The investigation on cationic exchange capacity of zeolites: The use as selective ion trappers in the electrokinetic soil technique

2006 ◽  
Vol 137 (2) ◽  
pp. 1079-1088 ◽  
Author(s):  
Ornella Ursini ◽  
Edo Lilla ◽  
Roberta Montanari
2012 ◽  
Vol 510 ◽  
pp. 757-761 ◽  
Author(s):  
Shu’e Duan ◽  
Yun Hui Zhai ◽  
Ying Juan Qu

In this paper a novel colorless and salt-tolerant silver-histidine complex doped montmorillonite (Na-MMT) antibacterial agent (SHMMT) power was synthesized by ion exchange reaction using silver-histidine complex ion [Ag (his)] + as precursor, and characterized by atomic absorption spectrophotometer (AAS) and power X-ray diffraction (XRD). The antibacterial activities against Pseudoalteromonas carrageenovora were examined by a modified broth dilution test and the plate counting method. The salt-tolerant property was determined by the antibacterial activities of the sea water soaked SHMMT. The results showed that the Ag loading amount of SHMMT powder reached 1.7mmol/g, far more than the cationic exchange capacity (CEC) of Na-MMT. SHMMT powder had high bacterial activity eventhough it was soaked in the sea water for 30 days. 1


Cerâmica ◽  
2001 ◽  
Vol 47 (301) ◽  
pp. 4-8 ◽  
Author(s):  
C. Volzone ◽  
L. B. Garrido

Rheological changes were found in smectite (Wyoming- and Cheto-type montmorillonites) suspensions after structural modifications. The effect of the particle size and Na+ exchange on the flow curves of 6% wt/wt suspensions of smectites with and without Na2CO3 were examined. Mineralogical, structural and physicochemical characteristics were studied by X-ray diffraction (XRD), infrared spectroscopy (IR), cationic exchange capacity (CEC), Mg2+, Al3+ determinations, particle size distribution and swelling index (SI). Grinding in an oscillating mill modified the particle sizes. The montmorillonite grain size and the structural disorder increased after larger grinding times. The grinding treatment modified the apparent viscosity and the yield stress of the montmorillonite suspensions. The homoionic Na Cheto-type montmorillonite with fine particle size (obtained by grinding) increased the flow properties. Nevertheless, rheological properties were lower than those of suspensions of the Wyoming-type montmorillonite. Montmorillonite-types reacted differently with Na2CO3 additions and this behavior may be related to their structural composition. The Na2CO3 activation improved the flow properties of the original Wyoming-type montmorillonite and after 30 s grinding.


Cerâmica ◽  
2017 ◽  
Vol 63 (366) ◽  
pp. 253-262 ◽  
Author(s):  
N. I. Alvarez Acevedo ◽  
M. C. G. Rocha ◽  
L. C. Bertolino

Abstract Characterization studies of clays are often performed to identify possible markets for these materials. Bearing this in mind, two samples of natural clays from the Southeast region of Brazil were studied. Conventional techniques of characterization were used. Granulometric analysis and determination of cationic exchange capacity of these clays were also performed. Nitrogen adsorption-desorption measurements were used to determine the Brunauer-Emmett-Teller specific surface area, and Barrett-Joyner-Halenda and t-plot pore size analysis were carried out. The results obtained were similar for the two clays. Both present high clay fraction (above 80 wt%) composed of illite, kaolinite and quartz minerals. Stratified illite-smectite structures were also observed. Traces of calcite were detected in one of the clay samples, while traces of montmorillonite were observed in the other sample. These results were corroborated by the low cationic exchange capacity values obtained for both clays. These clays showed good adsorptive properties, evidenced by their specific surface areas, with predominantly mesoporous structures and slit-like pores. According to their features, these clays have potential use as adsorbents to replace more expensive materials due to their easy availability and low cost.


2020 ◽  
Vol 3 (2) ◽  
pp. 71
Author(s):  
Irvan Maulana Firdaus ◽  
Diva N.M.D. Masyitoh ◽  
Tharra A.N. Azizah ◽  
Febiyanto Febiyanto

<p><em>This study investigated the electrolyte property of humus-contained andosol soil using Volta cell. The electrodes that are used were Cu and Zn for cathode and anode, respectively. This research was done by varying electrode area and distance between Cu and Zn electrodes. The varied electrode area was 20, 30, and 40 cm<sup>2</sup>, whereas the electrode distance was 3, 4, and 5 cm. Then, the current and voltage profiles of Volta cell system were measured using a digital multimeter. The result showed that humus-contained andosol soil has an electrolyte property. Electrolyte property of andosol soil might be due to the humus substance that has a high cationic-exchange capacity. Besides, it showed that the increase of the electrode area, the current and voltage were increased gradually. In contrast, the increase in current and voltage could be found by the decrease of electrode distance. In addition, the use of 24-Volta cells system enhancing current and voltage compared to a single cell. It suggests that the increase of current and voltage was relatively proportional to the number of Volta cell. Therefore, this research can be a reference for the identification of electrolyte property of natural or waste materials.</em></p>


2016 ◽  
Vol 10 (2) ◽  
pp. 116
Author(s):  
Edi Pramono ◽  
Candra Purnawan ◽  
Yuniawan Hidayat ◽  
Jati Wulansari ◽  
Sayekti Wahyuningsih

Research on the preparation and characterization of sulfonated polystyrene (PST) /chitosan vanillin (KV) composite as electrolyte membranes has been conducted in order to investigate the effect of PST and KV composition  to its chemical and physical properties. Polystyrene was modified by sulfonation reaction to produces PST<strong>, </strong>meanwhile chitosan was modified by schift base reaction to produces KV. The composite membranes were prepared by casting method and were characterized in order to identify the functional groups contained in the composite, the cation exchange capacity (CEC), the Swelling Degree (SD), the thermal properties and the morphology. The peak of imine vibration in the FTIR spectrum indicates that the chitosan vanilin was succesfully synthesized. Meanwhile, the peak of sulfonate vibration indicates the product of sulfonation on polystyrene. The result of CEC analysis shows that the addition of sulfonate groups on polystyrene and the addition of phenolic groups on chitosan increase the CEC value. The increasing of PST and KV concentration in membrane enhance the CEC value. However, the increasing of PST concentration in membrane composition even decrease the Swelling Degree of membranes. Meanwhile, the increasing of KV concentration increase the swelling degree of membranes. Thermal analysis shows that the thermal decomposition of membranes occurs in three stages i.e. the dehydration of water molecules, the degradation of the subtituen groups and the plasticizer and the degradation of the back bone of chitosan and polystyrene.


2012 ◽  
Vol 727-728 ◽  
pp. 1451-1456
Author(s):  
Andréa Lopes Silva ◽  
Francisco Kegenaldo Alves de Souza ◽  
Gelmires Araújo Neves ◽  
Romualdo Rodrigues Menezes ◽  
Hélio Lucena Lira ◽  
...  

Organically modified clay minerals are widely used as sorbents for hydrophobic organic compounds e.g., organic pollutants treatment from water solutions. Natural clay materials are hydrophilic and therefore they are not efficient sorbents for organic compounds. Intercalations of natural clay materials, with organic cations, with quaternary ammonium groups may become these clays hydrophobic. Vermiculite is the mineralogical name given to hydrated laminar magnesium-aluminum-iron silicate; this natural clay was modified and used for the production of organically modified clay (organovermiculite), with the purpose of its use in removing organic contaminants. The organovermiculite was prepared using different concentrations of distearyl dimethyl ammonium chloride (praepagen) based on cationic exchange capacity of the clay. It was evident from the X-ray diffraction that the salt was incorporated to the clay structure confirming its organophilization and through the Foster swelling test it was observed the affinity between the organic pollutants and the organovermiculite.


2021 ◽  
Vol 43 ◽  
pp. e50164
Author(s):  
Germano Leão Demolin Leite ◽  
Ronnie Von Santos Veloso ◽  
André Luis Matioli ◽  
Chrystian Iezid Maia e Almeida Feres ◽  
Marcus Alvarenga Soares ◽  
...  

. The objective was to study the habitat complexity of mite populations on Caryocar brasiliense trees under natural and cultivated field conditions. The study was performed in the municipality of Montes Claros, in the state of Minas Gerais, Brazil, over 3 years. Three types of areas were studied: 1) Cerrado, 2) pasture, and 3) a university Campus. Several chlorotic spots were detected on leaves with larger populations of Tetranychus sp. and Eutetranychus sp. (Tetranychidae). The greatest numbers of Agistemus sp. (Stigmaeidae) on leaves and Histiostoma sp. (Histiostomidae) and Proctolaelaps sp. (Ascidae) on fruits were observed in the pasture, and that of Histiostoma sp. on leaves in the pasture and on the university Campus. In general, the herbivorous mites (e.g., Tetranychus sp.) found on C. brasiliense plants were correlated with more clayey soils with a higher cationic exchange capacity; larger populations of mites (e.g., Agistemus sp. and Histiostoma sp.) were found on the C. brasiliense trees with the largest crown sizes; and associations between predator mites (e.g., Agistemus sp.) and phytophagous mites (e.g., Tetranychus sp.1) were observed. Greater habitat diversity and more complex plant architectures favored the mite populations. The positive effect of loamier soil on herbivorous mites indicates that these species are adapted to Cerrado conditions. Some recorded species of herbivorous mites can be pests in commercial plantations of C. brasiliense.


Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1327
Author(s):  
Leandro Oliveira ◽  
Josy Osajima ◽  
Ramon Raudel Peña-Garcia ◽  
Edson Cavalcanti Silva-Filho ◽  
Maria Gardennia Fonseca

The presence of drugs in aquatic bodies is a prevailing issue, and their removal by adsorption is an effective treatment. Among the adsorbents, those based clay minerals have been proposed. Bentonite is a clay mineral that is widely studied as an adsorbent due to its unique physicochemical properties, such as cation exchange capacity (CEC), intercalation, and adsorption. The properties of bentonites can be improved through chemical modifications, such as the incorporation of organic and/or inorganic compounds. These modifications allow for the efficient removal of different contaminants, including pharmaceutical compounds. In this work, raw sodium bentonite (Na+-Bent) and vanadyl bentonites were prepared using 100 (BentV1), 300 (BentV3), and 500% (BentV5) of the cationic exchange capacity of the Na+-Bent and further used for amiloride removal from aqueous solution. Analysis of X-ray fluorescence and Na+ in solution after interaction indicated that the principal mechanism of interaction between bentonite and ions was the ion exchange between sodium of the matrix and vanadyl in solution. Infrared spectroscopy suggested the contribution of coordination of the interlayer water with the vanadyl ions and hydrogen bonding between vanadyl and structural OH. X-ray diffraction analysis indicated that vanadyl ions were incorporated onto Na+-Bent. Amiloride adsorption was better at pH 5.8, using a solid dosage of 75 mg of Na+-Bent, 25 mg of BentV1 and BentV5, and 50 mg of BentV3. The adsorption occurred briefly until 20 min, and maximum removal values were 457.08, 374.64, 102.56, and 25.63 mg·g−1 for Na+-Bent, BentV1, BentV3, and BentV5, respectively. At lower drug concentrations (48.78 and 91.24 mg·g−1 for Na+-Bent and BentV3), the best performance was obtained for the BentV3 sample.


1986 ◽  
Vol 18 (4-5) ◽  
pp. 83-92 ◽  
Author(s):  
J. M. Martin ◽  
J. M. Mouchel ◽  
P. Nirel

Estuaries and coastal zones are characterised by very varied chemical and physical environments. As a result, heterogenous reactions predominate between dissolved and mineral phases, and with the biota. These reactions primarily affect elements and compounds located at the particulate surface. Thus the determination of surface properties of particles is an important key to understanding interactions of trace elements and organic compounds between particulate and dissolved phases in estuarine and coastal systems. Specific surface area (SSA), cationic exchange capacity (CEC) and heat of immersion (∆H) have been measured on native untreated suspended sediment and after oxidation with 15% H2O2. SSA and ∆H have also been measured on samples Leached with NaOH and Na-dithionite in order to remove amorphous aluminosilicates. Results indicated that SSA is controlled by amorphous oxides and is related to the Al content of samples and their granulometry, suggesting an almost uniform coating of the detrital core by amorphous oxides. On the other hand, CEC and ∆H, which appear to be highly correlated, are controlled by both organic matter and amorphous oxides. Studies on electrophoretic mobility have provided additional data on the excess of charge at the interface between suspended matter and electrolytic medium. Particles in suspension in fresh, sea, and estuarine waters appear ubiquitously to exhibit a small range of negative surface charge. This uniformity is attributed to the presence of organic surface coatings on the particles (Loder and Liss, 1985). Finally, the significance of organic and oxide coatings as carriers of trace metal pollutants is discussed. It is shown that their importance in terms of flux is usually Low despite their major role in controlling solid-liquid interactions.


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