Np(V) uptake by various clays

Semenkova, Anna; Romanchuk, Anna Yu.; Krupskaya, V. V.; Pokidko, B. V.; Dorzhieva, O. V.; Sobolev, A. V.; Presnyakov, I. A.; Verma, Parveen K.; Mohapatra, P. Κ.; Kalmykov, Stepan N.

doi:10.1016/j.apgeochem.2018.02.006

Cited by 9 publications

(1 citation statement)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sorption capacity of bentonite clays towards these pollutants depends on their composition and varies in clays from different deposits [2][3][4][5][6][7][8][9][10][11][12]. It was demonstrated that depending on the pH, ionic strength, composition of the solution and the conditions of the experiments, bentonites with different mineral composition and physical properties, adsorb from 13.2 to 32.7 mg Cu 2+ per gram clay [13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2020

View full text Add to dashboard Cite

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.

show abstract