Tolerance and removal of chromium（Ⅵ） by Bacillus sp. strain YB-1 isolated from electroplating sludge

• Published in: Transactions of Nonferrous Metals Society of China Vol. 18; no. 2; pp. 480 - 487
• Main Author: 刘云国 冯宝莹 樊霆 周海舟 李欣
• Format: Journal Article
• Language: English
• Published: 2008
• Subjects: 电镀技术
• ISSN: 1003-6326

Four chromium（Ⅵ）-resistant bacteria named YB-1, YB-2, YB-3 and YB-4 were isolated from Cr-electroplating sludge. YB-1 and YB-2 were identified as a member of Bacillus sp. based on morphology and Biolog Microstation System. The strain of YB-1 was selected to test for its resistance and ability to remove Cr（Ⅵ） from aqueous solution. The results indicate that YB-1 exhibits high MIC value which can almost reach 140 mg/L and the growth of YB-1 in liquid medium containing 60 mg/L Cr（Ⅵ） is affected especially in the late exponential phase and stationary phase. Furthermore, the potential of living and freeze-dried YB-1 biomass to remove Cr（Ⅵ） was studied in different pH, biosorbent dose, contact time and initial concentration using the batch method. At the optimal conditions, living and freeze-dried biomass are capable of absorbing 34.5 mg/g and 17.8 mg/g chromium（Ⅵ） at initial concentration of 60 mg/L, respectively. The adsorption data were fitted to Langmuir isotherm model for these two sorbents. Kinetic studies show that the rates of sorption all follow the pseudo-second order kinetics.