Interaction of aqueous acidic-fluoride waste with natural Tunisian soil
Hamdi, Noureddine (Technopole de Borj Cedria. Unité Matériaux.)
Srasra, Ezzedine (Technopole de Borj Cedria. Unité Matériaux)
Date: |
2008 |
Abstract: |
Clayey soils are essential materials used to reduce hydraulic conductivity and pollutant migration, common at sites of waste disposal. This study investigates the possible use of a Tunisian soil as a lining material for disposal sites for acidic-fluoride wastes. A permeability test oa a waste-solution sample (pH = 2. 7) obtained from a disposal site in southern Tunisia was conducted over a period of about 2 years. The test results show that the permeability decreased with time until stabilized at 8. 33 × 10 m/s. After the permeability test, the samples retrieved from the permeameter show a degradation state which varied with the thickness of the specimen. These samples can be classified into three zones (Z1: unaffected, Z2: moderately affected; and Z3: extensively affected). Physicochemical characterization of the three samples (Z1, Z2, and Z3), and of the original argillaceous soil, was by X-ray diffraction, Fourier transform infrared spectroscopy, differential thermal and thermal gravimetric analysis, Si and Al nuclear magnetic resonance, and N-adsorption techniques. The original sample consists essentially of palygorskite, kaolinite, and quartz. Sample Z3 underwent complete dissolution of kaolinite which supports the precipitation of fluoroaluminate and the appearance of an X-ray amorphous silica phase. In samples Z1 and Z2, the soil adsorbs fluoride at a rate of ∼68. 5 mg/g and is highly resistant to acidic attack. |
Rights: |
Tots els drets reservats. |
Language: |
Anglès |
Document: |
Article ; recerca ; Versió publicada |
Subject: |
Acidic-fluoride Waste Storage ;
DTA-TG ;
FTIR ;
Permeability ;
Si and Al NMR ;
XRD |
Published in: |
Clays and Clay Minerals, Vol. 56, Núm. 2 (2008) , p. 259-271, ISSN 1552-8367 |
DOI: 10.1346/CCMN.2008.0560209
13 p, 1.3 MB
UAB restricted access
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Record created 2020-06-10, last modified 2023-06-03