Improvement of Ion-Exchange Capacity of Indonesian Natural Zeolite by Sequential Washing Using Hydrofluoric Acid and EDTA Solutions

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 te&#1089;hnogenic Ni2+ and Zn2+ contaminating soils and ground waters.&#160; 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 Ni2+ and Zn2+ 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 &#1085; CaCl2) and filtration water from solid domestic waste landfill (0.06 &#1085; CaCl2) and containing &#160;2 mg/l Ni2+ and &#160;Zn2+. 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 Ni2+ and Zn2+. The amount of Ni2+ and Zn2+&#160; in solutions was determined by the ICP-AES. 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 Ni2+ and Zn2+ 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 CaCl2 aquatic solution equaled to 2.7*103 ml/g for Ni2+ and 6.7*103 ml/g for Zn2+. Therefore, natural tripolite of the Khotinetsky deposit may well be used as a natural geochemical barrier for extraction of technogenic Ni2+ and Zn2+ from natural waters draining landfills and contaminated by these ions.&#160;

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Equilibrium Sorptions in Heterogeneous Ion Exchange Membranes

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19921905 ◽

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.

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Synthesis of ionic polybenzimidazoles with broad ion exchange capacity range for anion exchange membrane fuel cell application

Journal of Polymer Science ◽

10.1002/pol.20210409 ◽

2021 ◽

Author(s):

Zelalem Gudeta Abdi ◽

Jyh‐Chien Chen ◽

Tse‐Han Chiu ◽

Hsiharng Yang ◽

Hsuan‐Hung Yu

Keyword(s):

Fuel Cell ◽

Ion Exchange ◽

Anion Exchange ◽

Exchange Capacity ◽

Anion Exchange Membrane ◽

Ion Exchange Capacity ◽

Fuel Cell Application ◽

Exchange Membrane

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Variation of Ion-Exchange Capacity, ζ Potential, and Ion-Transport Selectivities with the Number of Layers in a Multilayer Polyelectrolyte Film

Langmuir ◽

10.1021/la900391q ◽

2009 ◽

Vol 25 (13) ◽

pp. 7478-7485 ◽

Cited By ~ 54

Author(s):

Maneesha Adusumilli ◽

Merlin L. Bruening

Keyword(s):

Ion Exchange ◽

Ion Transport ◽

Exchange Capacity ◽

Ion Exchange Capacity ◽

Ζ Potential ◽

Number Of Layers ◽

Polyelectrolyte Film

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Quantitative Determination Of Carboxyl Groups In Cellulose Polymers Utilizing Their Ion Exchange Capacity And Using A Complexometric Titration

Materials Research Innovations ◽

10.1080/14328917.2004.11784850 ◽

2004 ◽

Vol 8 (3) ◽

pp. 145-146 ◽

Cited By ~ 9

Author(s):

Lidija Fras ◽

Karin Stana-Kleinschek ◽

Volker Ribitsch ◽

Majda Sfiligoj-Smole ◽

Tatjana Kreze

Keyword(s):

Ion Exchange ◽

Quantitative Determination ◽

Exchange Capacity ◽

Carboxyl Groups ◽

Ion Exchange Capacity ◽

Complexometric Titration

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The Synthesis and Ion-Exchange Property of Inorganic Material Mg1.5Mn0.5Ti0.75O4

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.511.105 ◽

2012 ◽

Vol 511 ◽

pp. 105-108

Author(s):

Jin He Jiang

Keyword(s):

Ion Exchange ◽

Inorganic Material ◽

Exchange Capacity ◽

Exchange Property ◽

Insertion Reaction ◽

Ion Exchange Capacity ◽

X Ray ◽

Thermal Crystallization ◽

Crystallization Method ◽

Saturation Capacity

Mg1.5Mn0.5Ti0.75O4 was prepared by a coprecipitation/thermal crystallization method. The extraction/insertion reaction with this material was investigation by X-ray, saturation capacity of exchange, and Kd measurement. The acid treatments of Mg1.5Mn0.5Ti0.75O4 caused Mg2+ extractions of more than 72%, while the dissolutions of Mn4+ and Ti4+ were less than 8.2%. The results showed that the Li+ extraction/insertion be progressed mainly by an ion-exchange mechanism. The acid treated samples had an ion exchange capacity of 10.6mmol/g for Li+.

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Polymer Electrolyte Membranes Based on Nafion and a Superacidic Inorganic Additive for Fuel Cell Applications

Polymers ◽

10.3390/polym11050914 ◽

2019 ◽

Vol 11 (5) ◽

pp. 914 ◽

Cited By ~ 9

Author(s):

Lucia Mazzapioda ◽

Stefania Panero ◽

Maria Assunta Navarra

Keyword(s):

Fuel Cell ◽

Ion Exchange ◽

Proton Exchange Membrane ◽

Sol Gel ◽

Composite Membranes ◽

Exchange Capacity ◽

Proton Exchange ◽

Thermal Transitions ◽

Ion Exchange Capacity ◽

Electrolyte Membranes

Nafion composite membranes, containing different amounts of mesoporous sulfated titanium oxide (TiO2-SO4) were prepared by solvent-casting and tested in proton exchange membrane fuel cells (PEMFCs), operating at very low humidification levels. The TiO2-SO4 additive was originally synthesized by a sol-gel method and characterized through x-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and ion exchange capacity (IEC). Peculiar properties of the composite membranes, such as the thermal transitions and ion exchange capacity, were investigated and here discussed. When used as an electrolyte in the fuel cell, the composite membrane guaranteed an improvement with respect to bare Nafion systems at 30% relative humidity and 110 °C, exhibiting higher power and current densities.

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Clinoptilolite: a possible support material for nitrifying biofilms for effective control of ammonium effluent quality?

Water Science & Technology ◽

10.2166/wst.2005.0391 ◽

2005 ◽

Vol 51 (11) ◽

pp. 63-70 ◽

Cited By ~ 8

Author(s):

H. Inan ◽

B. Beler Baykal

Keyword(s):

Ion Exchange ◽

High Capacity ◽

Exchange Capacity ◽

Quality Data ◽

Ammonium Ion ◽

Effective Control ◽

Support Material ◽

Ion Exchange Capacity ◽

Effluent Quality ◽

Peak Loads

Ammonium selective natural zeolite clinoptilolite is suggested as a possible support material for nitrifying biofilms to help improve effluent ammonium quality through its high capacity of ammonium removal in the process of ion exchange. This will especially be helpful in cases where the biofilter receives peak or variable loads routinely or occasionally. At the time of peak loads or shocks of ammonium, ion exchange capacity will provide a buffer for the effluent ammonium quality. Data to support this suggestion is presented.

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Adsorption and ion exchange of some groundwater anion contaminants in an amine modified coconut coir

Water Science & Technology ◽

10.2166/wst.1997.0264 ◽

1997 ◽

Vol 35 (7) ◽

pp. 89-95 ◽

Cited By ~ 21

Author(s):

Aloysius U. Baes ◽

Tetsuji Okuda ◽

Wataru Nishijima ◽

Eiji Shoto ◽

Mitsumasa Okada

Keyword(s):

Ion Exchange ◽

Low Cost ◽

Exchange Capacity ◽

Batch Adsorption ◽

Ion Exchange Capacity ◽

Strong Base ◽

Chromium Vi ◽

Freundlich Equation ◽

Adsorption Data ◽

Coconut Coir

The adsorption of nitrate, chromium (VI), arsenic (V) and selenium (VI) anions in an amine modified coconut coir (MCC-AE : with secondary and tertiary amine functionality) were studied to determine the capability of this easily prepared and low-cost material in removing typical groundwater anion contaminants. Batch adsorption-ion exchange experiments were conducted using 200 mg MCC-AE, initially containing chloride as the resident anion, and 50 ml of different anion-containing water of varying concentrations. It is presumed, at this low pH, that only SeO42− remained as a divalent anion, while monovalent species H2AsO4− and HCrO4− predominated in their respective exchanging ion solutions. The adsorption data were fitted using the Freundlich equation and maximum adsorption for each anion was estimated using their respective Freundlich equation constants. MCC-AE exhibited preference for divalent Cr (VI) and Se (VI) anions compared with the Cl− resident ion. Maximum As (V) adsorption was 0.086 mmol/g, while maximum adsorption of Cr (VI), NO3− and Se (VI) anions was 0.327 mmol/g, 0.459 mmol/g, and 0.222 mmol/g, respectively. The ion exchange capacity of MCC-AE is estimated, based on its exchange capacity for nitrate, to be within 0.46 mmol of positive charges per gram. Similar adsorption experiments were conducted for comparison using commercial chloride-form Amberlite IRA-900 strong base (quaternary amine functionality) anion exchanger, with an exchange capacity of 4.2 meq/g. Maximum adsorption of the different ions in IRA-900 was about 3 times higher for NO3−, 9 times higher for Se (VI), 10 times higher for As (V) and 9 times higher for Cr (VI), than that in MCC-AE. Differences in the ion exchange behavior of MCC-AE and IRA-900 were probably due to the different amine functionalities in the two exchangers. The results suggest that MCC-AE may be used as a low-cost alternative adsorbent/ion exchanger for treatment of anion contaminants in groundwater.

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