文献类型：期刊文献

英文题名：Effect of fluid shear stress on catalytic activity of biopalladium nanoparticles produced by Klebsiella pneumoniae ECU-15 on Cr(VI) reduction reaction

作者：Lei, Bin[1]; Zhang, Xu[1]; Zhu, Minglong[1]; Tan, Wensong[1]

机构：[1] State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China

年份：2014

卷号：1

期号：1

外文期刊名：Bioresources and Bioprocessing

收录：EI(收录号：20224513078559)

语种：英文

外文关键词：Bacteria - Cell membranes - Chromium compounds - Diffusion in liquids - Nanoparticles - Palladium compounds - Reaction rates - Shear flow - Shear stress - Synthesis (chemical)

摘要：Background: Biopalladium (bioPd(0)) nanoparticles on Klebsiella Pneumoniae ECU-15 were synthesized mainly on the microorganism's surface. Data suggest that the resistance of mass transfer around the cell surface region plays a critical role in bioPd(0) synthesis process. However, the mechanisms for its role remains elusive. Results: The experimental results indicated that 1) diffusion resistance existed around the microorganism's cell in reaction vessel and 2) fluid shear stress affected the mass transfer rates differently according to its strength and thus had varying effects on the bioPd(0) synthesis. More than 97.9 ± 1.5% Chromium(VI)(Cr(VI)) (384 μM) was reduced to Cr(III) within 20 min with 5% Pd/bioPd(0) as catalyst, which was generated by the K. Pneumoniae ECU-15, and the catalytic performance of Pd/bioPd(0) was stable over 6 months. The optimal condition of bioreduction of Pd(II) to Pd(0) was determined at the Kolmogorov eddy length of 7.33 ± 0.5 μm and lasted for 1 h in the extended reduction process after the usual adsorption and reduction process. Conclusions: It is concluded that a high bioPd(0) catalytic activity can be achieved by controlling the fluid shear stress intensity in an extended reduction process in the bioreactor. ? 2014 Lei et al.