scholarly journals Cesium Sorption and Desorption on Glauconite, Bentonite, Zeolite and Diatomite

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 625 ◽  
Author(s):  
Petr Belousov ◽  
Anna Semenkova ◽  
Tolganay Egorova ◽  
Anna Romanchuk ◽  
Sergey Zakusin ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
High Purity ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Cesium Sorption ◽  
Wide Ph Range ◽  
High Layer ◽  
Ph Range ◽  
Sorption Mechanisms ◽  
Sorption Characteristics

This study is devoted to studying the sorption of 137Cs on mineral sorbents at a wide pH range, from 2 to 10, as well as to studying sorption mechanisms. In order to obtain the most reliable sorption characteristics, samples of high purity were examined as sorbents: bentonite, glauconite, zeolite, and diatomite. A detailed description of their mineral composition, cation exchange capacity and specific surface of sorbents is given. XRD, XRF, FTIR, SEM, and BET adsorption methods were used for assaying. The sorption and desorption values were identified for each sorbent. As a result of the conducted research, it can be concluded that 137Cs sorption mainly occurs through the exchange reaction on zeolite, glauconite and bentonite. The highest cesium Kd was observed on zeolite due to its high CEC and amounted to 4.05 mg/L at pH 7. The higher sorption capacity of glauconite in comparison with bentonite is primarily due to the high layer charge which is mainly localized in tetrahedral sheets, and to the existence of highly selective sorption sites (frayed edge sites) on the glauconite surface. Diatomite showed the lowest sorption capacity provided by the presence of a small quantity of smectite and kaolinite in its composition. The values of desorption increase in the following order: zeolite < bentonite ~ diatomite < glauconite.

Effect of pH on the cation exchange capacity of some halloysite nanotubes

Clay Minerals ◽  
2016 ◽  
Vol 51 (3) ◽  
pp. 373-383 ◽  
Author(s):  
Nia Gray ◽  
David G. Lumsdon ◽  
Stephen Hillier
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Halloysite Nanotubes ◽  
Exchange Capacity ◽  
Average Value ◽  
Two Samples ◽  
Wide Ph Range ◽  
Capacitance Model ◽  
Ph Dependent ◽  
Ph Range

AbstractThe cation exchange capacity (CEC) of seven well characterized halloysite nanotubes (HNTs) in the dehydrated 7 Å form has been measured using a method based on cobalt hexammine exchange. In addition to unbuffered measurements, which varied between 2.9 and 9.3 cmol(+)kg−1, CECs were also determined over a wide pH range and proton titration measurements were conducted on two samples. The data were fitted using a constant capacitance model based on the presence of two sites: permanently charged sites and pH-dependent variable charged sites. Normalization of CEC to the average specific surface area (BET) of the halloysite samples reduces considerably the variation of CEC values for the different samples particularly over the intermediate pH range (5–9) with the average value at pH 7 equal to 8.5 cmol(+)kg−1and a standard deviation of 1.17. Overall the CEC behaviour of the seven samples appears reasonably consistent throughout the set. Calculations based on proton titrations suggest a ratio of variable charge to basal sites for the dehydrated halloysite nanotubes of ∼3:1.

Use of bentonite to control the release of copper from contaminated soils

Soil Research ◽  
2007 ◽  
Vol 45 (8) ◽  
pp. 618 ◽  
Author(s):  
Wanting Ling ◽  
Qing Shen ◽  
Yanzheng Gao ◽  
Xiaohong Gu ◽  
Zhipeng Yang
Keyword(s):  
Heavy Metals ◽  
Sorption Capacity ◽  
Contaminated Soils ◽  
Montmorillonite Clay ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Wide Ph Range ◽  
Ph Dependent ◽  
Ph Range ◽  
Soil Ageing

A decrease in release and availability of heavy metals in soil has been of worldwide interest in recent years. Bentonite is a type of expandable montmorillonite clay, and has strong sorption for heavy metals. In this work, the control of amended bentonite on the release of copper (Cu2+) from spiked soils was investigated using a batch equilibrium technique. Sorption of Cu by bentonite was pH-dependent, and could be well described using the Langmiur model. Maximum sorption capacity of the bentonite used in this study was 5.4 mg/g, which was much greater than soils reported in the literature. The extent of Cu2+ release from spiked soils was correlated with slurry concentrations, pH, and soil ageing process. In all cases, the amendment of bentonite was observed to effectively decrease the release of Cu2+ from soils. The apparent aqueous concentrations of Cu2+ released from soils devoid of bentonite treatment were 113–1160% higher than those from the soils amended with bentonite. Moreover, the magnitude of Cu2+ release decreased with increasing amount of bentonite added to soils. The bentonite added was more effective in retaining Cu2+ in sorbents for aged contaminated soils. Such enhanced retention resulting from the presence of bentonite was observed within a wide pH range from 2.5 to 7.0. Bentonite, as one of the most abundant minerals in soils, is regarded to improve the soil overall quality. The results obtained from this work provide useful information on utilisation of bentonite to control the release of heavy metals from contaminated soils.

scholarly journals Planting trees and amending with waste increases the capacity of mine tailings soils to retain Ni, Pb and Zn

2014 ◽  
Vol 4 ◽  
Author(s):  
Verónica Asensio Fandiño ◽  
Flora A. Vega ◽  
Rubén Forján ◽  
Emma F. Covelo
Keyword(s):  
Sorption Capacity ◽  
Soil Ph ◽  
Mine Tailings ◽  
Cation Exchange Capacity ◽  
Inorganic Carbon ◽  
Exchange Capacity ◽  
Tree Planting ◽  
Batch Adsorption ◽  
Organic And Inorganic Carbon ◽  
High Concentrations

The sorption capacity for Ni, Pb and Zn of mine tailings soil with and without reclamation treatment (tree planting and waste amendment) was evaluated using the batch adsorption technique. It is important to determine the capacity of waste-amended soils to retain Ni, Pb and Zn, as the sludges used usually have high concentrations of these metals. The results obtained in the present study showed that the untreated mine tailings soil had a low capacity for Ni, Pb and Zn retention. The sorption capacity for Pb increased significantly in all of the treated soils, without any significant differences between them. The treatment that most increased the sorption capacity for Ni and Zn was planting with trees and amending with waste simultaneously, as this increased the concentration of both organic and inorganic carbon, exchangeable calcium, soil pH and effective cation exchange capacity

Sorption of Anionic Pentachlorophenol (PCP) in Aquatic Environments: The Effect of pH

1992 ◽  
Vol 25 (11) ◽  
pp. 41-48 ◽  
Author(s):  
Y. Shimizu ◽  
S. Yamazaki ◽  
Y. Terashima
Keyword(s):  
Organic Carbon ◽  
Aqueous Phase ◽  
Cation Exchange Capacity ◽  
Clay Content ◽  
Exchange Capacity ◽  
Poor Correlation ◽  
Aquatic Environments ◽  
Organic Carbon Content ◽  
Swelling Clay ◽  
Ph Range

The sorption of pentachlorophenol (PCP, pKa’ = 4.75) onto natural solids from aqueous phase was investigated by batch sorption experiments. The experimental aqueous phase was prepared for set values of pH (2 to 12) and ionic strength (0.1 M). Experimental results indicated that the sorption decreased with increasing pH over the entire pH range tested. A simple mathematical model, based on the hypotheses that the sorption coefficients of non-ionized and ionized species are different and the pH has only negligible effect on the natural solid characteristics, was applied to the pH range between 6 and 8, and the sorption coefficients (Kd) of both species were estimated. The Kd of ionized species (phenolate anion) was smaller than that of non-ionized species. The Kd of both species had poor correlation to the organic carbon content of natural solids. The Kd, however, correlated well with the swelling clay content and cation exchange capacity of natural solids. These results indicated that the sorption of PCP was not controlled by the organic carbon referenced hydrophobic sorption. For broader pH range (i.e., below 6 or above 8), the dependence of the natural solid characteristics on pH must be additionally included in the model.

scholarly journals Synthesis and Characterization of Organic-Inorganic Nanocomposite Poly-o-anisidine Sn(IV) Arsenophosphate: Its Analytical Applications as Pb(II) Ion-Selective Membrane Electrode

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Asif Ali Khan ◽  
Umme Habiba ◽  
Anish Khan
Keyword(s):  
Environmental Pollutant ◽  
Exchange Capacity ◽  
Indicator Electrode ◽  
Membrane Electrode ◽  
Mixed Solution ◽  
Electroactive Material ◽  
Wide Ph Range ◽  
Selective Membrane ◽  
Distribution Studies ◽  
Ph Range

Poly-o-anisidine Sn(IV) arsenophosphate is a newly synthesized nanocomposite material and has been characterized on the basis of its chemical composition, ion exchange capacity, TGA-DTA, FTIR, X-RAY, SEM, and TEM studies. On the basis of distribution studies, the exchanger was found to be highly selective for lead that is an environmental pollutant. For the detection of lead in water a heterogeneous precipitate based ion-selective membrane electrode was developed by means of this composite cation exchanger as electroactive material. The membrane electrode is mechanically stable, with a quick response time, and can be operated over a wide pH range. The selectivity coefficients were determined by mixed solution method and revealed that the electrode is sensitive for Pb(II) in presence of interfering cations. The practical utility of this membrane electrode has been established by employing it as an indicator electrode in the potentiometric titration of Pb(II).

scholarly journals Influence of water washing treatment on Ulva prolifera-derived biochar properties and sorption characteristics of ofloxacin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chenghu Yang ◽  
Shichao Miao ◽  
Tiejun Li
Keyword(s):  
Sorption Capacity ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Ulva Prolifera ◽  
Solution Temperature ◽  
Solution Ph ◽  
Water Washing ◽  
Influence Of Water ◽  
Sorption Mechanisms ◽  
Sorption Characteristics

AbstractThe influences of water washing treatment on the properties of Ulva prolifera-derived biochar (U.P-biochar) and its sorption characteristics of ofloxacin (OFL) were investigated. The results showed that the water washing treatment significantly changed the physiochemical structures of U.P-biochars, and improved the sorption capacity of OFL. The sorption capacity of OFL by U.P-biochar was closely dependent on pyrolysis temperature (200–600 °C) and equilibrium solution pH (3–11). Different sorption mechanisms (e.g. cation exchange, electrostatic attraction, H-bond and cationic–π and π–π interactions) were dominant for specific U.P-biochars under various pH regions (acidic, neutral and alkaline). Moreover, the unwashed and washed U.P-biochars prepared at 200 °C (BC200 and BCW200) showed a higher sorption capacity of OFL at pH = 7. The two-compartment first-order model provided an appropriate description of the sorption kinetics of OFL by BC200 and BCW200 (R2 > 0.98), which revealed that the contribution ratios between the fast and slow sorption compartments (ffast/fslow, 1.55 for BC200 and 1.25 for BCW200) reduced after water washing treatment of U.P-biochar. The values of n for the Freundlich model were less than 1, which demonstrated that the sorption of OFL by BC200 and BCW200 was favourable and nonlinear. Also, the sorption of OFL by BC200 and BCW200 increased with an increase in solution temperature and the sorption process was spontaneous and endothermic. This study provides valuable information for being a primary consideration in the production and application of U.P-biochar.

EVALUASI PERUBAHAN KUALITAS TANAH PADA LAHAN BEKAS PENAMBANGAN NIKEL DI PULAU GEBE

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Mardi Wibowo
Keyword(s):  
Organic Carbon ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Mining Activity ◽  
Evaluation Activity ◽  
Land Quality ◽  
Environment Quality

Since year 1977 until 2005, PT. ANTAM has been exploited nickel ore resources at Gebe Island – Center ofHalmahera District – North Maluku Province. Mining activity, beside give economically advantages also causedegradation of environment quality espicially land quality. Therefore, it need evaluation activity for change ofland quality at Gebe Island after mining activity.From chemical rehabilitation aspect, post mining land and rehabilitation land indacate very lack and lackfertility (base saturated 45,87 – 99,6%; cation exchange capacity 9,43 – 12,43%; Organic Carbon 1,12 –2,31%). From availability of nutrirnt element aspect, post mining land and rehabilitation land indicate verylack and lack fertility (nitrogen 0,1 – 1,19%). Base on that data, it can be concluded that land reclamationactivity not yet achieve standart condition of chemical land.Key words : land quality, post mining lan

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