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)

Data:	2008
Resum:	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.
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Acidic-fluoride Waste Storage ; DTA-TG ; FTIR ; Permeability ; Si and Al NMR ; XRD
Publicat a:	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  Accés restringit a la UAB

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