一分快三_一分快三平台_首页

Adsorption Removal of Multiple Dyes Using Biogenic Selenium Nanoparticles from an Escherichia coli Strain Overexpressed Selenite Reductase CsrF

Xian Xia, Zijie Zhou, Shijuan Wu, Dan Wang, Shixue Zheng and Gejiao Wang *

Abstract: Selenite reductase CsrF overexpressed Escherichia coli was used as a microbial factory
to produce Se(0) nanoparticles (Bio-SeNPs). The Bio-SeNPs were characterized by transmission
electronic microscopy, element mapping, scanning electron microscopy, energy-dispersive X-ray
spectrographs, Zeta-potential, dynamic light scattering, Fourier transform infrared spectroscopy and
X-ray photoelectron spectroscopy analyses. The results indicated that Bio-SeNPs are irregular spheres
with diameters from 60 to105 nm and mainly consist of Se(0), proteins and lipids. Furthermore,
it exhibited maximum adsorption capacity for anionic dye (congo red) at acidic pH and cationic dyes
(safranine T and methylene blue) at alkaline pH. To gain more insight, adsorption kinetics, adsorption
isotherms and adsorption thermodynamics studies were carried out. These results showed that
the adsorption capacities of congo red, safranine T and methylene blue were 1577.7, 1911.0 and
1792.2 mg/g, respectively. These adsorption processes were spontaneous and primarily physical
reactions. In addition, Bio-SeNPs can be effectively reused by 200 mmol/L NaCl. To the best of
our knowledge, this is the first report of adsorption removal dyes by Bio-SeNPs. The adsorption
capacities of Bio-SeNPs for congo red, safranine T and methylene blue were 6.8%, 25.2% and 49.0%
higher than that for traditional bio-based materials, respectively.



Designed By Alex