title: Characterization of H3PO4-treated rice husk adsorbent and adsorption of copper(II) from aqueous solution.
abstract: Rice husk, a surplus agricultural byproduct, was applied to the sorption of copper from aqueous solutions. Chemical modifications by treating rice husk with H3PO4 increased the sorption ability of rice husk for Cu(II). This work investigated the sorption characteristics for Cu(II) and examined the optimum conditions of the sorption processes. The elemental compositions of native rice husk and H3PO4-treated rice husk were determined by X-ray fluorescence (XRF) analysis. The scanning electron microscopic (SEM) analysis was carried out for structural and morphological characteristics of H3PO4-treated rice husk. The surface functional groups (i.e., carbonyl, carboxyl, and hydroxyl) of adsorbent were examined by Fourier Transform Infrared Technique (FT-IR) and contributed to the adsorption for Cu(II). Adsorption isotherm experiments were carried out at room temperature and the data obtained from batch studies fitted well with the Langmuir and Freundlich models with R (2) of 0.999 and 0.9303, respectively. The maximum sorption amount was 17.0358 mg/g at a dosage of 2 g/L after 180 min. The results showed that optimum pH was attained at pH 4.0. The equilibrium data was well represented by the pseudo-second-order kinetics. The percentage removal for Cu(II) approached equilibrium at 180 min with 88.9% removal.
authors.affiliation: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China ; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Ying
authors.identifier: 0000-0003-4196-161X
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors.forename: Ru
authors.initials: R
authors.lastname: Zheng
authors.affiliation: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors.forename: Jiaying
authors.initials: J
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Ma
authors.affiliation: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Resource and Environment, Northeast Agricultural University, Harbin 150030, China.
authors.forename: Qingjuan
authors.initials: Q
authors.lastname: Meng
mesh_terms: D000327:Adsorption; D003300:Copper / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D012275:Oryza / Q000187:drug effects* / Q000648:ultrastructure; D010756:Phosphoric Acids / Q000494:pharmacology*; D012996:Solutions; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013997:Time Factors; D014866:Waste Products; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D010756:Phosphoric Acids; D012996:Solutions; D014866:Waste Products; D014874:Water Pollutants, Chemical; D003300:Copper; C030242:phosphoric acid