (detection limit even below 1 ppm) for detection of various kinds of surface-active substances (ionic, non-ionic) in water samples. On the basis of results obtained using precise laboratory set-up, an accuracy of the SPMD is discussed. Moreover, effect of inert electrolyte addition on the bubble velocity lowering and value of detection limit of the SPMD is discussed. Simple approach, enabling quantitative analysis of the surface-active contaminants in samples collected, based on “equivalent concentrations” determination, is proposed. Results obtained for industrial (Jankowice and Knurow coal processing plants, Jaslo Refinery channel) and environmental waters (Wisloka and Ropa river) are used for detailed analysis and critical discussion of advantages and limitations of the SPMD.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 1; 143-157
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption of hexane and cyclohexane vapours at the water drop surface
Autorzy:
Miller, R.
Aksenenko, E. V.
Kovalchuk, V. I.
Tarasevich, Y. I.
Fainerman, V. B.
Powiązania:
https://bibliotekanauki.pl/articles/110244.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
water-heptane vapour interface
drop profile analysis tensiometry
dynamic surface tension
adsorption kinetics
Opis:
The dependence of the dynamic surface tension of water at the interface with saturated hexane and cyclohexane vapours was measured by the drop profile analysis method. The surface tension for the adsorption layers of cyclohexane at different temperatures was compared with the results reported earlier for the adsorption of hexane and other alkanes from the vapour phase on water drops. It is shown that cyclohexane is adsorbed significantly slower than the adsorption of hexane occurs, and is characterised by a much larger induction time. The error in the drop radius measurements at 40 ºC attains 45 m. The experimental rheologic characteristics of the adsorbed layers are studied and the results are compared with the model developed to describe an adsorption process governed by a kinetic mechanism.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 1; 54-62
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of reactive blue 29 dye by adsorption on modified chitosan in the presence of hydrogen peroxide
Autorzy:
Naghizadeh, A.
Nabizadeh, R.
Powiązania:
https://bibliotekanauki.pl/articles/208197.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption isotherms
copper compounds
isotherms
sewage
adsorption capacities
Langmuir isotherm
natural water systems
izotermy adsorpcji
związki miedzi
ścieki
izotermy kanalizacyjne
ścieki przemysłowe
izoterma Langmuira
Opis:
Industrial effluents that carry dyestuff into natural water systems are serious environmental concern. Complex aromatic structures of dyes make them more stable and more difficult to remove from the effluents discharged into water bodies. In the present study, removal of reactive blue 29 dye with chitosan and modified chitosan with Cu complexes from aqueous solution was investigated in a batch adsorption system with respect to the changes in the contact time, pH of solution and chitosan dosage. Adsorption isotherms of the dye onto chitosan were also studied. The results revealed that the adsorption capacity of chitosan with Cu complexes is lower than that of chitosan without Cu complexes. Also effect of H2O2 on adsorption when we used chitosan without Cu complexes is more considerable. The results also demonstrated that adsorption capacity of reactive blue 29 dye on chitosan was higher at lower pHs. Finally, the Langmuir isotherm showed the best conformity to the equilibrium data.
Źródło:
Environment Protection Engineering; 2016, 42, 1; 149-168
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption of Pb(II) using novel Pleurotus sajor-caju and sunflower hybrid biosorbent
Autorzy:
Majeed, A.
Jilani, M. I.
Nadeem, R.
Hanif, M. A.
Ansari, T. M.
Powiązania:
https://bibliotekanauki.pl/articles/206884.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ołów
adsorpcja
biomasa
zanieczyszczenie wody
biosorbent
Pleurotus sajor caju
grzyby
lead
adsorption
biomass
water pollution
biosorbents
Opis:
The present study was focused on the technical feasibility of using immobilized hybrid biomass of Pleurotos sajor-caju and sunflower for Pb(II) removal from the contaminated water. After preliminary evaluation, it was found that immobilized hybrid biomass of Pleurotos sajor-caju and sun-flower effectively removed Pb(II) from wastewater at pH 4.5. The effect of various experimental parameters on Pb(II) uptake by hybrid biosorbent was systematically evaluated in a batch biosorption system. The optimized biosorbent dose, contact time, initial metal concentration and temperature were 0.05 g/100 cm 3, 180 min, 800 mg/dm3 and 60 °C. Dynamics of the adsorption process were studied, and the values of rate constants of pseudo first order and pseudo second order kinetic models were calculated. Equilibrium isotherms for the adsorption of Pb(II) were analyzed by the Langmuir and Freundlich isotherm models. The sorption of Pb(II) followed the pseudo second order kinetic model. The Langmuir sorption isotherm fitted well to Pb(II) concentration data. The results revealed that this new hybrid biosorbent system was a promising candidate for eliminating Pb(II) from contaminated aquatic environment.
Źródło:
Environment Protection Engineering; 2014, 40, 2; 5-15
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of modified maize hull for removal of Cu(II) ions from aqueous solutions
Autorzy:
Ghasemi, S. M.
Mohseni-Bandpei, A.
Ghaderpoori, M.
Fakhri, Y.
Keramati, H.
Taghavi, M.
Moradi, B.
Karimyan, K.
Powiązania:
https://bibliotekanauki.pl/articles/208248.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
heavy metal ions
waste water
Cu(II)
ions
adsorption
biomass
jony metali ciężkich
ścieki
biomasa
adsorpcja
Opis:
Discharge of industrial waste containing heavy metals to the environment is a main concern because of their toxicity to many life forms. Adsorption process is one of the conventional methods in order to adsorb heavy metals from wastewater effluents. Therefore, the removal of Cu(II) from aquatic solutions using modified maize hull was investigated. All experiments were performed in batch conditions. The residual Cu(II) concentration was measured by AAS. Upon increasing the adsorbent dosage, pH, and contact time and decreasing Cu(II) concentration, the removal efficiency of Cu(II) ions increased. In optimum conditions, 50% of copper was removed by modified maize hull. The experimental data were best fitted by the Langmuir type 2 model and the adsorption kinetic model followed a pseudo-second order type 1 model. It seems that the use of the modified maize hull to remove Cu(II) ions is very suitable, low-cost, and efficient.
Źródło:
Environment Protection Engineering; 2017, 43, 4; 93-103
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient phosphate removal in swine wastewatewater using Fe-Mn-modified pyro/hydrochar from swine manure
Autorzy:
Zhu, Fanglun
Zhang, Cheng
Shan, Shengdao
Yuan, Wenqiao
Pawłowski, Artur
Song, Chengfang
Cao, Yucheng
Li, Yongfu
Wangj, Junjie
Qian, Jinyao
Powiązania:
https://bibliotekanauki.pl/articles/2032865.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phosphate adsorption
pig
water eutrophication
biochar
swine manure
adsorpcja fosforanów
trzoda chlewna
eutrofizacja wód
biowęgiel
obornik świński
Opis:
Phosphorus in wastewater is one of the main causes of water eutrophication. Phosphorus removal from swine wastewater is always a challenge. To achieve on-site recycling of swine farm waste, the low-cost pyro/hydrochars and their Fe-Mn-modified form were prepared from swine manure as an efficient adsorbent for phosphate removal. The results showed that the phosphate removal efficiency of unmodified pyro/hydrochars was less than 7.77%, which was significantly increased to 58.21–83.76% for the Fe-Mn-modified-pyro/hydrochars. The maximum adsorption capacity of pyrochar was found on the Fe-Mn-modified-pyrochar (PC-600M) with a surface area of 102.03 m2/g and a micropore volume of 0.25 cm3/g. The PC-600M exhibited high adsorption capacity (26.07 mg/g) in a low concentration of phosphate (50 mg/dm3), and its removal efficiency reached up to 83.76% within 24 hours. Furthermore, the adsorption of phosphate on biochars without modification (HC-210 and PC-600) was validated using a first-order kinetic model, and the adsorption of phosphate on modified biochars (HC-210M and PC-600M) was well described by the second-order kinetic model and Langmuir isotherm. In addition, there is no significant difference in the adsorption of phosphorus between pyrochars and hydrochars, but the preparation cost of hydrochars is lower than that of pyrochars. It was confirmed that the low-cost Fe-Mn-modified pyro/hydrochar from swine manure had potential for efficient phosphate removal in wastewater treatment and would facilitate value-added utilization of swine manure.
Źródło:
Environment Protection Engineering; 2021, 47, 3; 83-101
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential of pumice modified with iron(III) for copper removal from aqueous solutions
Autorzy:
Guler, U. A.
Cebeci, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/207939.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption capacities
copper concentration
ion exchange
iron oxides
water treatment
zdolność adsorpcji
stężenie miedzi
wymiana jonowa
tlenki żelaza
uzdatnianie wody
Opis:
Iron-modified pumice (Fe-P) was prepared by the ion-exchange method using natural pumice from Kayseri, Turkey at room temperature without calcination. SEM, FTIR, XRD, and S-BET measurement were used to investigate the copper removal mechanism. The results show that the SBET of the pumice increased from 11.88 m2/g to 21.01 m2/g after iron modification. The effects of pH, contact time, initial copper concentration, temperature, and various cations (Na+, K+, Ca2+, Mg2+ and Al3+) at various pH were investigated in batch experiments. More than 92% of Cu(II) was removed after 180 min. Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherm models were applied to the equilibrium data at 298, 308 and 318 K. The maximum adsorption capacity at 298, 308 and 318 K was found to be 21.52, 19.48, and 19.67 mg/g, respectively. The kinetics of copper on Fe-P was best described by the pseudo-second order kinetic model. The negative values of free energy change and enthalpy change indicated that the adsorption process was feasible, spontaneous and exothermic.
Źródło:
Environment Protection Engineering; 2017, 43, 3; 165-180
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of hexavalent chromium from aqueous solution by adsorption on γ-alumina nanoparticles
Autorzy:
Golestanifar, H.
Haibati, B.
Amini, H.
Dehghani, M. H.
Asadi, A.
Powiązania:
https://bibliotekanauki.pl/articles/207945.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption
alumina
aluminum
chemicals removal
water treatment
chromium
chromium compounds
nanoparticles
sorption
alumina nanoparticles
hexavalent chromium
adsorpcja
aluminium
usuwanie chemikaliów
uzdatnianie wody
chrom
związki chromu
nanocząstki
sorpcja
nanocząstki tlenku glinu
chrom sześciowartościowy
Opis:
The use of γ-alumina (γ-Al2O3) nanoparticles as adsorbent to remove Cr(VI) from aqueous solution was investigated using batch experiments. Adsorption experiments were carried out for various initial doses of Al2O3, initial concentrations of chromium(VI), contact times and pH. The structure and morphology of the sorbent was characterized by XRD, SEM, and TEM techniques. Results demonstrated that the removal efficiency of chromium(VI) was increased by increasing the contact time, initial concentration, and pH. The results of the study showed that adsorption of chromium by γ-alumina nanoparticles reached equilibrium after 60 min and after that a little change of chromium removal efficiency was observed. Furthermore, kinetics of chromium sorption was well fitted by pseudo-second order kinetic model, and well explained by the Freundlich isotherm (R2 > 0.992). Overall, alumina nanoparticles recognized as an effective sorbent to remove chromium(VI) from aqueous solutions.
Źródło:
Environment Protection Engineering; 2015, 41, 2; 133-145
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Equilibrium and kinetic studies on the removal of heavy metal ions with natural low-cost adsorbents
Autorzy:
Varank, G.
Demir, A.
Bilgili, M. S.
Top, S.
Sekman, E.
Yazici, S.
Erkan, H. S.
Powiązania:
https://bibliotekanauki.pl/articles/207257.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorbents
adsorption
bentonite
dyes
heavy metals
kinetics
metal ions
water treatment
heavy metal removal
heavy metal ions
heavy metals ions removal
adsorbenty
adsorpcja
bentonit
barwniki
metale ciężkie
kinetyka
jony metali
usuwanie jonów metali ciężkich
uzdatnianie wody
Opis:
Adsorption isotherms and kinetics of the removal of heavy metal ions (Ni, Pb, Zn) from aqueous solutions by natural adsorbents (zeolite, bentonite, clay) were investigated in a lab-scale batch study. The effect of various parameters such as adsorbent dosage, initial concentration of heavy metal ions, temperature, and agitation time were studied to optimise the conditions. Under those optimized conditions (180 rpm agitation rate, 120 min agitation time, pH 4.0, 298 K, 100 mg/dm3 initial adsorbate concentration), the removal percentages of heavy metal ions for natural adsorbents have been determined. The adsorption mechanisms and characteristic parameters of the process were analyzed by two and three parameter isotherm models (Langmuir, Freundlich, Temkin, Redlich-Peterson, Toth and Sips), and kinetic models (Lagergren's pseudo-first order, Ho and McKay's pseudo-second order). Adsorption thermodynamics of heavy metal ions (changes of standard enthalpy, entropy and free energy) on zeolite, bentonite and clay were also studied at 298,318 and 338 K.
Źródło:
Environment Protection Engineering; 2014, 40, 3; 43-61
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption kinetics of fluoride on bone char and its regeneration
Autorzy:
Hu, J.
Wu, D.
Rao, R.
Liu, R.
Lai, W.
Powiązania:
https://bibliotekanauki.pl/articles/206892.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chlorine compounds
fluorine compounds
ions
sodium compounds
sulfur compounds
adsorption kinetics
chemical reaction equilibrium
correlation coefficient
Freundlich equation
optimal conditions
layered double hydroxides
aqueous-solution
drinking water
equilibrium
adsorbent
związki chloru
związki fluoru
jod
związki sodu
związki siarki
kinetyka adsorpcji
równowaga reakcji chemicznej
współczynnik korelacji
równanie Freundlicha
woda pitna
równanie Langmuira
Opis:
The adsorbent of bone char (BC), produced from the pyrolysis of crushed animal bones, was dominated by the mesopores of the Brunauer Emmett Teller (BET) surface area. The optimal condition for defluoridation with BC was a pH level near 5.0. Chloride and nitrate ions could increase fluoride adsorption capacity in contrast with the effect of sulfate and carbonate ions. The interchangeability between fluoride and hydroxyl groups on BC sorbent was proved by the Fourier transform infrared spectroscopy. Langmuir equation had a better correlation coefficient than the Freundlich equation at various temperatures. Thermodynamic parameters such as Delta G degrees, Delta H degrees, Delta S degrees, Ea and S*, have been calculated to describe the nature of fluoride adsorption onto BC. Negative Delta G degrees and Delta H degrees values at various temperatures indicate a spontaneous process, and its exothermic effect, respectively. However, a positive Delta S degrees value represents an increasing process for entropy. The E-a and S* values ranging from 5 to 40 kj.mol-1 and 0 to 1, respectively, demonstrated that the adsorption is dominated by physical process, although the adsorption kinetic process was involved external diffusion, intraparticle diffusion and chemical reaction equilibrium stage. A high concentration of NaOH solution increases efficiency of removing adsorbed F- ions from the BC surface.
Źródło:
Environment Protection Engineering; 2017, 43, 3; 93-112
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-14 z 14

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