Equilibrium Sorptions in Heterogeneous Ion Exchange Membranes

1992 ◽  
Vol 57 (9) ◽  
pp. 1905-1914
Author(s):  
Miroslav Bleha ◽  
Věra Šumberová
Keyword(s):  
Experimental Data ◽  
Ion Exchange ◽  
Total Content ◽  
Distribution Coefficients ◽  
Exchange Capacity ◽  
Ion Exchange Membranes ◽  
Ion Exchange Capacity ◽  
Equilibrium Sorption ◽  
Inhomogeneity Factor

The equilibrium sorption of uni-univalent electrolytes (NaCl, KCl) in heterogeneous cation exchange membranes with various contents of the ion exchange component and in ion exchange membranes Ralex was investigated. Using experimental data which express the concentration dependence of equilibrium sorption, validity of the Donnan relation for the systems under investigation was tested and values of the Glueckauf inhomogeneity factor for Ralex membranes were determined. Determination of the equilibrium sorption allows the effect of the total content of internal water and of the ion-exchange capacity on the distribution coefficients of the electrolyte to be determined.

Determination of the ion-exchange capacity of anion-selective membranes

2014 ◽  
Vol 39 (10) ◽  
pp. 5054-5062 ◽  
Author(s):  
F. Karas ◽  
J. Hnát ◽  
M. Paidar ◽  
J. Schauer ◽  
K. Bouzek
Keyword(s):  
Ion Exchange ◽  
Exchange Capacity ◽  
Ion Exchange Capacity ◽  
Selective Membranes

Preparation of Highly Stable Ion Exchange Membranes by Radiation-Induced Graft Copolymerization of Styrene and Bis(vinyl phenyl)ethane Into Crosslinked Polytetrafluoroethylene Films

2006 ◽  
Vol 4 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Tetsuya Yamaki ◽  
Junichi Tsukada ◽  
Masaharu Asano ◽  
Ryoichi Katakai ◽  
Masaru Yoshida
Keyword(s):  
Ion Exchange ◽  
Proton Conductivity ◽  
Water Uptake ◽  
Graft Copolymerization ◽  
Exchange Capacity ◽  
Polymer Electrolyte Fuel Cells ◽  
Ion Exchange Membranes ◽  
Aromatic Rings ◽  
Ion Exchange Capacity ◽  
Radiation Induced

We prepared novel ion exchange membranes for possible use in polymer electrolyte fuel cells (PEFCs) by the radiation-induced graft copolymerization of styrene and new crosslinker bis(vinyl phenyl)ethane (BVPE) into crosslinked polytetrafluoroethylene (cPTFE) films and subsequent sulfonation and then investigated their water uptake, proton conductivity, and stability in an oxidizing environment. In contrast to the conventional crosslinker, divinylbenzene (DVB), the degree of grafting of styrene∕BVPE increased in spite of high crosslinker concentrations in the reacting solution (up to 70mol%). Quantitative sulfonation of the aromatic rings in the crosslinked graft chains resulted in the preparation of membranes with a high ion exchange capacity that reached 2.9meq∕g. The bulk properties of the membranes were found to exceed those of Nafion membranes except for chemical stability. The emphasis was on the fact that the BVPE-crosslinked membranes exhibited the higher stability in the H2O2 solution at 60°C compared to the noncrosslinked and DVB-crosslinked ones, as well as decreased water uptake and reasonable proton conductivity. These results are rationalized by considering the reactivity between styrene and the crosslinker, which is an important factor determining the distribution of the crosslinks in the graft component. In the case of BVPE, the crosslinks at a high density were homogeneously incorporated even into the interior of the membrane because of its compatibility with styrene while the far too reactive DVB led to a crosslink formation only near the surface. The combination of both the cPTFE main chain and BVPE-based grafts, i.e., a perfect “double” crosslinking structure, is likely to effectively improve the membrane performances for PEFC applications.

An experimental study of sorption properties of natural zeolite-containing rocks and their ability for purification of aquatic solutions contaminated with Ni and Zn

2020 ◽  
Author(s):  
Liudmila Kolmykova ◽  
Valentina Nikashina ◽  
Elena Korobova
Keyword(s):  
Ion Exchange ◽  
Natural Zeolite ◽  
Natural Waters ◽  
Distribution Coefficients ◽  
Exchange Capacity ◽  
Ammonium Ion ◽  
Geochemical Barrier ◽  
Solid Domestic Waste ◽  
Ion Exchange Capacity ◽  
Model Solutions

<p>Sorption parameters of natural zeolite-containing tripolite from the Khotynetsky deposit (Russia, Oryol region) were studied in a series of experiments to evaluate possibility of its usage as a geochemical barrier for teсhnogenic Ni<sup>2+</sup> and Zn<sup>2+</sup> contaminating soils and ground waters. <br>Firstly, the tripolite total ion-exchange capacity was established by its saturation with ammonium ion and evaluating its content in the initial and ammonium forms with the help of X-ray fluorescence method. Secondly, the kinetic characteristics, namely the time necessary to reach the equilibrium state of the rock-water system containing Ni<sup>2+</sup> and Zn<sup>2+</sup> ions were determined in batch experiments using the method of "limited volume". The latter experiment was conducted using 0.5 g tripolite with 250 ml model solutions simulating natural river water (0.003 н CaCl<sub>2</sub>) and filtration water from solid domestic waste landfill (0.06 н CaCl<sub>2</sub>) and containing  2 mg/l Ni<sup>2+</sup> and  Zn<sup>2+</sup>. The time of contact between the sorbent and the model solution varied from 2 hours to 21 days. Thirdly, basing on reference data on the real content of heavy metals in the filtrates of various landfills, an experiment on determination of the tripolite equilibrium exchange (and adsorption) capacity was carried out. The prepared model solutions in the latter experiment contained 2, 5, 7 and 10 mg/l of Ni<sup>2+</sup> and Zn<sup>2+</sup>. The amount of Ni<sup>2+</sup> and Zn<sup>2+  </sup>in solutions was determined by the ICP-AES.<br>According to the obtained results, the total ion-exchange capacity of the natural tripolite equaled to 1.18 mg-eq/g. The sorption isotherms based on kinetic experiments showed that equilibrium in the studied rock-solution system took place after 200 to 500 hours of interaction. Despite natural scattering of experimental points in the range of the used Ni<sup>2+</sup> and Zn<sup>2+</sup> concentrations in the third experiment which lasted 21 days, the sorption of the studied ions by the natural tripolite can be approximated by a linear isotherm, zinc being sorbed much better than nickel. The average values of distribution coefficients (Kd) obtained for 0.003 n CaCl<sub>2</sub> aquatic solution equaled to 2.7*103 ml/g for Ni<sup>2+</sup> and 6.7*103 ml/g for Zn<sup>2+</sup>.<br>Therefore, natural tripolite of the Khotinetsky deposit may well be used as a natural geochemical barrier for extraction of technogenic Ni<sup>2+</sup> and Zn<sup>2+</sup> from natural waters draining landfills and contaminated by these ions.</p><p> </p>

DETERMINATION OF CHROMIUM(VI) IN WATER BY PIXE ANALYSIS USING ION EXCHANGE PAPER — LIMIT OF DETECTION AND INTERFERENCE BY COEXISTING ANIONS

2009 ◽  
Vol 19 (01n02) ◽  
pp. 1-8 ◽  
Author(s):  
SUREERAT THOMYASIRIGUL ◽  
HITOSHI FUKUDA ◽  
JUN HASEGAWA ◽  
YOSHIYUKI OGURI
Keyword(s):  
Ion Exchange ◽  
Proton Energy ◽  
Limit Of Detection ◽  
Deae Cellulose ◽  
Exchange Capacity ◽  
Ion Exchange Capacity ◽  
Pixe Analysis ◽  
X Ray ◽  
Chromium Vi

Concerning the PIXE analysis of Cr ( VI ) in water using ion-exchange filters, the limit of detection (LOD) and the influence of matrix anions were investigated. In order to look for the experimental condition for obtaining the minimum LOD, we measured the Cr - K α X-ray counts and background counts under the K α X-ray peak as a function of the incident proton energy and the thickness of the Mylar absorber foil in front of the detector. To investigate the interference by coexisting anions, each of PO 43-, SO 42-, NO 3-, Cl -, and F - ions and Cr ( VI ) ions were mixed in aqueous solutions and adsorbed on DE81-DEAE cellulose paper, a weakly basic anion exchanger with diethylaminoethyl functional groups. Then the filter samples were measured by PIXE using 2.5 MeV proton beams. We obtained a LOD of 0.16 µg or 8 ppb for 20 mL samples at a proton energy of 2.5 MeV and a Mylar film thickness of 50 or 100 µm. The experimental results on the mixed solutions indicated that NO 3-, Cl -, and F - as coexisting ions didn't interfere significantly with determination of a 50 µ g / L Cr ( VI ) concentration for 40 mL total solution volume, despite the total amount of anions was about 90% of ion exchange capacity of a filter. On the other hand, slight interferences by PO 43- ions were observed. However, under the same condition, we found that if the total amount of SO 42- ions was higher than 20% of ion exchange capacity, they induced significant interferences in determining Cr ( VI ).

scholarly journals UPTAKE ABILITY OF ZEOLITIC ROCK FROM SOUTH XEROVOUNI, AVDELLA, EVROS, HELLAS

2017 ◽  
Vol 43 (5) ◽  
pp. 2762
Author(s):  
E. Tzamos ◽  
A. Filippidis ◽  
N. Kantiranis ◽  
C. Sikalidis ◽  
A. Tsirambidis ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Clay Minerals ◽  
Total Content ◽  
Exchange Capacity ◽  
Small Extent ◽  
Ion Exchange Capacity ◽  
Rock Samples ◽  
Wide Range ◽  
Type Zeolite ◽  
Positive Correlations

Zeolitic rock samples from South Xerovouni contain on average, 57 wt.% HEU type zeolite, 6 wt.% clay minerals, 3 wt.% mica (total of 66 wt.% microporous minerals), 19 wt.% feldspars, 10 wt.% cristobalite and 5 wt.% quartz (total of 34 wt.% non-microporous minerals). Chemically the zeolitic rock consists mainly of 69.9 wt.% SiO2, 13.2 wt.% Al2O3, 1.2 wt.% Fe2O3t, 1.0 wt.% MgO, 3.0 wt.% CaO, 1.5 wt.% Na2O and 2.2 wt.% K2O. The zeolitic rock shows an average ammonia ion exchange capacity of 150 meq/100g. HEU-type zeolite accounts for the most of the uptake ability, while clay minerals and mica contribute to a relative small extent only. The uptake ability of the five zeolitic rock samples showed positive correlations with the content of HEU-type zeolite as well as with the total content of microporous minerals (zeolite + mica + clay minerals). Such materials could be used in a wide range and scale of agricultural, aquacultural, and environmental applications.

scholarly journals Modelling and simulation of the ion exchange process for Zn2+(aq) removal using zeolite NaY

2021 ◽  
Vol 10 (12) ◽  
pp. e310101220362
Author(s):  
Andrezza de Araújo Silva Gallindo ◽  
Reinaldo Alves da Silva Junior ◽  
Meiry Gláucia Freire Rodrigues ◽  
Wagner Brandão Ramos
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Ion Exchange ◽  
Kinetic Modelling ◽  
Fixed Bed ◽  
Exchange Capacity ◽  
Ion Exchange Capacity ◽  
Saturation Time ◽  
Capital Costs ◽  
Film Mass Transfer

The treatment of water contaminated by toxic metals using ion exchange with zeolites is becoming attractive due to its low capital costs and high potential for removal capacity. Mathematical modelling of this process allows for operational control and estimation of the ability to remove these metals. In this work, the kinetic modelling was performed based on finite bath experimental data, with Intraparticle Diffusion (IPD) and External Liquid Film Mass Transfer (MTEF) models. The models Thomas (TH), Yoon-Nelson (YN) and Solid Film Mass Transfer (MTSF) were used to estimate the saturation time, ion exchange capacity and sizing variables of a fixed bed column. For the finite bath system, the results showed that the mass transfer was better represented by the IPD phenomenon. The breakthrough curve obtained by the Aspen Adsorption (MTSF) model presented the best fit, compared with experimental data, with R2≥0.9923. The average ion exchange capacities calculated for MTSF, TH and YN were respectively 2.22, 2.12 and 2.07 meq Zn2+(aq)/ g of zeolite. The model simulated with Aspen Adsorption was also used to analyze the continuous system behaviour, by varying the height of the bed. It was observed that increasing the height, the saturation time and ion exchange capacity also increase, while reducing the height makes axial dispersion the predominant mass transfer phenomenon, which reduces the diffusion of Zn2+(aq) ions.

scholarly journals Electrical Conductivity and Ion Exchange Properties of Polyaniline Antimony Tin Tung state Nano composite

2021 ◽  
Vol 37 (2) ◽  
pp. 388-396
Author(s):  
Preethab B
Keyword(s):  
Ion Exchange ◽  
Metal Ions ◽  
Xrd Analysis ◽  
Distribution Coefficients ◽  
Exchange Capacity ◽  
Polluted Water ◽  
Ion Exchange Capacity ◽  
Nano Composite ◽  
Exchange Character ◽  
Differential Selectivity

The nano composite, polyaniline antimony tin tungstate in the H+ form was synthesized by a simple general method. EDS and ICP- AES methods were used to find the chemical constitution of the material. Further characterizations were done by TGA, XRD analysis, FTIR Spectroscopic analysis, UV-Visible DRS studies to find the optical properties, SEM for finding surface morphology, etc. Size determination using XRD peaks and TEM images confirmed its nano size. Investigation on ion exchange capacity and distribution coefficients for many metal ions revealed the ion exchange character. The composite exhibited differential selectivity forheavy metal ions such as PbII, ThIV, HgIV, etc. which are important in environmental applications like separation and treatment of polluted water from these metal ions. The electrical properties studied by Four–probe method revealed a high conductivity of 0.42 S/cm at room temperature and it decreases with an increase in temperature. These results suggest various applications of this nano compositein optoelectronics.

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