Temat: adsorption model - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Recovery of cobalt ions from diluted solutions by means of protonated dry alginate beads
Autorzy:: Aracena, Alvaro
Padilla, Sebastián
Jerez, Oscar
Tematy:: recovery mechanism
cobalt ions
alginate beads
kinetic adsorption model
elution; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110037.pdf Link otwiera się w nowym oknie
Opis:: Mining effluents contain cobalt ions that can damage humans and flora. However, this meta also has high commercial value when recovered. The objective of this research work was to recover cobalt (Co²⁺) from diluted solutions using a biosorbent, specifically protonated dry alginate beads (PDAB). Experimental work was carried out in batch from an initial concentration of 22×10-6 kg dm^-3 Co²⁺ and 80 mg alginate. Variables such as agitation, pH solution, experimental time, isotherm values, and temperature were analyzed. Maximum cobalt recoveries were obtained at pH values above 5.0, reaching 60.6×10^-3 kg kg^-1 of PDAB. Cobalt recovery occurred with ion exchange mechanisms from alginate carboxyl group proton release. Experimental data had excellent fit with both the Lagergren kinetic model (pseudo-first order) and the Langmuir isotherm model. As temperature increased, cobalt recovery increased. The calculated activation energy was 12.8 kJ mol^-1. Compositional measurements obtained by scanning electron microscope and energy-dispersive X-ray spectroscopy for alginate crosssections showed uniform distributions of cobalt concentrations throughout the spherical alginate structure, independent of solution pH, contact time, or temperature. Furthermore, elution gave significant cobalt re-extraction (98.2%) and demonstrated PDAB reusability.
Dostawca treści:: Biblioteka Nauki

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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
Tematy:: kationowe surfaktanty wielofunkcyjne
surfaktanty chemodegradowalne
adsorpcja
napięcie powierzchniowe
model adsorpcji
multifunctional cationic surfactants
chemodegradable surfactants
adsorption
surface tension
adsorption model; Pokaż więcej
Wydawca:: Polskie Towarzystwo Chemiczne
Powiązania:: https://bibliotekanauki.pl/articles/2057918.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Phosphorus sorption capacity of different types of opoka
Zdolnosc wchlaniania fosforu przez rozne rodzaje opoki
Autorzy:: Cucarella, V.
Zaleski, T.
Mazurek, R.
Tematy:: calcium
Freundlich adsorption model
Freundlich isotherm
langmuir isotherm
opoka
phosphorus removal
silica
sorption
phosphorus sorption; Pokaż więcej
Wydawca:: Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Powiązania:: https://bibliotekanauki.pl/articles/81895.pdf Link otwiera się w nowym oknie
Opis:: The bedrock opoka has been lately reported as an appropriate reactive media for onsite wastewater treatment systems due to its high phosphorus (P) sorption capacity. However, variations on its chemical composition may affect its reactivity with P, therefore leading to a variable P removal effi ciency. In this paper, the P-sorption capacity of three different types of opoka from the region of Miechów, Poland, is reported. According to the silica and carbonate content, opoka samples were classifi ed as light--weight and heavy-weight opoka. When heated over 900°C, opoka showed a very high P-sorption capacity that was well correlated to its Ca content. P-sorption isotherms from batch experiments with an artifi cial P solution were plotted and fi tted to the Langmuir and Freundlich adsorption models. The Freundlich isotherm appeared to model better the P-sorption of light opoka and the Langmuir isotherm of heavy opoka, suggesting different dominating mechanisms of P-sorption by light and heavy opoka.
Według ostatnich badań opoka jest uważana za sorbent, który ze względu na wysoką zdolność wiązania fosforu, może mieć zastosowanie w przydomowych oczyszczalniach ścieków. Jednakże różnorodność składu chemicznego opoki wpływa na intensywność wiązania P i prowadzi do różnej efektywności procesu oczyszczania ścieków. W pracy przedstawiono zdolność wiązania P przez trzy rodzaje opok pobranych w rejonie Miechowa (woj. małopolskie). Na podstawie zawartości krzemionki i węglanów próbki zostały podzielone na opokę lekką i ciężką. Po wypaleniu w temperaturze ponad 900°C opoka charakteryzowała się bardzo wysoką zdolnością wiązania P, silnie skorelowaną z zawartością Ca. Krzywe sorpcji P, otrzymane podczas doświadczenia ze sztucznie sporządzonym roztworem zawierającym rozpuszczony P, porównano z modelami absorpcji opracowanymi przez Langmuira i Freundlicha. Izoterma Freundlicha była bardziej zbliżona do krzywej wiązania P przez opokę lekką, z kolei model Langmuira okazał się bliższy krzywej sorpcji opoki ciężkiej.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

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
Tematy:: nutrients
soil amendment
adsorption model
biochars
tropical feedstock
składniki odżywcze
model adsorpcji
odżywianie gleby
biowęgle
surowce tropikalne; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2203133.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

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.
Tematy:: determination
adsorption isotherm model
biosorption
chromium
cherry
leaf
Muntingia calabura; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/11799.pdf Link otwiera się w nowym oknie
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.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Synteza nowej klasy chelatujących żywic jonowymiennych do usuwania śladowych zanieczyszczeń z wody
Synthesis of a new class of chelating ion exchange resins to remove trace impurities from the water
Autorzy:: Berniak, Tomasz
Opis:: N-winyloformamid (NVF), rozpuszczalny w wodzie monomer winylowy jest prekursorem poliwinyloaminy i dużej grupy polimerów hydrofilowych z merami winyloaminowymi w tym hydrożeli i jonitów [1]. NVF łatwo polimeryzuje według mechanizmu rodnikowego. Kopolimeryzuje z większością znanych monomerów winylowych z tendencją do naprzemienności. Polimeryzację i kopolimeryzację wolnorodnikową NVF można realizować techniką blokową, rozpuszczalnikową, emulsyjną i suspensyjną. W prezentowanej pracy wykonano szereg sieciujących kopolimeryzacji NVF z diwinylobenzenem (DVB w odwróconej suspensji i techniką blokową stosując wodę, etanol i dimetyloformamid (DMF) jako „porogen”. Stosowano inicjatory azowe 2,2-azodiizobutylonitryl (AIBN), 2,2-azobis(2metylopropionoamidyny) (AIBA) oraz nadtlenek dibenzoilu (BPO). W charakterze fazy zwartej stosowano olej metylosilikonowy. Po hydrolizie alkalicznej otrzymano anionity z I-rzędowymi grupami aminowymi. Dokonano charakterystyki fizykochemicznej oznaczając strukturę, skład, porowatość, rozmiary i kształt ziaren w oparciu o pomiary DRIFT, EA TPM. Oznaczono także stopień pęcznienia i zawartość wody w żywicy metodą grawimetryczną oraz pojemność jonowymienną. Dla wybranych preparatów wykonano pomiary kinetyki adsorpcji jonów Cu2+ oraz izotermy adsorpcji.
N-winyloformamide (NVF), vinyl monomer soluble in water is the precursor of polyvinylamine and huge group of hydrophilic polymers with vinylamine structural unit including hydrogel and ion exchanger. NVF readily polymerizes according to the radical mechanism. NVF copolymerizes with variety of commercially important vinyl monomers exhibits a strong tendency to form alternating copolymers. Polymerization and free radical copolymerization of NVF can be carried out via block, solvents, emulsion and suspension techniques. In the present work, the series of cross-linking copolymerization of NVF with divinylbenzene (DVB) via inverse suspension and block technique were realized using water, ethanol, and dimethylformamide (DMF) as "porogen". 2,2′-azobis(2-methylpropionitrile) (AIBN), 2,2′-azobis(2-methylpropionamidine) dihydrochloride (AIBA) and dibenzoyl peroxide (BPO) as initiators were used. Oil methylsilicone was used as a continuous phase. Alkaline hydrolysis gives anion-exchanger with I-row amino groups. Physicochemical characterization was performed by determining the structure, chemical composition, porosity, particle size and shape based on measurement DRIFT EA TPM. The level of swelling ratio, and water content in the resin were determined by gravimetric method and the ion exchange capacity. For certain samples adsorption kinetics of Cu 2+ ions and the adsorption isotherm were performed.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Tytuł:: In-situ nitrate remediation using nano iron/nickel particles
Autorzy:: Tehrani, M. R. F.
Vossoughi, M.
Shamsai, A.
Tematy:: nickel
porous materials
reaction kinetics
adsorption model
nitrate removal
nitrates
nikiel
materiały porowate
kinetyka reakcji
model adsorpcji
usuwanie azotanów
azotany; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/206934.pdf Link otwiera się w nowym oknie
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%.
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Physicochemical research gemini pseudopeptides in biological system
Fizykochemiczne badania pseudopeptydów bliźniaczych w układach biologicznych
Autorzy:: Szafraniec, Julita
Opis:: Celem przeprowadzonego, fizykochemicznego badania było scharakteryzowanie oddziaływań pomiędzy amfifilowym pseudopeptydem bliźniaczym (gemini amphiphilie pseudopeptide, GAP), a głównym fosfolipidem surfaktantu płucnego, czyli dwupalmitynofosfatydylocholiną (DPPC). Do wykonania tego doświadczenia zastosowano powierzchniową wagę Langmuira, dzięki której otrzymano izotermy ciśnienia (П/A) oraz potencjału powierzchniowego (∆V/A) dla jednoskładnikowych monowarstw GAP i DPPC oraz monowarstw mieszanych o stosunku molowym GAP do DPPC: 1:9, 3:7, 1:1, 7:3 i 9:1. Na podstawie izoterm ściskania wyznaczono charakterystyczne parametry powierzchniowe badanych monowarstw, których analiza pozwoliła określić mieszalność pomiędzy cząsteczkami GAP a DPPC w warstwie powierzchniowej. Stwierdzono również, że monowarstwa DPPC oraz mieszana monowarstwa o ułamku molowym GAP równym 0,1 występuje w stanie ciekłym skondensowanym, a pozostałe filmy powierzchniowe w stanie ciekłym rozprężonym. Wywnioskowano, że wzrost zawartości GAP w monowarstwie zmniejsza jej kondensację. W badanych filmach powierzchniowych przeważają siły międzycząsteczkowe odpychające, które powodują ich destabilizację. W niniejszej pracy dowiedziono, że wzrost zawartości GAP w monowarstwie powoduje zmniejszanie stabilności termodynamicznej układów.
The goal of following physicochemical research was to characterize intermolecular forces between gemini amphiphilie pseudopeptide -GAP and main phospholipid pulmonic surfactant - Dipalmitoylphosphatidylcholine (DPPC). To achieve this experiment Langmuir–Blodgett trough was used which resulted in obtaining the pressure isotherms (П/A) and surface potential isotherms (∆V/A) for single-component in monolayers GAP i DPPC and composed monolayers where the mol ratios of GAP to DPPC are: 1:9, 3:7, 1:1, 7:3 i 9:1. Based on the pressure isotherms the characteristic surface parameters of tested monolayers were allotted. Analysis of those layers let to define the miscibility between GAP particles in surface layer. It was concluded that DPPC monolayer and composed monolayer with GAP mol fraction equal to 0,1, occurs in condensed liquid state. However, rest of the surface films occurs in expanded liquid state. The conclusion was that with the growth of GAP content in monolayer, the condensation decreases. In tested surface films the forces of repulsion dominate and cause their destabilization. The following research proved that the growth of GAP in monolayer causes decrease of thermodynamic stability of the arrangements.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Tytuł:: Decolorization of Cationic Dye from Aqueous Solution by Multiwalled Carbon Nanotubes
Autorzy:: Ahmed, Salwa H.
Rasheed, Ekehwanh A.
Rasheed, Luma A.
Abdulrahim, Firas R.
Tematy:: multiwalled carbon nanotubes
methylene blue
adsorption
adsorption equilibrium
kinetics model; Pokaż więcej
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Powiązania:: https://bibliotekanauki.pl/articles/59114217.pdf Link otwiera się w nowym oknie
Opis:: Methylene blue is a synthetic and cationic dye that finds utility in different fields including pharmaceutical, paper, textile, printing, carpet, and photography industries. Adsorption is a very effective technique to decolorize contaminated wastewater. This study aimed to determine the efficacy of Multiwalled Carbon Nanotubes (MWCNTs) as an adsorbent for decolorization of MB dye from aqueous solutions. The study examined various characteristics affecting adsorption, including concentration of dye, pH value, dosage of MWCNTs, and contact time. The results that growing the adsorbent dosage from (25 to 120) mg increased the dye efficiency rate from 62% to 98%, respectively, were shown. The study also evaluated pH, which is among the most critical factors influencing removal efficiency. The best pH for the removal efficiency was 6 at an initial concentration of MB dye 20 mgL-1, a contact time 60 min, and an MWCNT dosage 100 mg. Langmuir, Freundlich, and Temkin isotherms were used to describe the adsorption equilibrium. The Langmuir isotherm with an R2 value of 0.9968 and a maximum capacity for adsorption of 19.6 mgg-1 provided a suitable fit for the data of the experiment. In comparison between the suitability of kinetic models pseudo-first-order, pseudo-second order, and Weber–Morris, the kinetics model’s correlation value was shown to be greater than that of the pseudo-second order kinetic model with an R2 value of 0.9982.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: The Ability of Peat in Adsorption of Biogenic Elements from Water Environment
Autorzy:: Matsuska, Oksana
Suchorska, Olga
Gumnitsky, Jaroslaw
Tematy:: wastewater
ammonium nitrogen
phosphates
adsorption
peat
adsorption isotherms
coefficient of determination
Langmuir model
Freundlich model; Pokaż więcej
Wydawca:: Polskie Towarzystwo Inżynierii Ekologicznej
Powiązania:: https://bibliotekanauki.pl/articles/124877.pdf Link otwiera się w nowym oknie
Opis:: The possibilities of using a natural sorbent – peat for the wastewater treatment of ammonium ions and phosphates discharged from runoff into natural reservoirs at high concentrations were investigated. The peat of from the Vereshchytsya-Yanovske deposit of Ukraine of two depths: lowland and upland, was studied. It was established that the lowland samples of peat have higher sorption properties to the investigated pollutants from the aquatic environment than the upland ones. A greater moisture loss in the lowland peat species was observed, as well as the major part of the plant fibers in its structure, which explains its sorption properties. Due to the high content of humic substances, the extraction of cations from the water by peat can occur due to the ion exchange. The adsorption isotherms of both ammonium and phosphate ions on the top and lowland peat species of the Vereshchytsya-Yanovske deposit were constructed and presented. The adsorption isotherm obtained in the experimental studies was used to mathematically establish the isotherm equation, using the Langmuir and Freundlich models to describe the equilibrium of the sorption processes under study. The degree of appropriation of linear equations to the experimental data was evaluated on the basis of the deterministic coefficient, which enabled to determine that in each case the Langmuir equations describe the adsorption isotherms more adequately.
Dostawca treści:: Biblioteka Nauki

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