title: Biosorption of Lead(II) by Arthrobacter sp. 25: Process Optimization and Mechanism.
abstract: In the present work, Arthrobacter sp. 25, a lead-tolerant bacterium, was assayed to remove lead(II) from aqueous solution. The biosorption process was optimized by response surface methodology (RSM) based on the Box-Behnken design. The relationships between dependent and independent variables were quantitatively determined by second-order polynomial equation and 3D response surface plots. The biosorption mechanism was explored by characterization of the biosorbent before and after biosorption using atomic force microscopy (AFM), scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The results showed that the maximum adsorption capacity of 9.6 mg/g was obtained at the initial lead ion concentration of 108.79 mg/l, pH value of 5.75, and biosorbent dosage of 9.9 g/l (fresh weight), which was close to the theoretically expected value of 9.88 mg/g. Arthrobacter sp. 25 is an ellipsoidalshaped bacterium covered with extracellular polymeric substances. The biosorption mechanism involved physical adsorption and microprecipitation as well as ion exchange, and functional groups such as phosphoryl, hydroxyl, amino, amide, carbonyl, and phosphate groups played vital roles in adsorption. The results indicate that Arthrobacter sp. 25 may be potentially used as a biosorbent for low-concentration lead(II) removal from wastewater.
authors.affiliation: College of Resource and Environment, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Jin
authors.affiliation: College of Resource and Environment, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: College of Resource and Environment, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Zang
authors.affiliation: College of Resource and Environment, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Hu
authors.affiliation: College of Resource and Environment, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Hu
authors.affiliation: College of Resource and Environment, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Ren
authors.affiliation: College of Resource and Environment, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Xiuhong
authors.initials: X
authors.lastname: Xu
authors.affiliation: College of Resource and Environment, Northeast Agricultural University, Harbin 150030, P.R. China.
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Qu
mesh_terms: D000327:Adsorption; D001173:Arthrobacter / Q000302:isolation & purification / Q000378:metabolism*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007854:Lead / Q000737:chemistry / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D012988:Soil Microbiology; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D062065:Wastewater / Q000382:microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D007477:Ions; D007854:Lead; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Arthrobacter sp.; biosorption mechanism; lead(II); optimization of biosorption process