title: Removal of Hg(II) from aqueous solution using sodium humate as heavy metal capturing agent.
abstract: An environmental friendly and economic natural biopolymer-sodium humate (HA-Na) was used to capture Hg(II) from aqueous solutions, and the trapped Hg(II) (HA-Na-Hg) was then removed by aluminium coagulation. The best Hg(II) capturing performance (90.60%) was observed under the following conditions: initial pH of 7.0, coagulation pH of 6.0, HA-Na dosage of 5.0 g L-1, Al2(SO4)3.18H2O dosage of 4.0 g L-1, initial Hg(II) concentration of 50 mg L-1and capturing time of 30 min. The HA-Na compositions with the molecular weight beyond 70 kDa showed the most intense affinity toward Hg(II). The results showed that the reaction equilibrium was achieved within 10 min (pH 7.0), and could be well fitted by the pseudo-second-order kinetics model. The capturing process could be well described by the Langmuir isotherm model and the maximum capturing capacity of Hg(II) was high up to 9.80 mg g-1at 298 K (pH 7.0). The Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis showed that the redox reaction between Hg(II) and HA-Na and the coordination reaction of carboxyl and hydroxy groups of HA-Na with Hg(II) were responsible for Hg(II) removal. The successive regeneration experiment showed that the capturing efficiency of humates for Hg(II) was maintained at about 51% after five capture-regeneration recycles.
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China E-mail: liuyongsicnu@sina.com.
authors.forename: Shixiang
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China E-mail: liuyongsicnu@sina.com; Key Laboratory of Treatment for Special Wastewater of Sichuan Province Higher Education System, Sichuan, Chengdu 610066, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China E-mail: liuyongsicnu@sina.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Fan
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China E-mail: liuyongsicnu@sina.com.
authors.forename: Anlan
authors.initials: A
authors.lastname: Zhou
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China E-mail: liuyongsicnu@sina.com.
authors.forename: Lu
authors.initials: L
authors.lastname: Fan
authors.affiliation: College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, China E-mail: liuyongsicnu@sina.com.
authors.forename: Yulan
authors.initials: Y
authors.lastname: Mu
mesh_terms: D000327:Adsorption; D000534:Alum Compounds / Q000737:chemistry; D000535:Aluminum; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008628:Mercury / Q000302:isolation & purification*; D019216:Metals, Heavy; D056951:Photoelectron Spectroscopy; D059027:Recycling; D012964:Sodium; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D000534:Alum Compounds; D006812:Humic Substances; D019216:Metals, Heavy; D012996:Solutions; D014874:Water Pollutants, Chemical; C041524:aluminum sulfate; D012964:Sodium; D000535:Aluminum; D008628:Mercury