title: Removal of basic dyes from aqueous solutions with a treated spent bleaching earth.
abstract: A spent bleaching earth from an edible oil refinery was treated by impregnation with a normal sodium hydroxide solution followed by mild thermal treatment (100 degrees C). The obtained material (TSBE) was washed, dried, and characterized by X-ray diffraction, FTIR, SEM, BET, and thermal analysis. The clay structure was not apparently affected by the treatment and the impregnated organic matter was quantitatively removed. We have investigated the comparative sorption of safranine and methylene blue on this material, the spent bleaching earth (SBE), and the virgin bleaching earth (VBE). The kinetic results fit the pseudo-second-order kinetic model and the Weber and Morris intraparticle diffusion model. The pH had no effect on the sorption efficiency. The sorption isotherms followed the Langmuir model for various sorbent concentrations with good values of the determination coefficient. A linear relationship was found between the calculated maximum removal capacity and the solid/solution ratio. A comparison between the results obtained with this material and those of the literature highlighted the low cost and the good removal capacity of treated spent bleaching earth.
authors.affiliation: Laboratoire de valorisation des matériaux, University of Mostaganem, B.P. 227, Mostaganem R.P., Algeria.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mana
authors.forename: Mohand-Said
authors.initials: MS
authors.lastname: Ouali
authors.forename: L C
authors.initials: LC
authors.lastname: de Menorval
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D000077215:Clay; D004396:Coloring Agents / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D008751:Methylene Blue / Q000302:isolation & purification; D008855:Microscopy, Electron, Scanning; D010619:Phenazines / Q000302:isolation & purification; D012972:Sodium Hydroxide / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013783:Textile Industry; D014867:Water / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D000538:Aluminum Silicates; D004396:Coloring Agents; D010619:Phenazines; D012996:Solutions; D014867:Water; D012972:Sodium Hydroxide; D000077215:Clay; D008751:Methylene Blue; C009195:safranine T