Temat: Zn(II) - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Adsorption of Zn(II) ions from aqueous environment by surface modified Strychnos potatorum seeds, a low cost adsorbent
Autorzy:: Senthil, Kumar P.
Tematy:: adsorption
isotherms
kinetics
shrinking core model
Zn(II); Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/949520.pdf Link otwiera się w nowym oknie
Opis:: The surface modified Strychnos potatorum seeds (SMSP), an agricultural waste has been developed into an effective adsorbent for the removal of Zn(II) ions from aqueous environment. The Freundlich model provided a better fit with the experimental data than the Langmuir model as revealed by a high coefficient of determination values and low error values. The kinetics data fitted well into the pseudo-second order model with the coefficient of determination values greater than 0.99. The influence of particle diffusion and film diffusion in the adsorption process was tested by fitting the experimental data with intraparticle diffusion, Boyd kinetic and Shrinking core models. Desorption experiments were conducted to explore the feasibility of regenerating the spent adsorbent and the adsorbed Zn(II) ions from spent SMSP was desorbed using 0.3 M HCl with the efficiency of 93.58%. The results of the present study indicates that the SMSP can be successfully employed for the removal of Zn(II) ions from aqueous environment.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Adsorption of Zn2+ from solutions on manganese oxide obtained via ozone precipitation reaction
Autorzy:: Contreras-Bustos, R.
Espejel-Ayala, F.
Cercado-Quezada, B.
Jiménez-Becerril, J.
Jiménez-Reyes, M.
Tematy:: manganese dioxide
aqueous Zn(II) solutions
adsorption process; Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/778323.pdf Link otwiera się w nowym oknie
Opis:: Synthesis via ozone precipitation reaction was used to obtain manganese dioxide (OMD) and it was probed as an adsorbent for zinc ions. Adsorption was followed along shaking time and increasing ratio [NO3 –] / [Zn2+], and isotherms were obtained at different pH values and in the presence of several anions (chloride, nitrate, sulphate, and acetate). It was found that adsorption equilibrium is fast and follows the pseudo-second order model (qe = 34 ±1 mg/g and K = 0.07 ±0.01 g/mg h). Isotherms were fitted to Langmuir, Freundlich, and Langmuir-Freundlich models, and the best fitting was found with the last one. The process is dependent on pH and the efficiency increases from pH 1 to 4. The ratio [NO3 –] / [Zn2+] up to 3 does not seem to change the behaviour of the process. Regarding the anions, the efficiency of Zn(II) adsorption occurs according to: acetate > nitrate and sulphate > chloride. Manganese oxide obtained via ozonization is an excellent adsorbent for zinc ions.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Adsorption behavior of Zn(II) onto natural minerals in wastewater. A comparative study of bentonite and kaolinite
Autorzy:: Chai, W.
Huang, Y.
Su, S.
Han, G.
Liu, J.
Cao, Y.
Tematy:: adsorption
Zn(II)
wastewater
clay minerals
structural properties; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/109926.pdf Link otwiera się w nowym oknie
Opis:: In order to remove the harmful metal ions in lead-zinc mineral processing wastewater, two natural clay minerals (bentonite and kaolin) were used as adsorbents and Zn(II) ions were the emphasis in this work. The adsorption behaviors including kinetics and isotherms were investigated by batch experiments. In addition, the adsorption mechanisms were studied by means of zeta potential testing, optical microscope and XRD analysis. The results show that the adsorption process can be best described as the pseudo-second order kinetic model. The adsorption equilibrium data of bentonite and kaolinite can be respectively fitted best by Langmuir and Freundlich models. Thermodynamic studies display that the adsorption of Zn(II) onto clays is non-spontaneous and endothermic. The maximum capacity of Zn(II) adsorbed on bentonite and kaolinite respectively reaches to 79.2 mg·g-1 and 6.35 mg·g-1 at 25 °C. The structural differences of bentonite and kaolinite result in the differences in adsorption behavior and mechanism. The interaction mechanisms of Zn(II) with bentonite and kaolinite involve electrostatic attraction, cation exchange, surface complex and precipitation. Bentonite as adsorbent has the potential to remove Zn2+ better than kaolinite.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Adsorption kinetic, equilibrium and thermodynamic investigations of Zn(II) and Ni(II) ions removal by poly(azomethinethioamide) resin with pendent chlorobenzylidine ring
Autorzy:: Kumar, P. S.
Ethiraj, H.
Venkat, A.
Deepika, N.
Nivedha, S.
Vidhyadevi, T.
Ravikumar, L.
Sivanesan, S.
Tematy:: adsorption
models
Ni(II) ions
poly(azomethinethioamide)
Zn(II) ions; Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/780002.pdf Link otwiera się w nowym oknie
Opis:: This paper reports the application of poly(azomethinethioamide) (PATA) resin having the pendent chlorobenzylidine ring for the removal of heavy metal ions such as Zn(II) and Ni(II) ions from the aqueous solutions by adsorption technology. Kinetic, equilibrium and thermodynamic models for Zn(II) and Ni(II) ions adsorption were applied by considering the effect of contact time, initial metal ion concentration and temperature data, respectively. The adsorption influencing parameters for the maximum removal of metal ions were optimized. Adsorption kinetic results followed the pseudo-second order kinetic model based on the correlation coefficient (R2) values and closed approach of experimental and calculated equilibrium adsorption capacity values. The removal mechanism of metal ions by PATA was explained with the Boyd kinetic model, Weber and Morris intraparticle diffusion model and Shrinking Core Model (SCM). Adsorption equilibrium results followed the Freundlich model based on the R2 values and error functions. The maximum monolayer adsorption capacity of PATA for Zn(II) and Ni(II) ions removal were found to be 105.4 mg/g and 97.3 mg/g, respectively. Thermodynamic study showed the adsorption process was feasible, spontaneous, and exothermic in nature.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Kinetics and isotherm modelling of Zn(II) ions adsorption onto mine soils
Autorzy:: Jalayeri, H.
Salarirad, M. M.
Ziaii, M.
Tematy:: copper mine soil
Zn(II)
adsorption kinetic
adsorption isotherms; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/110575.pdf Link otwiera się w nowym oknie
Opis:: The soils consist of various components that can play a significant role in control of heavy metals in the environment. Therefore, understanding of adsorption properties of soil is essential in solving pollution problems around mine sites. The goal of this paper is to study Zn(II) ions adsorption onto copper mine soil. Soils were examined via X-ray diffraction and scanning electron microscopy. The influence of various parameters such as effect of pH, adsorbent dose, and initial concentration of Zn(II) ions on adsorption was evaluated by batch method. The adsorption isotherms of Zn(II) ions such as Langmuir, Freundlich, and Temkin were studied. The Langmuir isotherm indicated an excellent fit for the experimental data in comparison with other isotherms that shown monolayer adsorption onto a homogenous surface. A number of kinetic models were tested to fit the kinetic data. The results show that soils can be more effective in decreasing heavy metals contamination specially Zn(II) ions from solution phase.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Synteza i przebadanie właściwości spktrofotmetrycznych pochodnych fornylochromonu, fluorescencyjnych receptorów jonów metali.
Synthesis and examination of spectrophotometric properties of 3 formylchromone derivatives – fluorescent metal ions receptors.
Autorzy:: Indyka, Łukasz
Opis:: The reactions of 3-formylchromone with thiosemicarbazide, 8-aminoquinoline and alkilamine pyrrol[2,3-b]quinoxaline derivative were carried out. As the results of the first two reactions, two compounds were obtained for which the UV/VIS absorption and fluorescence spectra were measured in the presence of various metal ions. The described in the literature thiosemicarbazone derivative recognize the Zn(II) ions with the fluorescence enhancement. The product obtained in the reaction with 8-aminoquinoline binds Zn(II), Cd(II), Hg(II), Cu(II), Co(II) and Ni(II) ions, however complexes do not show a significant fluorescence. The reaction of 3-formylchromone with the alkilamine pyrrol[2,3-b]quinoxaline derivative led to the mixture of products that separation and purification failed.
Przeprowadzono reakcje 3-formylochromonu z tiosemikarbazydem, 8-aminochinoliną oraz pochodną pirolo[2,3-b]chinoksaliny. W wyniku dwóch pierwszych reakcji otrzymano dwa związki, dla których wykonano pomiary widm absorpcji w zakresie UV/VIS i fluorescencji w obecności jonów metali. Produkt reakcji z tiosemikarbazydem opisany wcześniej w literaturze kompleksuje jony Zn(II), czemu towarzyszy wzrost intensywności fluorescencji. Drugi z otrzymanych związków w reakcji z 8-aminochinoliną wiąże się z jonami Zn(II), Cd(II), Hg(II), Cu(II), Co(II) i Ni(II), jednak utworzone związki kompleksowe wykazują niewielką fluorescencję. Reakcja 3-formylochromonu z pochodną alkiloaminową pirolo[2,3-b]chinoksaliny prowadziła do uzyskania mieszaniny produktów, których rozdział i oczyszczenie się nie powiodły.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 7.

Tytuł:: Towards tuning PDT relevant photosensitizer properties : comparative study for the free and $Zn^{2+}$ coordinated meso-tetrakis[2,6-difluoro-5-(N-methylsulfamylo)phenyl]porphyrin
Autorzy:: Arnaut, Luis G.
Stochel, Grażyna
Pereira, Mariette M.
Dąbrowski, Janusz
Pucelik, Barbara
Opis:: The spectroscopic, photochemical, and biological studies of 5,10,15,20-tetrakis[2,6-difluoro-5(N-methylsulfamylo)phenyl]porphyrinate Zn(II) (ZnF2PMet) were carried out including absorption and fluorescence spectra, fluorescence quantum yields, triplet absorption spectra, triplet lifetimes, singlet oxygen quantum yield, and reactive oxygen species (ROS) detection under biological conditions and compared with its free-base analog (F2PMet). Zinc coordination into the porphyrin ring results in decrease of hydrophobicity and in higher cellular uptake. F2PMet localized specifically in endoplasmic reticulum and mitochondria while the ZnF2PMet is more diffused all over the cell, bonded to membrane proteins, as assessed by fluorescence microscopy. Zn-porphyrin exhibits greater singlet oxygen quantum yield than its free-base analog. Studies with fluorescent probes confirm that the ZnF2PMet produces mostly singlet oxygen, whereas F2PMet generates more hydroxyl radicals as the ROS. F2PMet is a more effective photosensitizer in vitro than its zinc complex, thus, the final photodynamic effect depends more on the nature of ROS than on the higher cellular uptake.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 8.

Tytuł:: Reactivity of nZVI in the removal of Cu(II) and Zn(II) from synthetic mine drainage
Autorzy:: Suponik, Tomasz
Neculita, Carmen Mihaela
Tematy:: mining industry
nZVI
zero-valent iron
Cu(II)
Zn(II)
przemysł wydobywczy; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/2032928.pdf Link otwiera się w nowym oknie
Opis:: Adsorption properties, including isotherms and kinetics, of nano zero-valent iron (nZVI) for Cu(II) and Zn(II) removal from synthetic mine drainage were evaluated in batch tests. The influence of contact time, nZVI doses, pH, ionic strength, temperature, and concentration on nZVI adsorption properties was assessed. The removal of Cu(II) and Zn(II) increased with pH from 3 to 7 and then stabilized up to pH 10. Moreover, the increased Cu(II) adsorption capacity upon increasing temperature and a positive enthalpy change (ΔH) indicate that the adsorption process is endothermic. The results also showed that the adsorption equilibrium for Cu(II) and Zn(II) was achieved after 50 and 30 min, respectively. Kinetics were best described by a pseudo-nth order model, with the order of sorption of 2.231 and 1.363, and the rate constants of 0.0008 and 0.0679 mg1-n·gn-1/min, for Cu(II) and Zn(II), respectively. The correlation between the amount of metals adsorbed on nZVI surface and the residual amount of metals in water during isothermal tests was best described by the nonlinear Sips model. Using this model, high q maxS were found: 286.6 mg/g and 142.6 mg/g, for Cu(II) and Zn(II), respectively, as indication of their high sorption capacity.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Strukturalna i spektroskopowa charakterystyka kompleksu Zn(II) opartego na wybranej pochodnej 1,3,4-tiadiazolu - badania teoretyczne
Structural and spectroscopic characterization of a Zn(II) complex based on a selected 1,3,4-thiadiazole derivative - theoretical studies
Autorzy:: Grzybowska, Joanna
Opis:: Związki oparte na 1,3,4-tiadiazolu stały się w ostatnim czasie obiektem szerokiego zainteresowania, jako że wiele z nich nadaje się do użytku medycznego i farmaceutycznego. Głównym celem przedstawionych tu badań teoretycznych było stworzenie, z wykorzystaniem obliczeń metodą teorii funkcjonałów gęstości oraz jej wariantu czasowo-zależnego, strukturalnej i spektroskopowej charakterystyki nowo-zsyntetyzowanego kompleksu Zn(II) z rezorcynową pochodną tiadiazolu, umożliwiające wyjaśnienie jego doświadczalnie obserwowanych właściwości fotofizycznych. Badania obejmowały szczegółową analizę konformacyjną z uwzględnieniem różnych sposobów koordynacji metalu do liganda, analizę oddziaływania metal/ligand oraz symulacje elektronowej absorpcji i fluorescencji. Wyniki potwierdziły, że preferowana jest kompleksacja cynku do liganda poprzez jeden z atomów azotu w tiadiazolu oraz przez deprotonowaną grupę orto-hydroksylową w rezorcynie, z zachowaniem planarnego ułożenia pierścieni rezorcyny i tiadiazolu względem siebie oraz nieznacznie preferowaną tetraedryczną geometrią w sferze koordynacyjnej Zn(II). Obliczone dla takich struktur długości fal absorpcji i emisji pokrywają się w stosunkowo satysfakcjonującym stopniu z danymi eksperymentalnymi, choć generalnie obserwowane jest przesunięcie hipsochromowe, a z analizy wzbudzeń wynika, że sygnały te pochodzą głównie od przejść elektronowych π–π* w obrębie liganda rezorcynowo-tiadiazolowego, bez udziału orbitali metalu. Obserwowane doświadczalnie pojawienie się dodatkowej niskoenergetycznej absorpcji oraz batochromowe przesunięcie sygnału emisji dla kompleksu w porównaniu z ligandem dobrze koreluje ze zmniejszeniem przerwy energetycznej HOMO/LUMO wskutek kompleksacji.
1,3,4-thiadiazole-based compounds have recently attracted a lot of attention, as many of them are suited for medicinal and pharmaceutical use. The main goal of the presented theoretical studies was to create (using density functional theory and its time-dependent variant calculations) a structural and spectroscopic characterization of the newly synthesized complex of Zn(II) with the resorcynyl-thiadiazole derivative, and thus shed a light on its experimentally observed photophysical properties. The research involved a detailed conformational analysis considering different coordination modes of the metal to the ligand, a coordination-bonding analysis, and electronic absorption and fluorescence emission simulations. The results confirmed that the complexation of Zn(II) to the resorcynyl-thiadiazole ligand occurs preferentially through one of the nitrogen atoms in the thiadiazole ring and the deprotonated ortho-hydroxyl group in the resorcynyl fragment, with the planar arrangement of the resorcynyl-thiadiazole and an only slightly more favoured tetrahedral Zn(II) coordination sphere. The absorption and emission wavelengths computed for such structures agree with the experimental data in a reasonably satisfactory manner, although an overall blue-shift was observed, and the excitations analysis showed a resorcynyl-thiadiazole-ligand-centred π–π* origin of the dominant electronic transitions with no involvement of the metal orbitals. The experimentally observed appearance of the low-energy absorption intensity and the red-shift of the emission signal for the complex compared to the ligand correlates well with a decrease in the HOMO/LUMO gap occurring upon the complexation.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Skocz do pozycji: 10.

Tytuł:: Structural, spectroscopic and microbiological characterization of a Zn(II) complex based on a 1,3,4-thiadiazole derivative : experimental and computational studies
Autorzy:: Budziak-Wieczorek, Iwona
Figiel, Małgorzata
Karcz, Dariusz
Rząd, Klaudia
Matwijczuk, Arkadiusz
Korona-Glowniak, Izabela
Srebro-Hooper, Monika
Grzybowski, Joachim
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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