Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 7-Day Trial for You or Your Team.

Learn More →

Plasma-based water treatment: development of a general mechanistic model to estimate the treatability of different types of contaminantsThis article b ...

Plasma-based water treatment: development of a general mechanistic model to estimate the... To determine the types of applications for which plasma-based water treatment (PWT) is best suited, the treatability of 23 environmental contaminants was assessed through treatment in a gas discharge reactor with argon bubbling, termed the enhanced-contact reactor. The contaminants were treated in a mixture to normalize reaction conditions and convective transport limitations. Treatability was compared in terms of the observed removal rate constant (kobs). To characterize the influence of interfacial processes on kobs, a model was developed that accurately predicts kobs for each compound, as well as the contributions to kobs from each of the three general degradation mechanisms thought to occur at or near the gas–liquid interface: ‘sub-surface’, ‘surface’ and ‘above-surface’. Sub-surface reactions occur just underneath the gas–liquid interface between the contaminants and dissolved plasma-generated radicals, contributing significantly to the removal of compounds that lack surfactant-like properties and so are not highly concentrated at the interface. Surface reactions occur at the interface between the contaminants and dissolved radicals, contributing significantly to the removal of surfactant-like compounds that have high interfacial concentrations. The contaminants’ interfacial concentrations were calculated using surface-activity parameters determined through surface tension measurements. Above-surface reactions are proposed to take place in the plasma interior between highly energetic plasma species and exposed portions of compounds that extend out of the interface. This mechanism largely accounts for the degradation of surfactant-like contaminants that contain highly hydrophobic perfluorocarbon groups, which are most likely to protrude from the interface. For a few compounds, the degree of exposure to the plasma interior was supported by new and previously reported molecular dynamics simulations results. By reviewing the predicted contributions from the three general mechanisms, it was determined that surface concentration is the dominant factor determining a compound’s treatability. These insights indicate that PWT would be most viable for the treatment of surfactant-like contaminants. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Physics D: Applied Physics IOP Publishing

Plasma-based water treatment: development of a general mechanistic model to estimate the treatability of different types of contaminantsThis article b ...

Download PDF
13 pages

Loading next page...
 
/lp/iop-publishing/plasma-based-water-treatment-development-of-a-general-mechanistic-SotOrWEw0h

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Copyright
Copyright © 2016 IOP Publishing Ltd
ISSN
0022-3727
eISSN
1361-6463
DOI
10.1088/1361-6463/50/1/014003
Publisher site
See Article on Publisher Site

Abstract

To determine the types of applications for which plasma-based water treatment (PWT) is best suited, the treatability of 23 environmental contaminants was assessed through treatment in a gas discharge reactor with argon bubbling, termed the enhanced-contact reactor. The contaminants were treated in a mixture to normalize reaction conditions and convective transport limitations. Treatability was compared in terms of the observed removal rate constant (kobs). To characterize the influence of interfacial processes on kobs, a model was developed that accurately predicts kobs for each compound, as well as the contributions to kobs from each of the three general degradation mechanisms thought to occur at or near the gas–liquid interface: ‘sub-surface’, ‘surface’ and ‘above-surface’. Sub-surface reactions occur just underneath the gas–liquid interface between the contaminants and dissolved plasma-generated radicals, contributing significantly to the removal of compounds that lack surfactant-like properties and so are not highly concentrated at the interface. Surface reactions occur at the interface between the contaminants and dissolved radicals, contributing significantly to the removal of surfactant-like compounds that have high interfacial concentrations. The contaminants’ interfacial concentrations were calculated using surface-activity parameters determined through surface tension measurements. Above-surface reactions are proposed to take place in the plasma interior between highly energetic plasma species and exposed portions of compounds that extend out of the interface. This mechanism largely accounts for the degradation of surfactant-like contaminants that contain highly hydrophobic perfluorocarbon groups, which are most likely to protrude from the interface. For a few compounds, the degree of exposure to the plasma interior was supported by new and previously reported molecular dynamics simulations results. By reviewing the predicted contributions from the three general mechanisms, it was determined that surface concentration is the dominant factor determining a compound’s treatability. These insights indicate that PWT would be most viable for the treatment of surfactant-like contaminants.

Journal

Journal of Physics D: Applied Physics – IOP Publishing

Published: Jan 11, 2017

There are no references for this article.