title: Chromium (VI) detoxification by oxidation and flocculation of exopolysaccharides from Arthrobacter sp. B4.
abstract: The exopolysaccharides from Arthrobacter sp. B4 (B4-EPS) exhibited an excellent chromium (VI) (Cr(VI)) removal capability without any pH adjustment, whereby 50mgL(-1) of Cr(VI) could be completely removed by 4gL(-1) of B4-EPS. The kinetics tests revealed that the first-order rate constant was 8.3×10(-5)s(-1) and the optimal reaction time was 720min. However, a low initial concentration of Cr(VI) (5-30mgL(-1)) would accelerate the reaction rate of Cr(VI) removal and shorten reaction time to less than 360min. Meanwhile, the X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible (UV-vis) spectra indicated that Cr(VI) was reduced to Cr(III) by B4-EPS in accordance with the emergence of the green reaction products. Furthermore, the Fourier transform-infrared spectra (FT-IR) and nuclear magnetic resonance (NMR) showed that carboxyl and hydroxyl groups of B4-EPS contributed to Cr(VI) reduction. Additionally, a feasible scheme for Cr(VI) detoxification by oxidation and flocculation of B4-EPS is presented.
authors.affiliation: School of Biological Science and Biotechnology, University of Jinan, 250022 Jinan, PR China. Electronic address: mls_liym@ujn.edu.cn.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Biological Science and Biotechnology, University of Jinan, 250022 Jinan, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: School of Biological Science and Biotechnology, University of Jinan, 250022 Jinan, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Fengying
authors.affiliation: School of Biological Science and Biotechnology, University of Jinan, 250022 Jinan, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Bao
authors.affiliation: School of Biological Science and Biotechnology, University of Jinan, 250022 Jinan, PR China.
authors.forename: Zhiheng
authors.initials: Z
authors.lastname: Hu
authors.affiliation: School of Biological Science and Biotechnology, University of Jinan, 250022 Jinan, PR China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Zhu
authors.affiliation: School of Biological Science and Biotechnology, University of Jinan, 250022 Jinan, PR China.
authors.forename: Yueyue
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: School of Biological Science and Biotechnology, University of Jinan, 250022 Jinan, PR China.
authors.forename: Zhaodang
authors.initials: Z
authors.lastname: Lin
authors.affiliation: School of Biological Science and Biotechnology, University of Jinan, 250022 Jinan, PR China.
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Dong
mesh_terms: D001173:Arthrobacter / Q000737:chemistry* / Q000378:metabolism*; D002857:Chromium / Q000378:metabolism*; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D008658:Inactivation, Metabolic; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D011135:Polysaccharides, Bacterial; D002857:Chromium
keywords: Chromium (VI); Detoxification; Exopolysaccharides