Grantee Research Project Results
2016 Progress Report: Integration of Filtration and Advanced Oxidation: Development of a Membrane Liquid-Phase Plasma Reactor
EPA Grant Number: R835332Title: Integration of Filtration and Advanced Oxidation: Development of a Membrane Liquid-Phase Plasma Reactor
Investigators: Bellona, Christopher , Holsen, Thomas M. , Dickenson, Eric , Mededovic Thagard, Selma
Institution: Clarkson University , Southern Nevada Water Authority
EPA Project Officer: Packard, Benjamin H
Project Period: August 16, 2012 through August 15, 2016 (Extended to August 15, 2017)
Project Period Covered by this Report: August 16, 2015 through August 15,2016
Project Amount: $499,779
RFA: Research and Demonstration of Innovative Drinking Water Treatment Technologies in Small Systems (2011) RFA Text | Recipients Lists
Research Category: Drinking Water , Water
Objective:
Engineer, develop and demonstrate an integrated process comprised of membrane technology and electrical discharge plasma generated via a novel reticulated vitreous carbon (RVC) electrode material. The successful development of this process will result in a technology that is scalable, robust, requires minimal chemical input, has a small footprint, and achieves a finished water quality better than treatment systems that require multiple technologies.
Progress Summary:
- There are a number of factors that influence the effectiveness of plasma for the degradation of organic contaminants. By evaluating all of the factors that affect the kinetics of degradation, the research team has identified the main parameters that need to be optimized in order to improve the process.
- The major factors impacting the effectiveness of plasma in degrading organic contaminants include maximizing the contact between contaminants and plasma, utilizing the hydrogen peroxide produced by plasma, and adjusting the power supply parameters to increase plasma efficiency.
- Increasing the contact between plasma and contaminants was achieved by increasing the grounded electrode area, sparging the solution with argon, and passing the feed solution through the high voltage electrode.
- Producing plasma in the gas phase is much more effective than producing plasma in the liquid phase.
- Producing plasma with a multiple point electrode material is much more effective than with a single point high-voltage electrode.
- By optimizing the plasma reactor, contaminant degradation kinetics were increased by more than 20 times.
- Degradation experiments with a wide variety of organic contaminants demonstrated that plasma is an effective degradation process however, hydrophilic and non-surface active compounds were not always well removed. We theorize that compounds must interact with the plasma channel to be well degraded.
- The plasma process produces a significant amount of hydrogen peroxide. Fenton’s reaction can be initiated by adding ferrous iron or by using an iron-coated electrode, which significantly improves contaminant degradation for compounds that do not interact with the plasma channel.
- Plasma is very effective for the degradation of perfluorinated compounds particularly when using the team’s optimized reactor configuration. Results from various experiments indicate that the team’s optimized plasma reactor system is one of the most efficient treatment process for the destruction of perfluorinated compounds.
- Background matrices in perfluoroalkyl substances (PFAS) contaminated groundwater had minimal impact on degradation. The demonstration-scale plasma reactor proved to be significantly more efficient than the bench-scale system for PFAS degradation.
- Plasma is effective for surface active compound degradation and a model using surface excess and hydroxyl radical rate constants can predict plasma efficiency. We surmise that there are two main mechanisms by which plasma degrades organic contaminants. One degradation mechanism is through reactions in the bulk liquid with hydroxyl radicals and other radical species. The second mechanism occurs when solutes interact with the plasma interface. Therefore, production of greater plasma area tends to improve the removal of surface active compounds such as PFASs.
Journal Articles on this Report : 4 Displayed | Download in RIS Format
| Other project views: | All 22 publications | 6 publications in selected types | All 6 journal articles |
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Dai F, Fan X, Stratton GR, Bellona CL, Holsen TM, Crimmins BS, Xia X, Mededovic Thagard S. Experimental and density functional theoretical study of the effects of Fenton’s reaction on the degradation of bisphenol A in a high voltage plasma reactor. Journal of Hazardous Materials 2016;308:419-429. |
R835332 (2016) R835332 (Final) |
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Mededovic Thagard S, Stratton GR, Dai F, Bellona CL, Holsen TM, Bohl DG, Paek E, Dickenson ERV. Plasma-based water treatment:development of a general mechanistic model to estimate the treatability of different types of contaminants. Journal of Physics D:Applied Physics 2017;50(1):014003 (13 pp.). |
R835332 (2016) |
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Stratton GR, Bellona CL, Dai F, Holsen TM, Mededovic Thagard S. Plasma-based water treatment: conception and application of a new general principle for reactor design. Chemical Engineering Journal 2015;273:543-550. |
R835332 (2015) R835332 (2016) R835332 (Final) |
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Stratton GR, Dai F, Bellona CL, Holsen TM, Dickenson ERV, Mededovic Thagard S. Plasma-based water treatment: efficient transformation of perfluoroalkyl substances in prepared solutions and contaminated groundwater. Environmental Science & Technology 2017;51(3):1643-1648. |
R835332 (2016) R835332 (Final) |
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Supplemental Keywords:
Drinking water, chemicals, engineering, innovative technology, membrane filtration, advanced oxidation, plasma reactorProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.