scholarly journals Sorption of Cu2+ Ions by Bentonite Modified with Al Keggin Cations and Humic Acid in Solutions with pH 4.5

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1121
Author(s):  
Yulia Izosimova ◽  
Inna Tolpeshta ◽  
Irina Gurova ◽  
Michail Karpukhin ◽  
Sergey Zakusin ◽  
...  

The sorption of Cu2+ onto bentonite modified with Al Keggin cations and humic acid from CuCl2 solutions at pH 4.5 was studied. Modification of Na-bentonite with Al Keggin cations was found to result in an increase in the basal spacing of montmorillonite from 1.29 nm for N-form to 1.85 and 1.78 nm for HAl13 and Al13 forms respectively, in a reduction of CEC (cation exchange capacity) and in the formation of additional sites with a variable charge with pHPZC 4.2. Al13-bentonite is not affected by heat. Under the conditions of the experiments at pH of 4.5 Na-bentonite adsorbs more Cu2+ from CuCl2 solutions then Al13 forms of bentonites. The main mechanism of copper sorption on Na-bentonite is the cation exchange Cu2+–Na+. The reduction of CEC of Na-bentonite after modification with Al Keggin cations leads to a decrease in the Cu2+ sorption. pH-dependent sorption sites on Al13-bentonites have a pHPZC of 4.2 and, therefore, under conditions of the experiment have positive charge which prevents Cu2+ sorption. Na-bentonite adsorbs more humic acid solution (HA) then Al13-bentonite and the proportion of adsorbed HA remains constant over the entire concentration range. Treatment of the Al13-bentonite with HA leads to the formation of the additional sorption sites. The amount of sorbed Cu2+ and the percentage of their extraction from solutions by HAAl13-bentonite is similar to those values for Na-bentonite.

1977 ◽  
Vol 57 (3) ◽  
pp. 233-247 ◽  
Author(s):  
ROGER W. BARIL ◽  
THI SEN TRAN

Correlations were made among chemical criteria used for taxonomic soil classificaton. The compared tests were: oxalate Δ (Fe + Al), pyrophosphate-extractable (Fe + Al), oxalate-extractable Al, pH-dependent cation exchange capacity (ΔCEC), ratios of pyrophosphate-extractable (Fe + Al) over clay or over dithionite-extractable (Fe + Al), and finally soil pH measured in 1 M NaF. Significant correlations were found among various measured parameters. However, no single test was found to be reliable as a single criterion when applied to the taxonomic classification of Quebec soils. The two chemical tests, pyrophosphate-extractable (Fe + Al) and its ratio over clay, combined with morphologic criteria appeared useful for classifying Quebec Podzols. A few soils, which presented discrepancies from chemical criteria were found difficult to classify, thus suggesting the possibility of establishing new sub-groups in the Canadain soil taxonomic classification system.


Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 3015
Author(s):  
Fethi Kooli ◽  
Souad Rakass ◽  
Yan Liu ◽  
Mostafa Abboudi ◽  
Hicham Oudghiri Hassani ◽  
...  

The effect of the counteranion of hexadecyltrimethylammonium salts on the physico-chemical properties of organoclays was investigated, using a selected natural clay mineral with a cation exchange capacity of 95 meq/100 g. The uptake amount of C16 cations was dependent on the hexadecyltrimethylammonium (C16) salt solution used, the organoclay prepared from C16Br salt solution exhibited a value of 1. 05 mmole/g higher than those prepared from C16Cl and C16OH salt solutions. The basal spacing of these organoclays was in the range of 1.81 nm to 2.10 nm, indicating a similar orientation of the intercalated surfactants, and could indicated that the excess amount of surfactants, above the cation exchange capacity of 0.95 meq/g could be adsorbed on the external surface of the clay mineral sheets. These organoclays were found to be stable in neutral, acidic, and basic media. The thermal stability of these organoclays was carried out using thermogravimetric analysis and in-situ X-ray diffraction (XRD) techniques. The decomposition of the surfactant occurred at a maximum temperature of 240 °C, accompanied with a decrease of the basal spacing value close to 1.42 nm. The application of these organoclays was investigated to remove an acidic dye, eosin. The removal amount was related to the initial used concentrations, the amount of the surfactants contents, and to the preheated temperatures of the organoclays. The removal was found to be endothermic process with a maximum amount of 55 mg of eosin/g of organoclay. The value decreased to 25 mg/g, when the intercalated surfactants were decomposed. The reuse of these organoclays was limited to four regeneration recycles with a reduction of 20 to 30%. However, noticeable reduction between 35% to 50% of the initial efficiency, was achieved after the fifth cycle, depending of the used organoclays.


1968 ◽  
Vol 48 (1) ◽  
pp. 53-63 ◽  
Author(s):  
J. S. Clark ◽  
W. E. Nichol

Heating in hydrogen peroxide, dilute oxalic acid, and dilute aluminum oxalate did not change the effective cation exchange capacity (CEC) or the pH-7 CEC of Wyoming bentonite and Alberni clay soil containing excess Al(OH)x. This indicated that treatment of soils with H2O2 to oxidize organic matter and the possible production of oxalates during oxidation did not change the CEC values of the inorganic fraction of soils even if some clay exchange sites were blocked by hydrous oxides of Al.With soils of pH less than approximately 5.4, oxidation of organic matter did not change the effective CECs although the pH-7 CEC values were decreased. Thus, organic matter in acid soils appeared to have little or no effective CEC. Because of this and the negligible effect of H2O2 oxidation on the CEC values of clays, the difference of the pH-7 CEC of soils before and after H2O2 oxidation provided a simple means of estimating the amount of organic pH-dependent CEC in acid soils.The amount of organically derived pH-dependent CEC was determined in a number of soils by means of peroxide oxidation. The technique provided a useful indication of the quantities of sesquioxide–organic matter complexes accumulated in medium- and fine-textured soils.


Soil Science ◽  
1970 ◽  
Vol 109 (5) ◽  
pp. 272-278 ◽  
Author(s):  
B. L. SAWHNEY ◽  
C. R. FRINK ◽  
D. E. HILL

Chemosphere ◽  
1998 ◽  
Vol 36 (10) ◽  
pp. 2283-2290 ◽  
Author(s):  
P. Warwick ◽  
A. Hall ◽  
V. Pashley ◽  
J. Van der Lee ◽  
A. Maes

Author(s):  
Resman ◽  
Sahta Ginting ◽  
Muhammad Tufaila ◽  
Fransiscus Suramas Rembon ◽  
Halim

The research aimed to determine the effectiveness of compost containing humic and fulvic acids, and pure humic and fulvic acids in increasing of Ultisol soil chemical properties. The research design used a randomized block design (RBD), consisting of 10 treatments, namely K0: 0 g polybag-1, KO1: 500 g polybag-1, KO2: 500 g polybag-1, KO3: 500 g polybag-1, KO4: 500 g polybag-1, KO5: 500 g polybag-1, KO6: 500 g polybag-1, KO7: 500 g of polybags-1, H: 50 g of polybag-1, A: 500 g polybag-1. Each treatment was repeated three times and obtained 30 treatment units. The results showed that pH H2O (K0: 4.49, KO1: 5.64, KO2: 5.47, KO3: 5.43, KO4: 5.51, KO5: 5.39, KO6: 5.48, KO7: 6.17, H: 5.06, F: 5.15), total-N (%) (K0: 0.13, KO1: 0.17, KO2: 0.18, KO3: 0.30, KO4: 0.25, KO5: 0.24, KO6: 0.29, KO7: 0.36, H: 0.16, F: 0.14), organic-C (%) (K0: 1.85, KO1; 2.30, KO2: 2.24, KO3: 2.33, KO4: 2.62, KO5: 2.25, KO6: 2.27, KO7: 2.95, H: 2.32, F: 2.26) , available-P (%) (K0: 2.75, KO1: 3.24, KO2: 3.16, KO3: 3.27, KO4: 3.57, KO5: 3.31, KO6: 3.37, KO7: 3.89, H: 3.10, F: 3.12), exchangeable-Al (me100g-1) (K0: 2.51, KO1: 2.11, KO2: 2.13, KO3: 2.15, KO4: 1.88, KO5: 2.14, KO6: 2.12, KO7: 1.75, H: 2.16, F: 2.17), base saturation (%) (K0: 30.91, KO1: 63.48, KO2: 52.63, KO3: 53.76, KO4: 56.13, KO5: 54.96, KO6: 56.71, KO7: 65.53, H: 39.11, F: 42.76), cation exchange capacity (me100g-1) (K0: 12.76, KO1: 15.64, KO2: 14.86, KO3: 14.35, KO4: 14.13, KO5: 15.01, KO6: 15.50, KO7: 17.94, H: 14.19, F: 13.73). The combined compost treatment of three types of organic matter (Imperata cylindrica + Rice straw + Glincidia sepium) is more effective in increasing the pH, H2O as 37.42%, total-N as 176.92%, Organic-C as 59.46%, available-P as 41.45%, base saturation as 65.53%, cation exchange capacity as 17.94% and exchangeable -Al, Alreduction as 30.28% of ultisol soil. KEY WORDS: compost, humic acid, fulvate, soil chemical, ultisol


Clay Minerals ◽  
1972 ◽  
Vol 9 (4) ◽  
pp. 425-433
Author(s):  
B. S. Kapoor

AbstractThe cation exchange capacity (C.E.C.) of nontronite was determined by titrating the acid clay, prepared by the action of H-resin on nontronite, in water and some nonaqueous solvents. The base-titratable acidities of the acid nontronite, freshly prepared as well as aged, were found to be greater than the acidities extractable with 1 N NaCl; the difference was attributed to the non-exchangeable pH-dependent component of C.E.C. In the freshly prepared sample, H+ and Fe3+ ions were the only exchangeable cations. Ageing produced basic Fe ions which were exchangeable and whose amount increased at the cost of H− and Fe3+ ions. Whatever the age, the total quantity of these exchangeable cations corresponding to the total isomorphous charge, remained constant. The amount of the pH-dependent acidity also remained unchanged. A likely mechanism to account for the observed pH-dependent component of the C.E.C, of nontronite is suggested.


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