title: Biosorption of Fe(II) and Mn(II) ions from aqueous solution by rice husk ash.
abstract: Rice husk ash (RHA), an agricultural waste, was used as biosorbent for the removal of Iron(II) and Manganese(II) ions from aqueous solutions. The structural and morphological characteristics of RHA and its elemental compositions before and after adsorption of Fe(II) and Mn(II) were determined by scanning electron microscopic (SEM) and X-ray fluorescence (XRF) analyses. Batch experiments were carried out to determine the influence of initial pH, contact time, adsorbent dosage, and initial concentration on the removal of Fe(II) and Mn(II) ions. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) models were applied to describe the biosorption isotherm of the metal ions by RHA. The correlation coefficient (R (2)) of Langmuir and Freundlich isotherm models equals 0.995 and 0.901 for Fe(II), 0.9862 and 0.8924 for Mn(II), respectively, so the Langmuir model fitted the equilibrium data better than the Freundlich isotherm model. The mean free energy values evaluated from the D-R model indicated that the biosorption of Fe(II) and Mn(II) onto RHA was physical in nature. Experimental data also showed that the biosorption processes of both metal ions complied with the pseudo-second-order kinetics.
authors: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors: Ying
authors: 0000-0003-4196-161X
authors: Y
authors: Zhang
authors: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors: Jiaying
authors: J
authors: Zhao
authors: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors: Zhao
authors: Z
authors: Jiang
authors: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors: Dexin
authors: D
authors: Shan
authors: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors: Yan
authors: Y
authors: Lu
mesh_terms: D000327:Adsorption; D001673:Biodegradation, Environmental; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007501:Iron / Q000302:isolation & purification*; D007700:Kinetics; D008345:Manganese / Q000302:isolation & purification*; D012275:Oryza / Q000737:chemistry* / Q000648:ultrastructure; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D013696:Temperature; D013997:Time Factors; D014866:Waste Products
chemical_list: D007477:Ions; D012996:Solutions; D014866:Waste Products; D008345:Manganese; D007501:Iron