title: Investigation of equilibrium and kinetics of Cr(VI) adsorption by dried Bacillus cereus using response surface methodology.
abstract: In this study, response surface methodology (RSM) based on three-variable-five-level central composite rotatable design was used to analyze the effects of combined and individual operating parameters (biomass dose, initial concentration of Cr(VI) and pH) on the Cr(VI) adsorption capacity of dried Bacillus cereus. A quadratic polynomial equation was obtained to predict the adsorbed Cr(VI) amount. Analysis of variance showed that the effect of biomass dose was the key factor in the removal of Cr(VI). The maximum adsorbed Cr(VI) amount (30.93 mg g(-1)) was found at 165.30 mg L(-1), 2.96, and 3.01 g L(-1) for initial Cr(VI) concentration, pH, and biosorbent dosage, respectively. The surface chemical functional groups and microstructure of unloaded and Cr(VI)-loaded dried Bacillus cereus were identified by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Besides, the results gained from these studies indicated that Langmuir isotherm and the second-order rate expression were suitable for the removal of Cr(VI) from wastewater. The results revealed RSM was an effective method for optimizing biosorption process, and dried Bacillus cereus had a remarkable performance on the removal of Cr(VI) from wastewater.
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail: yk220220@126.com.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail: yk220220@126.com.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail: yk220220@126.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.affiliation: School of Civil Engineering, Wuhan University, Wuhan 430072, China E-mail: yk220220@126.com.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D001409:Bacillus cereus / Q000378:metabolism*; D018533:Biomass; D002857:Chromium / Q000378:metabolism*; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*; D062065:Wastewater / Q000032:analysis
chemical_list: D002857:Chromium; D062065:Wastewater; C074702:chromium hexavalent ion