title: Effects of background electrolytes and ionic strength on enrichment of Cd(II) ions with magnetic graphene oxide-supported sulfanilic acid.
abstract: To elucidate the influence mechanisms of background electrolytes and ionic strength on Cd(II) removal, the adsorption of Cd(II) onto magnetic graphene oxide-supported sulfanilic acid (MGO-SA) in aqueous solutions containing different types and concentrations of background electrolytes was studied. The results indicate that Cd(II) adsorption was strongly dependent on pH and could be strongly affected by background electrolytes and ionic strength. The Cd(II) removal was decreased with the presence of background electrolyte cations (Na(+), K(+), Ca(2+), Mg(2+), Mn(2+), Zn(2+), and Ni(2+)), and the divalent cations exerted more obvious influences on the Cd(II) uptake than the monovalent cations at pH 6. Both Cl(-) and NO3(-) had negative effects on Cd(II) adsorption because they can form water-soluble metal-anion complexes with Cd(II) ions. The presence of 0.01molL(-1) Na3PO4 reduced the removal percentage of Cd(II) at pH<5 but extremely enhanced the Cd(II) removal when the pH>5. The Cd(II) adsorption was sensitive to changes in the concentration of NaCl, NaNO3, NaClO4, and Na3PO4. Besides, the adsorption isotherm of Cd(II) onto MGO-SA could be well described by the Freundlich model and was also influenced by the type of background electrolyte ions and the ionic strength.
authors.affiliation: 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.forename: Xin-jiang
authors.initials: XJ
authors.lastname: Hu
authors.affiliation: 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.forename: Yun-guo
authors.initials: YG
authors.lastname: Liu
authors.affiliation: 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.forename: Guang-ming
authors.initials: GM
authors.lastname: Zeng
authors.affiliation: College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541004, PR China.
authors.forename: Shao-hong
authors.initials: SH
authors.lastname: You
authors.affiliation: 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.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: 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.forename: Xi
authors.initials: X
authors.lastname: Hu
authors.affiliation: 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.forename: Yi-ming
authors.initials: YM
authors.lastname: Guo
authors.affiliation: 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.forename: Xiao-fei
authors.initials: XF
authors.lastname: Tan
authors.affiliation: 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.forename: Fang-ying
authors.initials: FY
authors.lastname: Guo
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry* / Q000302:isolation & purification; D002413:Cations, Divalent; D004573:Electrolytes; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D060328:Magnetic Phenomena; D009994:Osmolar Concentration; D013425:Sulfanilic Acids / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D004573:Electrolytes; D013425:Sulfanilic Acids; D002104:Cadmium; D006108:Graphite
keywords: Adsorption; Background electrolyte; Cd(II) species; Effect; Ionic strength; Visual MINTEQ