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1

Study of 2–thiocytosine/ surfactant adsorption at the R-AgLAFe/chlorate(VII) interface – impact of surfactant ionic character

Martyna Marlena, Grochowski Mariusz, Urban Teresa, Nosal-Wiercińska Agnieszka

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 2

art. no. 144322

EN

Effect of 2 – thiocytosine on the parameters of double R-AgLAFe/ chlorate(VII) interface layer in the presence of different surfactants has been studied. There were determined the adsorption parameters such as: differential capacity of the double layer (Cd) at the R-AgLAFe/ basic electrolyte interface; potential of zero charge (Ez) and surface tension at the potential of zero charge (γz). The predominance of 2–thiocytosine in formation of adsorption equilibria of 2–thiocytosine–SDS and 2– thiocytosine–CTAB mixtures as well as the competitive adsorption between molecules 2–thiocytosine-surfactant or mixed micelles was proved. The changes pointing out to different arrangement of SDS or CTAB molecules on the electrode surface also in the presence of 2–thiocytosine were observed.

2

Preparation and characterization of calcite for tannic acid adsorption: Optimization by response surface methodology coupled by Box-Cox transformation procedure

Tangarfa Mariam, Semlali Aouragh Hassani Naoul, Alaoui Abdallah

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 3

36--45

EN

Calcite depression is the most effective physicochemical process to valorize fluorine mineral. This process is achieved by adsorption of tannic acid, as the commonly used reagent, onto calcite. Adsorption investigation is very important in mineral processing. The present work focuses on optimization of physicochemical parameters of tannic acid adsorption onto calcite. Experimental study is carried out by a response surface methodology based on Box-Behnken design. Obtained results are exploited to develop a statistical model. Analysis of variance and residuals are performed to check the significance of tested models. Among these models, Cox-Box model predicts very well the obtained experimental data. This model shows that initial tannic acid concentration and solution pH as well as their interactions are the most significant parameters. Optimal conditions are achieved using the obtained statistical model. The present investigation is an important preliminary step to better understand calcite flotation behavior using tannic acid as a depressant.

3

Effect of azathioprine on the parameters of double Hg/chlorate(VII) interface layer in the presence of nonionic surfactants

Kaliszczak Waldemar, Grochowski Mariusz, Nosal-Wiercińska Agnieszka, Brycht Mariola, Checinska-Majak Dorota, Gołębiowska Beata

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1350--1356

EN

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.

4

Adsorption capacity of chosen sandy ground with respect to contaminants relocating with groundwater

Aniszewski A.

Archives of Environmental Protection

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2017

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Vol. 43, no. 1

27--33

EN

One of the most important problems concerning contaminant transport in the ground is the problem related to the definition of parameters characterizing the adsorption capacity of ground for the chosen contaminants relocating with groundwater. In this paper, for chloride and sulfate indicators relocating in sandy ground, the numerical values of retardation factors (Ra) (treated as average values) and pore groundwater velocities with adsorption (ux/Ra) (in micro-pore ground spaces) are taken into consideration. Based on 2D transport equation the maximal dimensionless concentration values (C*max c) in the chosen ground cross-sections were calculated. All the presented numerical calculations are related to the unpublished measurement series which was marked in this paper as: October 1982. For this measurement series the calculated concentration values are compared to the measured concentration ones (C*max m) given recently to the author of this paper. In final part of this paper the parameters characterizing adsorption capacity (Ra, ux/Ra) are also compared to the same parameters calculated for the two earlier measurement series. Such comparison also allowed for the estimation of a gradual in time depletion of adsorption capacity for the chosen sandy ground.

PL

Jednym z najważniejszych problemów dotyczących przepływu zanieczyszczeń w wodzie gruntowej jest problem związany z określeniem parametrów charakteryzujących zdolność adsorpcyjną gruntu dla wybranych zanieczyszczeń przemieszczających się z wodą gruntową. W tym artykule, dla chlorowych i siarczanowych wskaźników przemieszczających się w piaszczystym gruncie, wzięto pod uwagę liczbowe wartości współczynników retardacji (Ra) (traktowanych jako wartości średnie) oraz porowych prędkości wody gruntowej z adsorpcją (ux/Ra ) (w przestrzeniach makro-porowych gruntu). W oparciu o 2D równanie transportu obliczono maksymalne bezwymiarowe wartości stężeń (C*max c) w wybranych przekrojach gruntowych. Wszystkie prezentowane obliczenia numeryczne odniesiono do niepublikowanej serii pomiarowej oznaczonej w pracy jako: Październik 1982. Dla tej serii pomiarowej obliczone numerycznie wartości stężeń porównano z pomierzonymi wartościami stężeń (C*max m), które udostępniono ostatnio autorowi pracy. W końcowej części pracy parametry charakteryzujące zdolność adsorpcyjną (Ra, ux/Ra) porównano również z takimi samymi parametrami obliczonymi dla dwóch wcześniejszych serii pomiarowych. Takie porównanie pozwoliło również oszacować stopniowe w czasie wyczerpywanie się zdolności adsorpcyjnej dla wybranego gruntu piaszczystego.

5

Próba znalezienia bezpośredniej zależności pomiędzy danymi retencji i parametrami adsorpcyjnymi węgli aktywnych

Grajek H., Choma J.

Inżynieria i Ochrona Środowiska

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2006

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T. 9, nr 3

261-272

PL

Zbadano wpływ ilości dozowanego propanu na wielkość przesunięcia maksimów pików chromatograficznych i ich środków ciężkości dla przypadku idealnej nieliniowej chromatografii w odwróconej chromatografii gazowej. Wyznaczono właściwe objętości retencji propanu Vg(273), izotermy adsorpcji propanu oraz pierwsze (da/dp)T i drugie (d²a/dp²)T pochodne wielkości adsorpcji względem ciśnienia równowagowego propanu dla różnych jego ilości dozowanych do kolumny chromatograficznej. Na podstawie zmierzonych danych eksperymentalnych zaproponowano zależności pomiędzy właściwą objętością retencji (obliczoną dla maksimum piku i jego środka ciężkości) a molową różniczkową pracą adsorpcji A, i pierwszą pochodną objętości porów wypełnianych propanem względem molowej różniczkowej pracy adsorpcji w przedziale temperatur 303 ÷ 318 K.

EN

The obtained chromatographic peaks of propane were asymmetric in shape, i.e. non-Gaussian, with a sharp front and diffuse rear boundary. The retention times of their maxima and centres of gravity depended on the size of propane injected and on superposition of the diffuse rear boundaries of the peaks. Therefore shifts of the chromatographic peak maxima and centres of gravity recorded for different amount of propane injected onto chromatographic column for the case of ideal, non-linear chromatography have been investigated. The specific retention volumes corrected to the standard temperature (273.15 K), Vg(273), propane adsorption isotherms, the first (da/dp)T and the second (d²a/dp²)T derivatives have been determined on active carbons for different amounts of the injected propane on column. In the work discussed in this paper, attempts were made to find a direct relationship between specific retention volumes and data characterizing the adsorption properties of different samples of active carbon, namely the parameters of the Dubinin-Radushkevich equation. The dependencies between the specific retention volume, and the molar differential work of adsorption, A, have been calculated on the basis of the propane isotherms and using the retention times of the peaks maxima and the centres of gravity of the peaks. The obtained equations: ln Vg(273)=f1(A) and (dW/dA)T,Fc = f2(ln Vg(273)) have been used to explain the dependency between the chromatographic peak profile and the distribution function of pore volumes filled with propane with respect to the molar differential work of adsorption at different column temperatures (303 ÷ 318 K). These results confirm the interdependence of the retention time corresponding to the maxima of the propane peaks, the profile of the chromatographic peak, and the extremity of the distribution function of pore volume with respect to molar differential work of adsorption.