title: Removal of lead ions by acid activated and manganese oxide-coated bentonite.
abstract: This paper presents the adsorption of Pb(II) from aqua solutions onto Unye (Turkey) bentonite in raw (RB), acid activated (AAB) and manganese oxide-coated (MCB) forms. Adsorption of Pb(II) by RB, AAB and MCB sample was investigated as a function of the initial Pb(II) concentration, solution pH, ionic strength, temperature and inorganic ligand (Cl(-)). Changes in the surfaces and structure were characterized by means of XRD, IR and potentiometric titration. The Langmuir monolayer adsorption capacities of RB, AAB and MCB in 0.1M KNO(3) solution were estimated as 16.70, 8.92 and 58.88 mg/g, respectively. The spontaneity of the adsorption process is established by decrease in DeltaG which varied from -21.60 to -28.60 kJ/mol (RB), -22.63 to -29.98 kJ/mol (AAB) and -19.57 to -26.22 (MCB) in temperature range 303-338 K.
authors.affiliation: Ahi Evran University, Faculty of Arts and Science, Department of Chemistry, 40100 Kirsehir, Turkey. erdalern@omu.edu.tr
authors.forename: E
authors.initials: E
authors.lastname: Eren
authors.forename: B
authors.initials: B
authors.lastname: Afsin
authors.forename: Y
authors.initials: Y
authors.lastname: Onal
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007854:Lead / Q000737:chemistry / Q000302:isolation & purification*; D008024:Ligands; D017895:Manganese Compounds / Q000737:chemistry*; D015233:Models, Statistical; D009566:Nitrates / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D017680:Potassium Compounds / Q000737:chemistry; D011199:Potentiometry; D013055:Spectrophotometry, Infrared / Q000379:methods; D013696:Temperature; D013816:Thermodynamics; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D007477:Ions; D008024:Ligands; D017895:Manganese Compounds; D009566:Nitrates; D010087:Oxides; D017680:Potassium Compounds; D001546:Bentonite; D007854:Lead; C027424:manganese oxide; C023844:potassium nitrate