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

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.

The Use of Pre-Heated Black Cumin Seeds (<i>Nigella sativa</i>) for Sorption Basic Dyes from Aqueous Solutions

“…The comparison of the R 2 values pointed out that the adsorption values are more suitably fitted to the PSO than the PFO model. These results display how HBCS adsorption kinetics of the MB dye fit the pseudo-second-order model and the adsorption of the MB dye onto HBCS is controlled by chemisorptions [Xia et al, 2018]. The process of adsorption in the pseudo-second-order model consists of three stages: the first one is the membrane diffusion stage, followed by the stage of surface adsorption and finally, the internal diffusion process stage.…”

“…High pH values caused the surface of the adsorbent (HCBS) to become increasingly negatively charged and increases the dye attraction to the active sites of the surface of the adsorbent, explaining the increased removal efficiency of both dyes when pH is increased. The removal efficiency of both dyes with the increase in the solution pH showed a trend that is elucidated by the fact that decreasing pH caused the adsorbent (HBCS) surface to become more positively charged, therefore reducing the attraction of the dye to the active sites of the adsorbent surface [Xia et al, 2018]. The removal of the MB and ST dyes can be impacted by the zero point charge pH (pH zero ) of the adsorbent.…”

“…However, a distinguished difference could be noted on the adsorption capacities of MB (1.83 mg/g) and ST (2.2 mg/g) dyes. The difference in the ionic strength of dye molecules may be the cause of the higher removal capacity of the ST dye in comparison to the MB dye onto HBCS [Xia et al, 2018].…”

“…ST is a basic red dye substance (basic red 2(BR-2) with an IUPAC designation as 3, 7-Diamino -2, 8-dimethyl-5-phenyl phenazinium chlorate and is a cationic dye [Xia et al, 2018]. It is used in different areas such as chemistry, biology, and medicine.…”

Polypyrrole-Chitosan-CaFe2O4 Layer Sensor for Detection of Anionic and Cationic Dye Using Surface Plasmon Resonance

“…In the past two decades, many researchers have focused on removal and detection of dyes, such as MO and MB, from environmental areas and wastewater [1]. Many methods that are based on biological [5], chemical, and physical properties of materials [6] have been used to degrade MO and MB. The conventional methods including electrooxidation [7], electro-Fenton [8], adsorption [9], ozone [10], photocatalytic [11], and reverse osmosis [12].…”