scholarly journals Fluorescent component and complexation mechanism of extracellular polymeric substances during dye wastewater biotreatment by anaerobic granular sludge

2018 ◽  
Vol 5 (2) ◽  
pp. 171445
Author(s):  
Na Li ◽  
Dong Wei ◽  
Qunqun Sun ◽  
Xiao Han ◽  
Bin Du ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Extracellular Polymeric Substances ◽  
Three Dimensional ◽  
Granular Sludge ◽  
Synchronous Fluorescence ◽  
Anaerobic Granular Sludge ◽  
Synchronous Fluorescence Spectra ◽  
Pseudo Second Order ◽  
The Difference ◽  
Complexation Mechanism

In this study, methylene blue (MB) wastewater was biotreated by anaerobic granular sludge (AnGS), and the fluorescent components of extracellular polymeric substances (EPS) and complexation mechanism were evaluated. Based on the experimental data, the sorption of MB by both live and inactivated AnGS followed the pseudo-second-order model, and the adsorption isotherm conformed well to the Langmuir model. It was shown that the difference in the sorption of live and inactivated AnGS was not significant, indicating that the sorption is mainly a physical–chemical process and metabolically mediated diffusion is negligible. The interaction between EPS and MB was proved by three-dimensional excitation–emission matrix (3D-EEM) and synchronous fluorescence spectra. 3D-EEM indicated that protein (PN)-like substances were the main peaks of EPS, and gradually quenched with increase of MB concentrations. According to synchronous fluorescence spectra, the main fluorescence quenching was caused by PN-like and humic-like fractions, and belonged to the static type of quenching. FTIR spectra demonstrated that hydroxyl and amino groups played a major role in MB sorption.

scholarly journals Behavior and Mechanism of Cesium Biosorption from Aqueous Solution by Living Synechococcus PCC7002

2020 ◽  
Vol 8 (4) ◽  
pp. 491 ◽  
Author(s):  
Runlan Yu ◽  
Hongsheng Chai ◽  
Zhaojing Yu ◽  
Xueling Wu ◽  
Yuandong Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Extracellular Polymeric Substances ◽  
Three Dimensional ◽  
Vital Role ◽  
Extracellular Proteins ◽  
Biosorption Mechanism ◽  
Transmission Electron ◽  
Passive Adsorption ◽  
Pseudo Second Order ◽  
Cs Ions

Many efforts have focused on the adsorption of metals from contaminated water by microbes. Synechococcus PCC7002, a major marine cyanobacteria, is widely applied to remove metals from the ocean’s photic zone. However, its ability to adsorb cesium (Cs) nuclides has received little attention. In this study, the biosorption behavior of Cs(I) from ultrapure distilled water by living Synechococcus PCC7002 was investigated based on kinetic and isotherm studies, and the biosorption mechanism was characterized by Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectrometry, and three-dimensional excitation emission matrix fluorescence spectroscopy. Synechococcus PCC7002 showed extremely high tolerance to Cs ions and its minimal inhibitory concentration was 8.6 g/L. Extracellular polymeric substances (EPS) in Synechococcus PCC7002 played a vital role in this tolerance. The biosorption of Cs by Synechococcus PCC7002 conformed to a Freundlich-type isotherm model and pseudo-second-order kinetics. The binding of Cs(I) was primarily attributed to the extracellular proteins in EPS, with the amino, hydroxyl, and phosphate groups on the cell walls contributing to Cs adsorption. The biosorption of Cs involved two mechanisms: Passive adsorption on the cell surface at low Cs concentrations and active intracellular adsorption at high Cs concentrations. The results demonstrate that the behavior and mechanism of Cs adsorption by Synechococcus PCC7002 differ based on the Cs ions concentration.

The synchronous fluorescence spectra character of hypocrellin B with type I collagen under irradiation

2014 ◽  
Author(s):  
Jucheng Zhang ◽  
Heping Yan ◽  
Mengting Yang ◽  
Yongzhen Feng ◽  
Yun Huang ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Type I Collagen ◽  
Synchronous Fluorescence ◽  
Type I ◽  
Synchronous Fluorescence Spectra ◽  
Hypocrellin B

scholarly journals Synchronous fluorescence spectra of water contaminated by dispersed crude oil

2020 ◽  
Vol 50 (1) ◽  
Author(s):  
Emilia Baszanowska ◽  
Zbigniew Otremba
Keyword(s):  
Crude Oil ◽  
Fluorescence Spectra ◽  
Oil Pollution ◽  
Synchronous Fluorescence ◽  
Mining Equipment ◽  
Oil Emulsion ◽  
Synchronous Fluorescence Spectra ◽  
Emulsion Concentration ◽  
Petroleum Extraction

The development of petroleum extraction and transport technology does not ensure complete isolation of these substances from the natural environment. This problem is exacerbated by the location of mining equipment on the sea shelf and the fact that numerous submarine pipelines, tankers and handling terminals can also emit oil pollution. Therefore, the possibility of detecting oil dispersed in the water is particularly important. This paper reports the efforts to identify methods of characterization of the water containing the crude oil emulsion in a very low concentration (a few to several tens of ppm). Due to this, the effect of emulsion concentration on the possibility of its objective characterization using synchronous fluorescence spectra was studied. The similarity of spectra at various oil concentrations was analysed. It has been shown that the stabilization of the shape of synchronous fluorescence spectra occurs at relatively low oil concentrations.

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