Grantee Research Project Results

2013 Progress Report: Integration of Filtration and Advanced Oxidation: Development of a Membrane Liquid-Phase Plasma Reactor

EPA Grant Number: R835332
Title: Integration of Filtration and Advanced Oxidation: Development of a Membrane Liquid-Phase Plasma Reactor
Investigators: Bellona, Christopher , Holsen, Thomas M. , Mededovic Thagard, Selma , Dickenson, Eric
Current 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, 2012 through August 16,2013
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 foot-print, and achieves a finished water quality better than treatment systems that require multiple technologies.

Progress Summary:

During the project period the research team completed Phase I of the project (Classification and Prioritization of Contaminants) and commenced work on Phase II of the project (Fundamental Bench-scale Plasma/Membrane Reactor). The team constructed two ceramic membrane testing systems including a bench-scale system, and a pilot-scale system. The pilot-scale system will be used for demonstration testing at the Big Bend water treatment facility in Laughlin, NV during Phase IV (Demonstration of Developed Technology). A brief summary of project accomplishments is provided below.

Phase I: The objective of Phase I was to develop a contaminant list and necessary analytical methods to quantify them in environmental samples. The compounds chosen are being, and will be used further to develop, optimize and evaluate the plasma/membrane system. The project team compiled a list of 260 regulated, unregulated, and emerging organic contaminants. Peer-reviewed literature was screened to identify reaction rate constants for the reaction of each organic contaminant (when available) with ozone (O₃) and the hydroxyl radical (•OH). Compounds then were binned according to their ability to be transformed by these oxidants including: 1) reacts quickly with O₃ and •OH (reaction constant (k) > 10⁸); 2) reacts slowly with O₃ but quickly with •OH; and 3) reacts slowly with both O₃ and •OH. Approximately 11 to 15 compounds then were selected from each bin based on occurrence in the environment, and the establishment of analytical methods at Clarkson or the Southern Nevada Water Authority. Because the plasma process is hypothesized to produce a variety of reactive species in aqueous solutions, the developed list (Table 1) will allow for an unbiased evaluation of the plasma process developed during the completion of the project. Analytical methods have been completed and validated for the compounds presented in Table 1.

Table 1. Organic contaminant list for plasma system development and optimization

Table 1. Organic contaminant list for plasma system development and optimization.

Reacts quickly with D₂/and DH=		Reacts slowly with D₂ and quickly with DH=		Reacts slowly with D2 and OH=
Compound	Type	Compound	Type	Compound	Type
Carbamazepine	Pharmaceutical	Diazepam	Pharmaceutical	Chloraceldaad	Regulated DBP
Sulfamethoxazole	Pharmaceutical	Iopromide	X-raycontranstiagent	Chlorophorm	Regulated DBP
Trimethoprim	Pharmaceutical	Ibuprofren	Pharmaceutical	TCEP	Flame Reardent
Caffine	Stimulant	1,4-dioxaine	Industrial use	PFOA	Industrial Use/GOCL3
Fluoxetine	Pharmaceutical	Meprobamate	Pharmaceutical	PFOS	Industrial Use/GOCL3
Naproxen	Pharmaceutical	Dilantin	Pharmaceutical	PFHxA	Indsrtrial Use
Tridosan	Pharmaceutical	DEET	Insecticide	PFHxS	Industrial Use
Acetaminophen	Pharmaceutical	Primidone	Pharmaceutical	PFBA	Industrial Use
Tridocarbon	Pharmaceutical	Simazine	Herbicide	PFBS	Industrial Use
Atenolol	Pharmaceutical	Atrazine	Herbicide	NDMA	DBP,ODCL3
Gemfibrozil	Pharmaceutical	MBTE	CCL3	Sucrose	Artificial Sweetener
Bisphenol-A	EDC			Muslo ketone	Fragrance
17ß-Estradiol	EDC,ODCL3			Diatrizoate	X-raycontranstiagent
				Trichloronitramethane	DBP
17-αEthinylestradiol				(chloropicrin)	DBP
Nitrobenzene	EDC,ODCL3

Phase II: The objective of Phase II is to conduct bench-scale studies to optimize the plasma process for contaminant destruction, elucidate reaction mechanisms, and evaluate system water quality. The project team commenced plasma optimization through an experimental matrix designed to identify the main parameters controlling the degradation of contaminants during plasma treatment. The team has constructed a plasma reactor consisting of a high-voltage power supply, a plasma reactor, and a cooling and recirculation system. Variables being evaluated include applied voltage, initial compound concentration, solution conductivity, recirculation flow rate, reactor type, reactor diameter, and grounded electrode plate area. Experiments were performed with three solutes, bisphenol-A, DEET (N,N-diethyl-meta-toulamide) and nitrobenzene. Results from degradation experiments indicate that applied voltage (Figure 1a), initial contaminant concentration (Figure 1b), reactor type (Figure 1c), reactor diameter, and grounded electrode plate area have a significant impact on contaminant degradation. A hybrid plasma reactor system (i.e., RVC high-voltage electrode with the grounded electrode suspended above the liquid surface) was found to achieve significantly faster degradation kinetics than the standard point-to-plane plasma reactor setup (Figure 1c).

Figure 1. Degradation of bisphenol-A (BPA) during bench-scale plasma experiments. Figure 1a: impact of applied voltage; 5 mg/L BPA, 350 μS/cm, 15°C. Figure 1b: impact of initial BPA concentration; 28 kV applied voltage, 350 μS/cm, 15°C. Figure 1c: impact of reactor type; 5 mg/L BPA, 39 kV, 350 μS/cm, 15°C.

Future Activities:

The research team will continue to optimize and engineer the plasma process through controlled experiments with single organic contaminants (Task 2A). Once these experiments are completed, the plasma process will be tested with a mixture containing the contaminants presented in Table 1 at environmentally relevant concentrations (i.e., at the ng/L concentration range). Plasma degradation experiments will be conducted in the presence of reactive species scavengers to elucidate reaction mechanisms (Task 2B). The bench-scale ceramic membrane system will be integrated with the plasma reactor, and several membrane types will be evaluated. The impact of dissolved organic matter on contaminant degradation will be evaluated by spiking organic contaminants into Raquette river water and performing plasma degradation experiments in the absence and presence of the ceramic membrane system (Task 2C).

Journal Articles:

No journal articles submitted with this report: View all 22 publications for this project

Progress and Final Reports:

Original Abstract

The 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.