Bilateral photocatalytic mechanism of dye degradation by a designed ferrocene-functionalized cluster under natural sunlight

2020 ◽  
Vol 10 (3) ◽  
pp. 757-767 ◽  
Author(s):  
Kuan-Guan Liu ◽  
Farzaneh Rouhani ◽  
Xue-Mei Gao ◽  
Mahsa Abbasi-Azad ◽  
Jing-Zhe Li ◽  
...  

Extensive composition engineering research has been conducted on bandgap tunability, but the combination of two mechanisms for better photon harvesting over a wide range has rarely happened; this is of great importance for improving photocatalytic efficiency with sunlight.

2022 ◽  
Vol 275 ◽  
pp. 125304
Author(s):  
Marie Le Pivert ◽  
Hongri Suo ◽  
Gang Tang ◽  
Han Qiao ◽  
Zhicheng Zhao ◽  
...  

Author(s):  
Kyle Bethel ◽  
Steven C. Catha ◽  
Melvin F. Kanninen ◽  
Randall B. Stonesifer ◽  
Ken Charbonneau ◽  
...  

The research described in this paper centers on a composite of thermoplastic materials that can be inserted in a degraded steel pipe to completely restore its strength. Through the use of fabrics consisting of ultra high strength fibers that are co-helically wrapped over a thin walled thermoplastic cylindrical tube that serves as a core, arbitrarily high pressures can be achieved. This paper first outlines the design, manufacturing and installation procedures developed for this unique material to provide a context for the engineering research. Based on this outline, the technological basis that has been developed for assuring the strength and long term durability of this concept during its insertion, and in its very long term service as a liner in energy transmission pipelines, is presented in detail. The research that is described includes burst testing of the material in stand alone pipe form, load/elongation testing of ultra high strength fabrics, and linear and nonlinear elastic and viscoelastic analysis models. This body of work indicates that the concept is fundamentally feasible for restoring a wide range of large diameter natural gas and liquid transmission pipelines to be able to carry arbitrarily high pressures over very long lifetimes. It also indicates that liners can be safely installed in long lengths even in lines with severe bends in a continuous manner. With further research the concept has the potential for eliminating hydro testing and smart pigging during service, and could possibly be installed in some lines that are currently unpiggable.


Microbiology ◽  
2021 ◽  
Vol 167 (12) ◽  
Author(s):  
Feixue Liu ◽  
Dinesh Singh Shah ◽  
Laszlo Csetenyi ◽  
Geoffrey Michael Gadd

Biomineralization is a ubiquitous process in organisms to produce biominerals, and a wide range of metallic nanoscale minerals can be produced as a consequence of the interactions of micro-organisms with metals and minerals. Copper-bearing nanoparticles produced by biomineralization mechanisms have a variety of applications due to their remarkable catalytic efficiency, antibacterial properties and low production cost. In this study, we demonstrate the biotechnological potential of copper carbonate nanoparticles (CuNPs) synthesized using a carbonate-enriched biomass-free ureolytic fungal spent culture supernatant. The efficiency of the CuNPs in pollutant remediation was investigated using a dye (methyl red) and a toxic metal oxyanion, chromate Cr(VI). The biogenic CuNPs exhibited excellent catalytic properties in a Fenton-like reaction to degrade methyl red, and efficiently removed Cr(VI) from solution due to both adsorption and reduction of Cr(VI). X-ray photoelectron spectroscopy (XPS) identified the oxidation of reducing Cu species of the CuNPs during the reaction with Cr(VI). This work shows that urease-positive fungi can play an important role not only in the biorecovery of metals through the production of insoluble nanoscale carbonates, but also provides novel and simple strategies for the preparation of sustainable nanomineral products with catalytic properties applicable to the bioremediation of organic and metallic pollutants, solely and in mixtures.


Author(s):  
Veena Gayathri Krishnaswamy

The limited availability of fresh water is a global crisis. The growing consumption of fresh water due to anthropogenic activities has taken its toll on available water resources. Unfortunately, water bodies are still used as sinks for waste water from domestic and industrial sources. Azo dyes account for the majority of all dye stuffs, produced because they are extensively used in the textile, paper, food, leather, cosmetics, and pharmaceutical industries. Bacterial degradation of azo dyes under certain environmental conditions has gained momentum as a method of treatment, as these are inexpensive, eco-friendly, and can be applied to wide range of such complex dyes. The enzymatic approach has attracted much interest with regard to degradation of azo dyes from wastewater. The oxido-reductive enzymes are responsible for generating highly reactive free radicals that undergo complex series of spontaneous cleavage reactions, due to the susceptibility of enzymes to inactivation in the presence of the other chemicals. The oxidoreductive enzymes, such as lignin peroxidase, laccases, tyrosinase, azoreductase, riboflavin reductive, polyphenol oxidase, and aminopyrine n-demethylase, have been mainly utilized in the bacterial degradation of azo dye. Along with the reductive enzymes, some investigators have demonstrated the involvement in some other enzymes, such as Lignin peroxides and other enzymes. This chapter reviews the importance of enzymes in dye degradation.


2018 ◽  
Vol 64 ◽  
pp. 131-148
Author(s):  
J. Brian Davies

Alex Cullen combined the sharpest of scientific minds with a gentle personality and a great sense of humour. He was Professor and Head of the Department of Electrical Engineering at Sheffield from 1955 to 1967, and then Head of the Department of Electrical Engineering at University College London (UCL) until 1980. He continued his research there as a Science and Engineering Research Council Senior Fellow until 1985, and for some years as Research Fellow of UCL. His research concerned electromagnetic waves over a wide range of microwave devices and measurement techniques, the latter at a fundamental level. These contributions were of a highly innovative and ‘ground-breaking’ nature. He was appointed OBE in 1960, and elected Fellow of the Royal Society in 1977. He was an accomplished jazz musician, playing drums and clarinet. He was a signatory of a letter to The Times in January 1986, calling on Prime Minister Margaret Thatcher to ‘Save British Science’. This led to the foundation of the Save British Science pressure group, now the Campaign for Science and Engineering (CaSE), which has built up an enviable reputation with politicians and the media in representing the concerns of scientists and engineers. When (now Sir) Eric Ash left UCL in 1985 to become Rector of Imperial College, he remarked that Alex was ‘the last gentleman in the business’.


2019 ◽  
Vol 3 (3) ◽  
pp. 75 ◽  
Author(s):  
Mamo Gebrezgiabher ◽  
Gebrehiwot Gebreslassie ◽  
Tesfay Gebretsadik ◽  
Gebretinsae Yeabyo ◽  
Fikre Elemo ◽  
...  

Magnetically recyclable C-doped TiO2/Fe3O4 (C-TiO2/Fe3O4) nanocomposite was successfully synthesized via a sol–gel method. The synthesized samples were characterized using SEM, energy-dispersive X-ray spectroscopy (EDS), FTIR, and UV-VIS diffuse reflectance spectroscopy (DRS) techniques. The results clearly showed that a C-TiO2/Fe3O4 nanocomposite was produced. The photocatalytic activities of the prepared pristine (TiO2), C-doped TiO2 (C-TiO2) and C-TiO2/Fe3O4 were evaluated by the photodegradation of methyl orange (MO) under natural sunlight. The effect of catalyst loading and MO concentration were studied and optimized. The C-TiO2/Fe3O4 nanocomposite exhibited an excellent photocatalytic activity (99.68%) that was higher than the TiO2 (55.41%) and C-TiO2 (70%) photocatalysts within 150 min. The magnetic nanocomposite could be easily recovered from the treated solution by applying external magnetic field. The C-TiO2/Fe3O4 composite showed excellent photocatalytic performance for four consecutive photocatalytic reactions. Thus, this work could provide a simple method for the mass production of highly photoactive and stable C-TiO2/Fe3O4 photocatalyst for environmental remediation.


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