Adsorption isotherm studies of chromium (VI) from aqueous solutions using sol-gel hydrotalcite-like compounds.
In under-developed countries, industries such as paint and pigment manufacturing, leather tanning, chrome plating and textile processing, usually discharge effluents containing Cr(VI) and Cr(III) into municipal sanitary sewers. It has been reported that Cr(VI) acts as a powerful epithelial irritant and as a human carcinogen. In the present work, hydrotalcite-like compounds with a Mg/Al ratio=2 were synthesized by the sol-gel method. The hydrotalcite-like compounds and their corresponding thermally treated products were characterized by powder X-ray diffraction, infrared spectroscopy and N(2) adsorption. The hydrotalcite-like compounds and the heated solids were used as adsorbents for Cr(VI) in aqueous solutions. Adsorption isotherm studies of Cr(VI) from aqueous solution are described. The adsorbent capacity was determined using the Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherm models. The Cr(VI) adsorption isotherm data fit best to the Langmuir isotherm model. The maximum Cr(VI) uptake by hydrotalcite and the heated solids was determined using the Langmuir equation and was found to range between 26 and 29 mg Cr(VI)/g adsorbent.
Ramos-Ramírez
Esthela
E
Centro de Investigaciones en Química Inorgánica de la Universidad de Guanajuato, CP 36050 Guanajuato, Gto, Mexico. ramosre@quijote.ugto.mx
Ortega
Norma L Gutiérrez
NL
Soto
Cesar A Contreras
CA
Gutiérrez
Maria T Olguín
MT
D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry / Q000302:isolation & purification*; D007220:Industrial Waste; D008276:Magnesium Hydroxide / Q000737:chemistry*; D044367:Phase Transition; D012996:Solutions; D013816:Thermodynamics
D007220:Industrial Waste; D012996:Solutions; D002857:Chromium; C010467:hydrotalcite; C074702:chromium hexavalent ion; D000536:Aluminum Hydroxide; D008276:Magnesium Hydroxide