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

Author(s):  
Liudmila Kolmykova ◽  
Valentina Nikashina ◽  
Elena Korobova

<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>

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4359
Author(s):  
Jacek Leszczyński

This study investigated the use of weathered halloysite as an ion exchange material for ammonium removal from water. The study was conducted under static and dynamic conditions. The influence of such parameters as the preliminary concentration of ammonium ions, dose of halloysite, and pH was examined in periodic studies. The ion exchange capacity of weathered halloysite under various regeneration conditions such as concentration, excess of regeneration solution and the pH at which the regeneration was performed was also determined. The effect of flow velocity, initial NH4+-ions concentration was studied in column tests and the weathered halloysite’s ion -exchange capacity was also determined. The best results of ammonium ion removal were obtained at pH 6. The equilibrium isotherms were described using the Langmuir and Freundlich models. The results of periodic studies show a good fit for the data of both models, with Langmuir isotherms reflecting the removal of ammonium ions better. A good match for the data (R2 > 0.99) was provided by a pseudo second-order kinetic model. The obtained results indicate that a properly prepared halloysite can be a useful mineral for the removal of dangerous substances, such as ammonium ions, present in natural waters.


1992 ◽  
Vol 57 (9) ◽  
pp. 1905-1914
Author(s):  
Miroslav Bleha ◽  
Věra Šumberová

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.


2005 ◽  
Vol 51 (11) ◽  
pp. 63-70 ◽  
Author(s):  
H. Inan ◽  
B. Beler Baykal

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.


2021 ◽  
Vol 37 (2) ◽  
pp. 388-396
Author(s):  
Preethab B

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.


2013 ◽  
Vol 652-654 ◽  
pp. 1704-1709
Author(s):  
Qiong Qiong Liu ◽  
Xin Tan ◽  
Xiao Long Shao

The object of this research is to investigate the removal of nitrogen in the form of ammonium ion (NH4+-N) from aqueous solutions using Na-form of high-performance ammonium ion-exchange material. The Chinese Kaolin from the province of Guangzhou is used as the raw material and modified to prepare the ion-exchange materials. According to CEC measurement, the obtained ammonium ion-exchange material had an ammonium ion exchange capacity greater than 75mgNH4+-N/g and can be used to remove ammonia nitrogen in water treatment. In this paper, several surface feature evaluation methods(SEM、XPS、IR)are used to discuss and analyze the modification process of kaolin and the action mechanism and modification results of the ammonia ion exchange material.


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