title: Effects of inorganic electrolyte anions on enrichment of Cu(II) ions with aminated Fe3O4/graphene oxide: Cu(II) speciation prediction and surface charge measurement.
abstract: The present work evaluated the effects of six inorganic electrolyte anions on Cu(II) removal using aminated Fe3O4/graphene oxide (AMGO) in single- and multi-ion systems. A 2(6-2) fractional factorial design (FFD) was employed for assessing the effects of multiple anions on the adsorption process. The results indicated that the Cu(II) adsorption was strongly dependent on pH and could be significantly affected by inorganic electrolyte anions due to the changes in Cu(II) speciation and surface charge of AMGO. In the single-ion systems, the presence of monovalent anions (Cl(-), ClO4(-), and NO3(-)) slightly increased the Cu(II) adsorption onto AMGO at low pH, while the Cu(II) adsorption was largely enhanced by the presence of SO4(2-), CO3(2-), and HPO4(2-). Based on the estimates of major effects and interactions from FFD, the factorial effects of the six selected species on Cu(II) adsorption in multi-ion system were in the following sequence: HPO4(2-)>CO3(2-)>Cl(-)>SO4(2-)>NO3(-)=ClO4(-), and the combined factors of AD (Cl(-)×SO4(2-)) and EF (Cl(-)×SO4(2-)) had significant effects on Cu(II) removal.
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Xin-jiang
authors: XJ
authors: Hu
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China. Electronic address: hnuese@126.com.
authors: Yun-guo
authors: YG
authors: Liu
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Guang-ming
authors: GM
authors: Zeng
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Hui
authors: H
authors: Wang
authors: College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541004, PR China.
authors: Shao-hong
authors: SH
authors: You
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Xi
authors: X
authors: Hu
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Xiao-fei
authors: XF
authors: Tan
authors: College of Resources and Environment, Hunan Agricultural University, Changsha 410128, PR China.
authors: An-wei
authors: AW
authors: Chen
authors: College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
authors: Fang-ying
authors: FY
authors: Guo
mesh_terms: D000327:Adsorption; D000838:Anions / Q000737:chemistry*; D002413:Cations, Divalent; D003300:Copper / Q000737:chemistry*; D004573:Electrolytes; D005290:Ferric Compounds / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010087:Oxides
chemical_list: D000838:Anions; D002413:Cations, Divalent; D004573:Electrolytes; D005290:Ferric Compounds; D010087:Oxides; C000499:ferric oxide; D006108:Graphite; D003300:Copper
keywords: Adsorption; Cu(II) speciation prediction; Fractional factorial design; Graphene oxide; Inorganic electrolyte anions; Zeta potential