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Wyszukujesz frazę "adsorption model" wg kryterium: Temat


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Tytuł:
Adsorpcja dwufunkcyjnych labilnych surfaktantów kationowych na granicy faz ciecz/gaz : opis za pomocą modelu kwazi-dwuwymiarowego elektrolitu
Adsorption of dicephalic labile cationic surfactants at liquid/gas interfaces : surface quasi-two-dimensional electrolyte model descripton
Autorzy:
Frąckowiak, Renata
Para, Grażyna
Lamch, Łukasz
Szyk-Warszyńska, Lilianna
Wilk, Kazimiera A.
Warszyński, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2057918.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
kationowe surfaktanty wielofunkcyjne
surfaktanty chemodegradowalne
adsorpcja
napięcie powierzchniowe
model adsorpcji
multifunctional cationic surfactants
chemodegradable surfactants
adsorption
surface tension
adsorption model
Opis:
There is an increasing interest in surfactants that comprise a linkage that breaks down in a controlled way. The most known examples of the cleavage mechanism include acid or alkaline hydrolysis, UV irradiation, enzymatic or heat decomposition. For practical reasons, the labile grouping can be inserted between the hydrophobic tail of the surfactant and the polar head group. Chemically and/or enzymatically induced cleavage of this labile bond would cause the separation of the polar part and the hydrophobic tail and, consequently, change of surface activity, an event usually referred to as the primary degradation of the surfactant. Dicephalic labile cationic surfactants belong to the class of surface active compounds with many potential applications often associated with their biological activity for a wide range of bacteria, viruses, fungi, or algae. Thus, they can be used in disinfecting agents or for protecting against the occurrence of these microorganisms. They adsorb well on negatively charged surfaces, which can be used in the treatment of fabrics. Due to excellent antistatic properties, they can be used for the final rinsing of fabrics, especially synthetic ones. In flotation processes, they can act as collectors, and in catalysis, they can be used as phase transfer catalysts or templates for zeolite synthesis. We present the surface quasi-two-dimensional electrolyte (STDE) model as a universal model for the description of ionic surfactants’ adsorption at fluid interfaces that explicitly considers the electric double formation upon surfactant adsorption. The model was adapted to describe phenomena occurring for adsorption of dicephalic surfactants as counterion specificity or formation of surfactant ioncounterion associates. As an example, we applied the model to explain the mechanism of adsorption at water/air interface of novel dicephalic cationic surfactants, N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dibromides and N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dimethylsulfates, both belonging to the class of chemodegradable surfactants having amide bond between two quaternary amine cationic groups and a single hydrophobic tail. Additionally, we used the same model to describe adsorption isotherms of N,N-bis[3,3- (dimethylamine)propyl]alkylamide dichlorides, having as two hydrophilic groups tertiary amines, which charge is pH-dependent. Application of the STDE model allowed an excellent description of experimental adsorption isotherm of dicephalic cationic surfactants and explained the specific features connected with the presence of multicharged headgroup.
Źródło:
Wiadomości Chemiczne; 2021, 75, 9-10; 1119--1155
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative effectiveness of biochar derived from tropical feedstocks on the adsorption for ammonium, nitrate and phosphate
Autorzy:
Zou, Ganghua
Shan, Ying
Dai, Minjie
Xin, Xiaoping
Nawaz, Muhammad
Zhao, Fengljang
Powiązania:
https://bibliotekanauki.pl/articles/2203133.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nutrients
soil amendment
adsorption model
biochars
tropical feedstock
składniki odżywcze
model adsorpcji
odżywianie gleby
biowęgle
surowce tropikalne
Opis:
Biochar has been extensively studied as a soil amendment to reduce nutrients losses. However, the comparative effectiveness of biochar adsorption capacity for ammonium (NH4 -N), nitrate (NO3 -N), and phosphate (PO4-P) remains unknown. In the present study, the effects of feedstock (banana stem and coconut shell) and temperature (300, 500, and 700°C) on biochar adsorption ability for NH4-N, NO3-N, and PO4-P were investigated and fitted by three adsorption models, viz Freundlich, Langmuir, and linear. Freundlich (R2 = 0.95–0.99) and Langmuir (R2 = 0.91–0.95) models were found suitable for adsorption of NH4 -N. The maximum adsorption capacity (Qm) for coconut shell biochar increased with pyrolysis temperature (Qm = 12.8–15.5 mg g-1) and decreased for banana stem biochar (Qm = 12.9–9.7 mg g-1). In the case of NO3 -N adsorption, Freundlich (R2 = 0.82–0.99) and linear model (R2 = 1.00) were found suitable while Langmuir model showed much less contribution, similarly adsorption of PO4-P, was not supported by these three models. The minimum concentrations required for adsorption of phosphate were recorded as 36, 8, and 3 mg L-1 using pyrolyzed biochar at the temperatures of 300, 500, and 700°C, respectively. These results indicate that the feedstock and pyrolysis temperature, as well as aquatic nutrient concentration, were important factors for the adsorption of inorganic nitrogen and phosphorus.
Źródło:
Archives of Environmental Protection; 2022, 48, 4; 25--34
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In-situ nitrate remediation using nano iron/nickel particles
Autorzy:
Tehrani, M. R. F.
Vossoughi, M.
Shamsai, A.
Powiązania:
https://bibliotekanauki.pl/articles/206934.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
nickel
porous materials
reaction kinetics
adsorption model
nitrate removal
nitrates
nikiel
materiały porowate
kinetyka reakcji
model adsorpcji
usuwanie azotanów
azotany
Opis:
Originally, the application of nano zero valent iron/nickel (nZVI/Ni) particles for nitrate removal in porous media was studied. nZVI/Ni was prepared and employed in batch and continuous modes. Based on batch experiments, the reaction kinetics was consistent with the adsorption model by the order of 1–1.5. The variation of the kinetics order depends on pH and nickel content. So that highest reactivity was observed for nZVI with 10% of Ni at pH ≤ 3. Nitrate remediation in a continuous system was mostly influenced by seepage velocity, quantity and freshness of nZVI/Ni and particle size of porous media. In a batch mode, the maximum nitrate removal was 99% while in a continuous mode it did not exceed 85%.
Źródło:
Environment Protection Engineering; 2014, 40, 3; 75-86
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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