Fabrication of porous and interconnected PBI/P84 ultrafiltration membranes using [EMIM]OAc as the green solvent

2013 ◽  
Vol 87 ◽  
pp. 194-203 ◽  
Author(s):  
Ding Yu Xing ◽  
Sui Yung Chan ◽  
Tai-Shung Chung
Keyword(s):  
Green Solvent ◽  
Ultrafiltration Membranes

Arene Dearomatization via Radical Hydroarylation

2019 ◽  
Author(s):  
Autumn Flynn ◽  
Kelly McDaniel ◽  
Meredith Hughes ◽  
David Vogt ◽  
Nathan Jui
Keyword(s):  
Precious Metal ◽  
Room Temperature ◽  
Aryl Halide ◽  
Solvent System ◽  
Benzene Derivatives ◽  
Green Solvent ◽  
Photocatalytic System

A photocatalytic system for the dearomative hydroarylation of benzene derivatives has been developed. Using a combination of an organic photoredox catalyst and an amine reductant, this process operates through a reductive radical-polar crossover mechanism where aryl halide reduction triggers a regioselective cyclization event, giving rise to a range of complex spirocyclic cyclohexadienes. This light-driven protocol functions at room temperature in a green solvent system (aq. MeCN), without the need for precious metal-based catalysts or reagents, or the generation of stoichiometric metal byproducts.

Monitoring and maintaining the integrity of immersed ultrafiltration membranes used for pathogen protection

2002 ◽  
Vol 2 (5-6) ◽  
pp. 307-311
Author(s):  
P. Côté ◽  
J. Cadera ◽  
N. Adams ◽  
G. Best
Keyword(s):  
Drinking Water ◽  
Membrane Filtration ◽  
Ultrafiltration Membranes ◽  
Vacuum Decay ◽  
Integrity Monitoring ◽  
Pressure Decay ◽  
Decay Test ◽  
Conventional Technology ◽  
Water Borne

Membrane filtration has become the preferred alternative to conventional technology to remove water-borne pathogens in the preparation of drinking water. This paper presents the integrity monitoring and maintenance options for the ZeeWeed® immersed membrane. Results from two versions of air-based tests, a pressure decay test and a vacuum decay test are presented and shown to be conservative when compared to challenge results from independent studies.

Predictability of fouling-potential of raw water for ultrafiltration membranes

2011 ◽  
Vol 11 (4) ◽  
pp. 481-489
Author(s):  
S. Krause ◽  
A. Obermayer
Keyword(s):  
Water Quality ◽  
Membrane Fouling ◽  
Large Scale ◽  
High Capacity ◽  
Raw Water ◽  
Ultrafiltration Membranes ◽  
Small Water ◽  
Lab Experiments ◽  
Flux Decline ◽  
Public Drinking Water

The public drinking water supply of southern Germany is characterized by a rather decentralized network. Due to the hydrogeological setting in these parts of Germany many of the small water works with an average capacity of 50 m3/h have to treat raw water extracted from karstic or cliffy aquifers. These raw waters tend to be contaminated with particles and pathogens acquired during snowmelt or after strong rainfalls. In the last decade ultrafiltration has become the technology of choice for the removal of the aforementioned contaminants. Flux decline caused by unanticipated membrane fouling is the main limitation for the application of ultrafiltration membranes. This paper describes how membrane fouling phenomena can be predicted by using a statistical approach based on data from large scale filtration systems in combination with field and lab experiments on raw water quality and membrane performance. The data defines water quality and respective fouling phenomena both in technical scale filtration plants and in lab experiments of eleven different raw waters. The method described here is more economically feasible for small water works when compared to typical pilot experiments that are used for high capacity water works.

Electrolysis of Ionic Liquids. A Possible Keystone for the Achievement of Green Solvent-Catalyst Systems

2013 ◽  
Vol 17 (3) ◽  
pp. 204-219 ◽  
Author(s):  
Marta Feroci ◽  
Isabella Chiarotto ◽  
Achille Inesi
Keyword(s):  
Ionic Liquids ◽  
Green Solvent ◽  
Catalyst Systems

Effect of the membrane potential on the performance of ultrafiltration membranes

1986 ◽  
Vol 51 (3) ◽  
pp. 539-544 ◽  
Author(s):  
Hans-Hartmut Schwarz ◽  
Vlastimil Kůdela ◽  
Jaromír Lukáš ◽  
Jiří Vacík ◽  
Volker Gröbe
Keyword(s):  
Membrane Potential ◽  
Concentration Polarization ◽  
Ultrafiltration Membranes ◽  
Membrane Cleaning ◽  
Gel Layer ◽  
Charged Membrane ◽  
Protein Molecules ◽  
Polysulfone Membranes ◽  
Pressure Driven

In the pressure driven process the performance of membranes for ultrafiltration can be changed by incorporating charged groups into the membranes. sulfonation of polysulfone membranes the membrane potential is varied. On interaction of the negatively charged membrane with positively or negatively charged protein molecules the formation of a concentration polarization gel layer proceeds at different rate. Thus, the performance of the membrane can be controlled by the membrane potential. The dependence of the performance on the potential is discussed and procedures for membrane cleaning are suggested.

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