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Detlef Knappe

S. James Ellen Distinguished Professor

Fitts-Woolard Hall 3111


Detlef Knappe is the S. James Ellen Distinguished Professor of Civil, Construction, and Environmental Engineering at NC State University. He received his BS, MS, and PhD degrees from the Department of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign, and he joined the NC State faculty in 1996. He is the Deputy Director of NC State’s Superfund Center “Environmental and Health Effects of PFAS” and is a member of the Center for Human Health and the Environment.

Dr. Knappe is interested in drinking water quality and treatment, water reuse, organic micropollutants, development of water treatment processes for polar and persistent organic pollutants, and the fate of organic pollutants in solid waste landfills. He is a Trustee of the American Water Works Association’s (AWWA’s) Water Science and Research Division, and he is a member of the North Carolina Secretaries’ Science Advisory Board. He serves as Associate Editor for AWWA Water Science. He also serves on the AWWA’s Organic Contaminants Research Committee and the Standards Committee for Activated Carbon.

Detlef Knappe and his students have been the recipients of numerous best paper, best poster, and best thesis awards. He is a recipient of the NCSU Outstanding Teacher Award, the Bill Horn Kimley-Horn Faculty Award for excellence in graduate and undergraduate teaching and other accomplishments at NC State University, and the Young Civil Engineer Achievement Award from the University of Illinois.


Ph.D. Environmental Engineering University of Illinois, Urbana-Champaign 1996

M.S. Environmental Engineering University of Illinois, Urbana-Champaign 1991

B.S. Civil Engineering, University of Illinois University of Illinois, Urbana-Champaign 1989

Area(s) of Expertise

Dr. Knappe has conducted research on water treatment processes for over 25 years. Current research efforts focus on (1) developing and evaluating physical-chemical treatment processes for the control of disinfection byproduct precursors and trace organic compounds (taste and odor causing substances, carcinogenic volatile organic contaminants, 1,4-dioxane, per- and polyfluoroalkyl substances, endocrine disrupting chemicals, antibiotics, and other pharmaceutically active compounds), and (2) overcoming gaps between the Clean Water Act and the Safe Drinking Water Act by developing information about the effects of reactive and unregulated wastewater contaminants on drinking water quality and treatment. Funding agencies that have supported or are currently supporting his research include the U.S. Environmental Protection Agency, the National Institute of Environmental Health Sciences, the National Science Foundation, the Water Research Foundation, the North Carolina Water Resources Research Institute, and the North Carolina Urban Water Consortium.


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Date: 10/01/21 - 9/30/26
Amount: $15,147,874.00
Funding Agencies: National Science Foundation (NSF)

The Science and Technologies for Phosphorus Sustainability (STEPS) Center is a convergence research hub for addressing the fundamental challenges associated with phosphorus sustainability. The vision of STEPS is to develop new scientific and technological solutions to regulating, recovering and reusing phosphorus that can readily be adopted by society through fundamental research conducted by a broad, highly interdisciplinary team. Key outcomes include new atomic-level knowledge of phosphorus interactions with engineered and natural materials, new understanding of phosphorus mobility at industrial, farm, and landscape scales, and prioritization of best management practices and strategies drawn from diverse stakeholder perspectives. Ultimately, STEPS will provide new scientific understanding, enabling new technologies, and transformative improvements in phosphorus sustainability.

Date: 12/16/20 - 12/16/25
Amount: $424,087.00
Funding Agencies: Strategic Environmental Research and Development Program (SERDP)

The overarching goal of this research is to determine the fate of per- and polyfluoroalkyl substances (PFASs) during thermal reactivation of granular activated carbon (GAC) that had treated PFAS-laden water. Bench-scale studies will be conducted to determine reactivation conditions that release PFAS from spent GAC and lead to PFAS mineralization. To close the fluorine mass balance, this study will focus on laboratory-loaded GAC with known PFAS loadings. Limited experiments will be conducted with spent GAC from remediation sites with high PFAS levels.

Date: 07/01/23 - 6/30/25
Amount: $99,820.00
Funding Agencies: NC Department of Environmental Quality (DEQ)

The objectives of this research are to (1) identify multimedia sampling locations in the state of North Carolina for non-targeted PFAS analysis, (2) conduct non-targeted PFAS analysis of multimedia samples, and (3) share results with the North Carolina Department of Environmental Quality.

Date: 02/28/20 - 1/31/25
Amount: $9,234,563.00
Funding Agencies: National Institutes of Health (NIH)

Per- and polyfluoroalkyl substances (PFAS) are emerging as a major public health problem in North Carolina and across the United States. PFAS comprise a class of over 5,000 compounds. Their unique chemical properties have been harnessed to make consumer and industrial products more water, stain, and grease resistant; they are found in products as diverse as cosmetics and flame-retardants. PFAS are resistant to degradation, move easily through the environment, and accumulate in living organisms. Exposure to PFAS has been associated with health effects including cancer and toxicity to the liver, reproductive development, and thyroid and immune systems. Despite widespread detection in the environment and evidence of increasing human exposure, understanding about PFAS toxicity, its bioaccumulative potential in dietary sources such as aquatic organisms, and effective remediation remain notably understudied. The recent discovery by this proposed Center??????????????????s Deputy Director, Dr. Detlef Knappe, of widespread PFAS contamination in the Cape Fear River watershed in NC underscores that these compounds are in need of immediate investigation.. The goal of our Center is to advance understanding about the environmental and health impacts of PFAS. To meet this goal we are employing a highly trans-disciplinary approach that will integrate leaders in diverse fields (epidemiology, environmental science and engineering, biology, toxicology, immunology, data science, and advanced analytics); all levels of biological organization (biomolecule, pathway, cell, tissue, organ, model organism, human, and human population); state-of-the-art analytical technologies; cutting-edge data science approaches; a recognized track record in interdisciplinary, environmental health science (EHS) training; and well-established partnerships with government and community stakeholders.

Date: 03/28/22 - 12/31/24
Amount: $75,000.00
Funding Agencies: Hampton Roads Sanitation District (HRSD)

Incineration can destroy per- and polyfluoroalkyl substances (PFAS), but the conditions required for destruction are not known. This research aims to elucidate the fate of these compounds through sewage sludge incinerators (SSIs), and thereby provide utilities and decision makers with an indication regarding the extent SSIs can reduce PFAS discharges to the environment which is important for informing PFAS handling strategies.

Date: 01/01/21 - 12/31/24
Amount: $242,021.00
Funding Agencies: NC Department of Justice

The overall goal of this project is to identify the frequency of PFAS occurrence within swine sludge and biosolids to understand the risk of PFAS movement when these byproducts are applied to agricultural fields in the Cape Fear Watershed and other areas.

Date: 03/01/19 - 8/01/24
Amount: $350,000.00
Funding Agencies: Water Research Foundation

Poly- and perfluoroalkyl substances (PFASs) are contaminants of emerging concern for drinking water providers nationwide. As concerns about adverse health impacts have risen for long-chain PFASs, fluorochemical manufacturers have shifted their production to short-chain PFASs. As a result the detection frequency of short-chain PFASs in drinking water sources is increasing. The overarching objective of this research is to develop effective water treatment approaches for the control of short-chain PFASs. Treatment technologies, such as activated carbon adsorption, anion exchange, and high-pressure membrane filtration will be evaluated in both surface and ground water treatment contexts. In addition, innovative sorbents and destructive processes will be explored. Data generated in this study will inform life cycle analysis and cost models and will provide guidance for drinking water providers impacted by short-chain PFASs.

Date: 08/15/18 - 7/31/24
Amount: $180,000.00
Funding Agencies: National Science Foundation (NSF)

Development of water purification media for perfluoroalkyl contaminants via cyclodextrin grafted graphene oxide.

Date: 05/01/19 - 4/30/24
Amount: $700,000.00
Funding Agencies: US Environmental Protection Agency (EPA)

Per- and polyfluoroalkyl substances (PFASs) are persistent organic pollutants of global concern. Over 3,000 PFASs are on the global market, but for most PFASs we lack information about their properties, environmental fate and transport, bioaccumulation in foods of plant and animal origin, and human exposure. The overarching objective of the proposed research is to develop actionable information on the fate, transport, bioaccumulation, and relative exposures of understudied PFASs in PFAS-impacted communities. Information developed in this research is expected to enable risk managers to make informed decisions and reduce uncertainties related to human PFAS exposures.

Date: 03/01/21 - 11/30/23
Amount: $119,829.00
Funding Agencies: NCSU Water Resources Research Institute

North Carolina drinking water sources are vulnerable to impacts from a unique set of emerging organic contaminants, including per- and poly-fluoroalkyl substances (PFAS), pesticides, and pesticide degradates. The impact of these contaminants on the private well community in NC remains understudied. In this proposal, we will use the combination of ion mobility spectrometry (IMS) and mass spectrometry (MS) to extend a multidimensional database of toxicants, create a rapid analytical method suitable for organic contaminants, and apply this method to up to 50 private wells in NC.

Date: 04/01/19 - 9/25/23
Amount: $200,011.00
Funding Agencies: US Dept. of Defense (DOD)

Currently, an unbiased and comprehensive assessment of the various treatment technologies for the removal of per- and polyfluoroalkyl substances (PFASs) from contaminated groundwater is lacking. Such an assessment is needed to facilitate PFAS treatment selection. As a result of the current uncertainties regarding PFAS treatment technologies, we have assembled a project team with expertise in a variety of PFAS treatment technologies with the overarching goal of generating the data necessary to compare, on a life-cycle assessment (LCA) and costing (LCC) basis, established and emerging PFAS treatment approaches.

Date: 03/26/20 - 6/30/23
Amount: $46,600.00
Funding Agencies: Water Research Foundation

The overall goal of this project is to develop a comprehensive, methodologically consistent dataset regarding PFAS occurrence, fate, and mass distribution in wastewater treatment plants (WWTPs). This dataset will provide the scientific justification to develop appropriate guidance for site managers that benchmarks typical PFAS mass flows from WWTPs, sampling procedures and analytical methods, as well as potential mitigation strategies specific to WWTP unit processes. Specific objectives include: i) assessing the occurrence of a wide range of PFAS (32 target analytes and 325 precursors) and their fate in solid and liquid streams, ii) applying statistical tools to identify potential geographical or seasonal variables that impact WWTP susceptibility to PFAS, iii) determining the impacts of various treatment processes, including advanced treatment processes, on PFAS fate and partitioning, particularly PFAA precursor transformation, and iv) identifying key elements or data gaps in PFAS occurrence and fate in WWTPs to develop guidelines and mitigation/management strategies for PFAS.

Date: 09/02/21 - 8/31/22
Amount: $36,759.00
Funding Agencies: National Institutes of Health (NIH)

This three-day conference on ????????????????Highly Fluorinated Compounds ?????????????????? Social and Scientific Discovery??????????????? will examine the complex set of social, scientific, political, and environmental health issues raised by the recent discoveries of water contamination with high levels of highly fluorinated compounds. By bringing together scientists, government officials, activists, lay people, journalists, and lawyers, the conference can build on the diverse experiences and perspectives in order to better understand issues of science, regulation, remediation, prevention, and community engagement.

Date: 03/01/21 - 8/31/22
Amount: $10,000.00
Funding Agencies: NCSU Water Resources Research Institute

Approximately 30% of North Carolinians rely on private wells as their primary source of drinking water. Because private wells fall outside of the purview of the Safe Drinking Water Act, occurrence data are lacking for compounds such as pesticides. Furthermore, currently available analytical methods for pesticides target only a limited number of pesticides and do not keep up with the ever-evolving list of pesticides in use. Additionally, many pesticides partially degrade in the environment (e.g. via hydrolysis) and evidence of pesticide impact requires analysis for degradates in such cases. In order to more fully understand the impact that pesticides have on private well water quality, it is vital that we understand current use patterns for pesticides and the stability of these pesticides in water. To address this information gap, the proposed project aims to 1) assess the stability of the ten most widely used pesticides in NC and identify possible hydrolysis products and 2) investigate the occurrence of these pesticides and their degradates in NC private wells known to contain pesticides.

Date: 08/01/21 - 7/31/22
Amount: $110,320.00
Funding Agencies: Hazen and Sawyer

TSA "Water Quality Testing Using Rapid Small-Scale column tests for PFAS Removal by ION Exchange Resins"

Date: 03/22/21 - 3/31/22
Amount: $105,930.00
Funding Agencies: US Environmental Protection Agency (EPA)

The overall objective of this project is to develop and exercise a comprehensive systems analysis tool (SAT) to estimate PFAS release associated with management alternatives for a wide range of PFAS-containing wastes. In September 2020, we submitted the alpha version of the SAT as well as associated documentation. While this tool facilitates the comparison of alternative management strategies for PFAS-containing waste materials, it is not yet ready to be publicly released. The most critical next steps to advance the functionality and applicability of the tool consist of 1) reviewing and updating model input data, 2) developing PFAS-waste management scenarios and exercising the model to analyze predictions, and 3) upgrading the usability and functionality of the graphical user interface (GUI).

Date: 08/01/19 - 12/31/21
Amount: $336,834.00
Funding Agencies: NC Department of Transportation

The North Carolina Department of Transportation (NCDOT) routinely performs road improvement projects where a portion of the right-of-way might be contaminated. Based on the field evaluations carried out by NCDOT, at times subsurface utilities including water and/or drainage pipes are present, or need to be installed, in environments where soil and groundwater contamination exists. The currently funded project (RP 2017-08 with end date on July 31, 2019), is focused on the laboratory evaluation of contaminant migration through concrete pipes, as well as evaluation of the effect of contaminants on the mechanical performance of PVC pipe and three gasket materials (Neoprene, Buna-N, and Viton) when exposed to contaminated water. In addition, modeling of hardening methods and evaluating their efficacy is conducted as a part of the ongoing project.

Date: 10/01/19 - 8/15/21
Amount: $25,000.00
Funding Agencies: US Environmental Protection Agency (EPA)

Emerging contaminants are widely present in raw and treated drinking water and present an ongoing threat to human health, prosperity, and the planet. Per- and polyfluoroalkyl substances (PFAS), a broad class of fluorinated chemicals compounds used in a variety of industrial products, such as food packages, and household products, have been detected in drinking water across the country, including locally in Wilmington, North Carolina. Many PFAS are known or suspected carcinogens and pose a risk to humans even at trace levels (ng/L to ug/L). Moreover, they present a risk to the planet because they poorly degrade in the environment. The profound health risk of PFAS has therefore created an urgent need to develop viable methods and technologies to remove PFAS from water resources. The proposed technology in this project directly addresses the three aspects of sustainability because it will result in a cost- and energy-efficient PFAS removal method that can be readily adopted in households across the US. Furthermore, this project will provide an excellent opportunity for educating the public, especially school students in the regional community, many of which have been exposed to PFAS-contaminated waters. To broaden our dissemination of our project and the concepts of sustainability, we will attend and present our results in regional science fairs, such as at the NC Science Festival.

Date: 05/16/18 - 5/16/21
Amount: $199,699.00
Funding Agencies: Strategic Environmental Research and Development Program (SERDP)

The removal of per- and polyfluoroalkly substances (PFASs) from contaminated groundwater is required to minimize human exposure to these compounds. Activated carbon is a widely used sorbent to remove PFASs, but it suffers from two limitations: 1) the inability to remove short-chain PFASs, and 2) the lack of cost-effective regeneration methods. The overall objective of this proposal is to electrically enhance adsorption of high priority PFASs onto activated carbon and electrically discharge them as an innovative, chemical-free regeneration technique.

Date: 03/01/18 - 12/31/20
Amount: $120,000.00
Funding Agencies: NCSU Water Resources Research Institute

Approximately 3.3 million North Carolinians (35% of the population) rely on private wells as their primary source of drinking water.1 Well water quality is not regulated at the state or federal level, despite several studies illustrating a link between well water contamination and adverse health outcomes.2,3 Moreover, well water can contain harmful organic contaminants such as pesticides, but occurrence data are sparse.4 Key goals of the proposed research are to characterize pesticide contamination in private well water across the state and develop information for the selection of effective home treatment devices.

Date: 11/01/17 - 10/31/20
Amount: $701,881.00
Funding Agencies: National Institutes of Health (NIH)

GenX is a perflourinated compound used and generated in the production of non-stick coatings. This chemical has been detected in the Cape Fear River in North Carolina, upstream of where the Cape Fear Public Utility Authority obtains drinking water for the City of Wilmington (population ~250,000), Brunswick County and Pender County, NC. In June 2017, community concern about this chemical in drinking water resulted in multiple public meetings of citizens trying to obtain information about their potential exposure and resulting health effects associated with consumption of drinking water. As a result of community concern, the chemical plant has reportedly stopped discharging GenX into the river. However community concern still exists. This project is designed to help address community concerns about GenX exposure and health effects. Little is known about how GenX is stored in the body, the toxicity of GenX, or how long the chemical will remain in the environment. To address these questions, we plan to conduct a community-based study of Wilmington area residents who are served by public utility water. We will work with community partners of the Cape Fear Riverkeeper and the New Hanover County Department of Health to help identify a representative sample of residents, to collect biological samples, and to keep the community informed about what is known about GenX and what the study finds. We plan to recruit ~400 Wilmington area residents (100 men, 100 women, 100 boys, 100 girls) to provide blood, urine, and drinking water samples and to complete a questionnaire on their water use history. We plan to analyze blood, urine, and drinking water for GenX and related perflourinated chemicals; blood and urine samples will also be used for clinical tests (lipid profile, thyroid function, liver function, and urinalysis). All results from the study will be shared with both the community as a whole and each individual participant. We will have a community advisory panel for the study to help advise about study protocols, methods of reporting back results to participants, and provide guidance on ongoing or new community concerns about GenX. This project leverages the expertise of NC State??????????????????s Center for Human Health and the Environment to respond to an emerging community concern.

Date: 06/11/20 - 9/30/20
Amount: $125,000.00
Funding Agencies: US Environmental Protection Agency (EPA)

The objective of this project is to develop a comprehensive systems analysis tool (SAT) to estimate PFAS release associated with management alternatives for a wide range of PFAS-containing wastes. Through this project, we will establish an analytical framework to rigorously describe alternatives for the management of individual PFAS-containing wastes, estimate PFAS release and the receiving medium (air, surface water, groundwater, land).

Date: 06/01/18 - 3/31/20
Amount: $5,391.00
Funding Agencies: NCSU Center for Human Health and the Environment

Perfluoroalkyl substances (PFASs) are a diverse group of synthetic chemicals used in a wide variety of industrial processes and consumer products. The short-chain PFAS GenX (2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoate) has been detected in drinking water from NC??????????????????s Cape Fear River downstream of a facility that generates GenX at an average concentration four times higher than the estimated safe level. Currently, little or nothing is known about the potential health effects of exposure to GenX. The overarching goal of this pilot project is to address this gap employing the nematode Caenorhabditis elegans (C. elegans) to identify toxic effects in reproduction upon exposure to this compound. We hypothesize that exposure of C. elegans to environmentally relevant concentrations of GenX will result in impaired reproductive function and alterations in transcriptome profile. To test this hypothesis the following two specific aims will be conducted 1) Characterize effects of exposure to a range of environmentally relevant concentrations of GenX on reproductive function including brood size, egg hatching rate, gonadal development, permatogenesis and oogenesis. and 2) Evaluate effects of GenX exposure on gene expressions by transcriptome profiling and qRT-PCR confirmation. Based on aim 1) one GenX treated group will be selected for transcriptome profiling and compared with control. This study will identify potential health effects of exposure to GenX that will guide future analysis of mixtures, guide validation studies in vertebrate animals and inform translation into exposed human cohorts.

Date: 01/01/13 - 3/30/20
Amount: $122,110.00
Funding Agencies: B2E, Inc.

Laboratory column and microcosm experiments will be conducted to evaluate the advantages and disadvantages of solid and liquid suspensions for adjusting aquifer pH and enhancing contaminant biodegradation.

Date: 07/13/15 - 12/31/19
Amount: $42,193.00
Funding Agencies: US Army Corps of Engineers

The overarching goal of this project is to develop methods to better characterize and model mass transfer of contaminants between higher and lower mobility zones and its impact on the long-term release of contaminants in groundwater.

Date: 08/01/16 - 7/31/19
Amount: $387,441.00
Funding Agencies: NC Department of Transportation

The North Carolina Department of Transportation (NCDOT) routinely performs road improvement projects where a portion of the right-of-way might be contaminated. Potential sources of contamination include underground storage tanks in the vicinity of the road improvement site, old unlined landfills, or abandoned industrial and agricultural operations with practices leading to soil and/or groundwater contamination. It has been reported by NCDOT in RNS#7406 that in several situations, subsurface utilities including drainage pipes are present in environments where soil and groundwater contamination exists. The effect of the contamination on the integrity and durability of the subsurface drainage pipes and gaskets is largely unknown but such integrity is a function of the type of contamination and the physicochemical properties of pipe, gasket, and other materials forming a given subsurface utility. In addition to the variety of contaminants and concentrations that prevail at these sites, a wide variation in soil geological formation and hydrogeological conditions exist across the state. While in general the groundwater table is expected to be high in the North Carolina (NC) Coastal Plain Physicographic region, it is expected to be deep in the Mountains. On the other hand, it is more likely that groundwater will feed surface water springs and streams in the NC Mountains. Therefore, a "typical" contaminated site is difficult to define. Accordingly, the adverse effect of subsurface contamination on drainage pipes and the efficacy of hardening measures are usually developed on a site-specific basis. Objectives of this project are to (i) catalog the prevalent types of contaminants and their concentrations at sites where subsurface utilities are installed, (ii) document the typical materials used in subsurface utilities and drainage systems in NC, (iii) quantify the effect of contaminants on the long-term durability of commonly used hardened and unhardened materials that are used in construction of subsurface utilities, (iv) quantify the rate and extent of migration of common contaminants through concrete utilities, (v) recommend effective hardening methods for different materials, and (vi) provide documentation and better understanding of the effect of subsurface utility installation on the contamination of groundwater and surface water through simulation of several typical scenarios. These objectives will be achieved through a multidisciplinary effort of the research team as outlined in the project plan. Objective (i) will be achieved through examination of available data from the NC Department of Environmental Quality (DEQ). If necessary, limited sampling of groundwater and surface water will be conducted in consultation with NCDOT in areas where subsurface utilities have been installed and contamination is known to exist or expected to occur. Objectives (ii), (iii), and (iv) will be accomplished through literature review and accelerated coupon testing in our laboratory. Objective (v) will be achieved by analyzing test results and literature data. Objective (vi) will be accomplished through numerical simulations.

Date: 09/01/16 - 5/31/19
Amount: $100,000.00
Funding Agencies: North Carolina Biotechnology Center

Crab shell and chitin derivatives have attractive properties that may significantly address heavy metal waste and microorganism management in water because they are chemically functional/tunable, renewable, sustainable, abundant, and cheap bio-based metal chelating agents (when used in the native form, its price is FOB $0.45/lb or less depending on marine animal source and supplier). It is one among a number of potential bio-based solutions that include banana peels, pyrolyzed coconut shells, and seashells. However, what makes the chitin sources more useful is that no only are they more abundant than the latter biomaterials, they are far easier to amass, require no expensive treatments, are cheaper, and from a technical perspective they have far more amino and carboxyl groups which can form very strong complexes with heavy metals. These functional groups are the water sequestering agents and are responsible for metal chelating. Other advantages of the chitin derivatives over traditional petroleum-based water sequestering agents are that chitin derivatives are not solubilized, they can be easily separated from the aqueous solution, and they have shown very effective antimicrobial activity (we have discovered that they kill Gram positive and Gram negative bacteria easily).

Date: 03/01/18 - 2/28/19
Amount: $10,000.00
Funding Agencies: NCSU Water Resources Research Institute

Per- and polyfluoroalkyl substances (PFASs) are important drinking water and groundwater contaminants. Recent estimates show that approximately six million US citizens are receiving drinking water with PFAS concentrations that exceed the health advisory level issued by the US Environmental Protection Agency. Because of the toxicological properties, stability, and widespread presence of legacy PFASs in the environment, fluorochemical manufacturers have switched to short-chain PFASs and fluorinated alternatives such as perfluoroalkyl ether carboxylic acids (PFECAs). Standard treatment methods, including activated carbon adsorption and oxidative treatments, are ineffective for the treatment of short-chain PFASs and PFECAs. The overarching goal of this proposal is to employ cyclodextrins for the treatment of both legacy and emerging PFASs.

Date: 03/01/18 - 2/28/19
Amount: $10,000.00
Funding Agencies: NCSU Water Resources Research Institute

1,4-Dioxane is classified as a likely human carcinogen, and an increased one in one million cancer risk is associated with a lifetime consumption of drinking water containing a 1,4-dioxane concentration of 0.35 ????????g/L. Data from the US Environmental Protection Agency show that 7 of the 20 highest concentrations of 1,4-dioxane in US drinking water (up to 13.3 ????????g/L) occur in the Cape Fear River watershed. In all 7 instances, the Cape Fear River served as the source of the treated drinking water. The overall goal of this research is to develop a biological treatment process to degrade 1,4-dioxane from drinking water relevant concentrations. Microcosm and biofiltration column experiments will be conducted with enrichment cultures derived from aquatic environments in North Carolina. The effects of biofilm attachment media (sand, granular activated carbon, carbonaceous resin) on 1,4-dioxane degradation rates and the production of degradation products will be assessed. Research products will include the cultures and knowledge necessary to develop biologically active filters to treat 14-dioxane at drinking water relevant concentrations. An effective biofiltration system would not only enhance the safety of drinking water but would also ensure that surface water-derived contaminants, such as 1,4-dioxane, are not introduced into groundwater at utilities practicing aquifer storage and recovery.

Date: 09/15/17 - 2/28/19
Amount: $35,000.00
Funding Agencies: National Science Foundation (NSF)

Per- and polyfluoroalkyl substances (PFASs) are contaminants of emerging concern because of their toxicological properties, widespread presence, and persistence in the environment. Most water treatment technologies are not effective for PFAS control. For example, we have shown that short-chain PFASs and perfluoroalkyl ether carboxylic acids (PFECAs) were not removed in a drinking water treatment plant equipped with advanced treatment processes. Also, activated carbon adsorption is ineffective for the removal of short-chain PFASs and PFECAs. In the research proposed here, we seek to design cyclodextrins that can strongly bind short-chain PFASs, including PFECAs. We propose to explore the newly modified cyclodextrins by developing PFAS-selective sorbents for drinking water and industrial wastewater treatment.

Date: 01/01/17 - 12/31/17
Amount: $25,000.00
Funding Agencies: NCSU Research and Innovation Seed Funding Program

Recent research has suggested that co-contamination of drinking water with fluoride (F), cadmium (Cd), and arsenic (As) may play a causative role in chronic kidney disease of unknown etiology (CKDu)The motivating factor of our research is to develop appropriate, low-cost treatment methods for water co-contaminated with F, Cd, and As. Our work will integrate the expertise and perspectives of researchers from NCSU??????????????????s College of Agriculture and Life Sciences (CALS), College of Engineering (COE), Center for Human Health and the Environment (CHHE) in the College of Sciences (COS), and from RTI International (RTI). The specific objective of this RISF research is to quantify the reaction kinetics and uptake mechanisms of F, Cd, and As for two low-cost water water-treatment methods, bone char sorption and contact precipitation. Treatment for these three ions is challenging, due to differing charges, surface interactions and speciation under different conditions. In the sorption method, animal bones are burned at high temperatures and brought into contact with contaminated water. Hydroxyapatite, the main component of bone, removes ions from solution through sorption to mineral surfaces and ion exchange. The contact precipitation method consists of adding calcium and phosphate solutions to contaminated water to promote precipitation of contaminants in flurapatite and calcium fluoride along existing mineral (e.g. bone char) surfaces.

Date: 09/01/15 - 9/30/17
Amount: $89,849.00
Funding Agencies: National Science Foundation (NSF)

Because of their persistence, bioaccumulation potential, and (eco)toxicity, long-chain perfluoroalkyl substances (PFASs) such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are being replaced with short-chain PFASs and fluorinated alternatives. Almost no information exists about the occurrence of fluorinated alternatives and their behavior during water treatment. The overall goal of the proposed research is to begin to fill this knowledge gap by studying one class of fluorinated alternatives, perfluoro(poly)ethers (PFPEs). Specific research objectives include (1) develop a quantitative LC-MS/MS method for the analysis of 13 PFPEs in water, (2) apply the LC-MS/MS method to (a) determine PFPE fate between a known PFPE discharge location and the intake of the Sweeney water treatment plant (WTP), which is operated by our industry partner, the Cape Fear Public Utilities Authority (CFPUA), (b) quantify PFPE concentrations and mass flows at the intake of the Sweeney WTP, (3) in close collaboration with the CFPUA, trace parcels of water through the Sweeney WTP to quantify PFPE removal/transformation in full-scale water treatment processes, and (4) trace parcels of water through the Wilmington, NC water distribution system to determine PFPE fate during drinking water distribution and use PFPE concentration data to estimate human exposure to PFPEs via consumption of drinking water.

Date: 08/16/14 - 8/31/17
Amount: $199,523.00
Funding Agencies: NC Department of Transportation

We propose to study the factors involved in reducing turbidity in construction site stormwater to determine the most appropriate method for selecting chemical treatments. This will involve the following steps: 1. Select a range (15-20) of sediment (soil) types from around the state to represent most of those that would be encountered in road construction. This will be done with the assistance of NCDOT regional and district staff using current construction projects as sources. These will be chemically and physically characterized thoroughly to determine if there are one or more properties which can predict flocculation success. 2. Test representative coagulants and flocculants with the sediments using both a paddle-type jar tester and manual (shaking) methods. 3. Determine floc characteristics and treated water quality to identify factors that lead to successful and unsuccessful treatment. Parameters that will be measured include particle/floc size and density, net charge, and turbidity over time. 4. From this work, determine the best screening method and test it on at least 5 active projects on which flocculants will be used.

Date: 02/05/15 - 3/18/17
Amount: $89,998.00
Funding Agencies: Water Research Foundation

The goal of this project is to evaluate the efficacy, design, and cost implications of using granular activated carbon (GAC) to remove precursors and pre-formed halogenated and non-halogenated carbonaceous (C) and nitrogenous (N) disinfection by-products (DBPs) of concern via the following objectives: 1. Evaluate the impact of GAC treatment on the profile and concentrations of C-DBPs and N-DBPs under various source water quality conditions including bromide and iodide concentrations, algal impacts, and polymer usage under carefully controlled bench-scale conditions and at pilot/full-scale. 2. Evaluate the impact of various chlorination strategies including raw/settled water chlorination followed by GAC, free chlorine alone, free chlorine + chloramines, GAC + free chlorine, and GAC + chloramines on the formation of regulated and unregulated C- and N-DBPs under various source water quality conditions. 3. Quantify the breakthrough of C- and N-DBP precursors (as measured by formation potential rather than precursor identification) as well as pre-formed C- and N-DBPs relative to total organic carbon (TOC) breakthrough. 4. Relate RSSCT data to pilot-scale data to establish scale-up approaches for precursors of unregulated DBPs as well as pre-formed C- and N-DBPs

Date: 10/24/13 - 9/30/16
Amount: $105,000.00
Funding Agencies: Water Research Foundation

The United States Environmental Protection Agency (EPA) is in the process of developing new regulations for carcinogenic volatile organic compounds (cVOCs) by granular activated carbon adsorption. The new regulation may include a group of thirteen currently regulated cVOCs plus up to eight cVOCs that are on EPA's Contaminant Candidate List. The objective of this project is to survey existing cVOC treatment facilities to collect information on current treatment practices and to estimate impacts of alternative regulatory constructs on capital and operational costs.

Date: 05/15/14 - 8/15/16
Amount: $120,531.00
Funding Agencies: NCSU-WRRI Urban Water Consortium

Recent data from a nationwide study evaluating drinking water quality indicate that the highest concentrations of the industrial solvent 1,4-dioxane occur in North Carolina. Objectives of this research are: 1. Through a literature review, identify possible sources of 1,4-dioxane and effective treatment options for 1,4-dioxane removal, 2. Through stream sampling campaigns, identify 1,4-dioxane sources and determine factors that control 1,4-dioxane concentrations in surface waters, 3. At the bench-scale, assess the effectiveness of existing treatment processes at North Carolina utilities for 1,4-dioxane removal and identify treatment conditions for effective 1,4-dioxane removal, and 4. Identify new treatment options for 1,4-dioxane removal. The results of the proposed research will provide needed information for water quality professionals to manage 1,4-dioxane discharges.

Date: 10/01/12 - 7/01/16
Amount: $99,995.00
Funding Agencies: Water Research Foundation

The United States Environmental Protection Agency is in the process of developing new regulations for carcinogenic volatile organic compounds (cVOCs) in drinking water. Apart from eight currently regulated cVOCs, up to eight additional cVOCs may be included in a new group regulation. To assess the impact of possible regulatory constructs on the cost of drinking water treatment, the effectiveness of treatment technologies for cVOC removal needs to be assessed. Two common cVOC treatment technologies are air stripping and granular activated carbon (GAC) adsorption. Models describing the performance of air stripping and GAC treatment processes for cVOC removal require accurate knowledge of Henry's Law and Freundlich adsorption constants for cVOCs. The principal objective of this project is to experimentally determine Henry's Law and Freundlich adsorption constants for up to 16 cVOCs in typical water matrices encountered in drinking water treatment. Results will be used to develop equations that describe the temperature dependence of Henry's Law and Freundlich adsorption constants.

Date: 03/30/11 - 3/30/16
Amount: $820,000.00
Funding Agencies: US Army - Corps of Engineers

The overall objective of this proposal is to further develop and demonstrate a process to enhance the sorption and/or degradation of TNT, RDX, HMX and perchlorate in soils by spray application of an amendment solution containing waste glycerol and a soluble humic material to the soil surface, followed by irrigation to carry the amendments deeper into the soil profile. The readily biodegradable glycerol will stimulate anaerobic biodegradation of the target contaminants and will reduce naturally occurring Fe(III) oxides and hydroxides to Fe(II). This Fe(II) will provide a reservoir of reducing power to maintain anoxic conditions in the soil and will enhance abiotic degradation of RDX and other contaminants. The humic materials will also maintain reducing conditions by consuming oxygen, enhance hydrophobic sorption, enhance covalent binding of TNT, and may potentially serve as electron shuttles, enhancing abiotic degradation by Fe(II). The humic material is also expected to enhance sorption of any heavy metals that may be present. Irrigation and transport of the amendments at least 0.25 m into the soil profile will be important to reduce fire hazards, generate more strongly reducing conditions, and increase treatment longevity. Our process builds heavily on prior work supported by SERDP (CU-1229) and ESTCP (ER-0434) which showed that a combined peat ? soybean oil treatment could be effective in reducing contaminant flux through the vadose zone. The major focus of this project will be to develop a practical, easy to deploy technology that does not generate a fire hazard and does not interfere with training activities. In this demonstration, an established and operational burn ground will be treated to reduce concentrations of perchlorate and other energetic compounds in the vadose zone. We propose to follow a phased approach consisting of: (1) laboratory column studies to identify mixtures of glycerol and/or humic materials that are effective in treating contaminated soils in situ and preventing leaching of contaminants deposited in the future; (2) medium scale field-pilot tests to evaluate treatment performance under representative field conditions; and (3) a large scale field demonstration of the technology on a heavily impacted burn area. At the end of each phase, there is a GO/NO GO Decision. Glycerol / humics treatment of soils should be applicable to a wide variety of DoD facilities including mortar and grenade ranges, tank targets, OB/OD areas, etc. This technology is not expected to replace lime treatment of training ranges. Rather, our approach will complement the lime treatment technology and should be applicable to many sites where lime treatment is difficult to implement (soils with high acidity, UXO, vegetated areas, etc.). Cost and performance of the proposed technology are expected to be comparable to lime treatment of surface soils.

Date: 08/15/14 - 10/31/15
Amount: $50,000.00
Funding Agencies: National Science Foundation (NSF)

The cyclic diether 1,4-dioxane is commonly considered to be a groundwater contaminant. However, recent EPA data illustrate that 1,4-dioxane is also present in many drinking waters derived from surface water. The problem is particularly acute in the Cape Fear River basin of North Carolina, where the highest 1,4-dioxane concentrations in US drinking water have been measured. The objectives of the proposed research are to (1) identify 1,4-dioxane sources, (2) establish the spatial and temporal variability in 1,4-dioxane concentrations and mass flows, (3) assess 1,4-dioxane removal by existing point-of-use (POU) treatment devices and identify adsorbent properties that govern 1,4-dioxane removal, and (4) develop fundamental process parameters that describe the oxidative transformation of 1,4-dioxane by O3/H2O2, UV/H2O2, and UV/chlorine advanced oxidation processes in a surface water treatment context.

Date: 03/22/11 - 3/22/15
Amount: $506,874.00
Funding Agencies: Strategic Environmental Research and Development Program (SERDP)

Electron donor addition can be very effective in stimulating enhanced reductive dechlorination (ERD) of chlorinated solvents and anaerobic biodegradation/immobilization of other groundwater contaminants. However, electron donor addition can result in the release of a groundwater ?plume? with reduced levels of O2, NO3-, SO42-, and elevated levels of dissolved Mn2+, Fe2+, CH4, organic carbon, salts, and naturally occurring hazardous compounds (As, etc.). There is growing concern about these ?secondary impacts? of anaerobic bioremediation processes. Objective: The overall objective of this research is to develop an improved understanding of the near- and long-term impacts to groundwater quality after implementation of in situ anaerobic bioremediation processes. This will include development and application of a general modeling approach for describing the natural attenuation of important secondary water quality impacts associated with electron donor addition. Specific objectives to be achieved during the three year duration of this project include. A. Formulate a general modeling approach appropriate for simulating the natural attenuation of electron donors and associated secondary impacts for a wide range of sites. The model approach and validation will be based on data from three intensively studied field sites -- Bemidji Crude Oil Spill, Cape Cod Wastewater Plume, and NAWC - West Trenton Chlorinated Solvent Spill. B. Assemble a database of secondary water quality impacts at ERD sites. Analyze the secondary plumes to determine a range of characteristics and natural attenuation mechanisms. Identify a set of representative Case Studies illustrating important aspects of secondary plume behavior. C. Use the validated model approach to simulate a series of synthetic plumes corresponding to end-member cases important to SWQI assessment. Use the simulation results to assess the potential for significant SWQIs at ERD sites based on site characteristics and remediation system design. D. Use the advanced model simulations and ERD parameter database to develop a draft protocol for estimating the likely extent and duration of secondary impacts at typical ERD sites. The protocol would address extent and duration of impacts, sampling needs, and modeling approaches.

Date: 01/01/11 - 12/01/14
Amount: $150,000.00
Funding Agencies: Water Research Foundation

The principal objective of the proposed research is to assess the effectiveness of innovative powdered activated carbon (PAC) adsorption and magnetic anion exchange processes for the removal of perfluorinated compounds (PFCs) from drinking water sources. Specific objectives include (1) determining whether blending of microporous and mesoporous PACs is advantageous for the removal of PFCs that cover a broad range of molecular weights, (2) evaluating the effectiveness of superfine PAC (S-PAC) for PFC removal, and (3) evaluating the effectiveness of a magnetic anion exchange resin for PFC removal. An important goal of the third objective is to identify effective resin regeneration strategies.

Date: 03/01/13 - 11/28/14
Amount: $87,964.00
Funding Agencies: NCSU Water Resources Research Institute

Bromide is a non-toxic compound, but its reactivity with chlorine during drinking water disinfection leads to the formation of brominated disinfection by-products (DBPs), including regulated trihalomethanes (THMs) and haloacetic acids (HAAs), that are more harmful to human health than chlorinated DBPs. The objectives of the proposed research are to (1) assess the spatial and temporal variability of bromide concentrations in North Carolina drinking water sources, (2) identify sources of bromide in North Carolina watersheds, and (3) relate bromide concentrations at drinking water intakes to DBP concentrations in drinking water. The expected benefit of the proposed research is the direct association between bromide concentrations in North Carolina drinking water sources and DBP levels. Such information will allow policy makers to establish acceptable bromide levels in surface water and, if necessary, develop bromide standards for watersheds.

Date: 07/01/13 - 9/30/14
Amount: $72,213.00
Funding Agencies: Chancellor's Innovation Fund (CIF)

A compact water treatment soure capable of displacing existing technologies due to it's lower cost of operation and potential zero-chemical operation for applications ranging from water treatment to sterilization to fertigation of agricultural water supplies is proposd.

Date: 10/01/12 - 9/30/14
Amount: $60,000.00
Funding Agencies: Water Research Foundation

The United States Environmental Protection Agency (EPA) is in the process of developing new regulations for carcinogenic volatile organic compounds (cVOCs) in drinking water. The new regulation may include a group of eight currently regulated cVOCs plus up to eight cVOCs that are on EPA's Contaminant Candidate List. The objective of this project is to survey existing cVOC treatment facilities to collect information on current treatment practices and to estimate impacts of alternative regulatory constructs on capital and operational costs.

Date: 10/01/09 - 9/01/13
Amount: $150,000.00
Funding Agencies: Water Research Foundation

The principal objective of the proposed research is to assess the effectiveness of sub-micrometer sized powdered activated carbon (PAC) for the combined removal of disinfection by-product (DBP) precursors and trace organic pollutants. Specific objectives include (1) evaluate the effects of PAC particle size on DBP precursor and micropollutant removal (as-received PACs versus sub-micrometer PACs derived from the as-received PACs), (2) identify physical and chemical PAC characteristics that are important for effective DBP precursor and micropollutant removal, and (3) evaluate the effectiveness of different process trains for DBP precursor, micropollutant, and PAC removal (conventional treatment, microsand-enhanced flocculation, ceramic microfiltration (MF) membranes preceded by coagulant addition). The proposed research will offer conventional surface water treatment plants with a potentially cost-effective treatment tool for meeting DBP standards that will require minimal capital investment. An expected side-benefit of sub-micrometer PAC treatment will be the effective removal of many trace organic contaminants such as taste and odor compounds, pesticides, and emerging organic contaminants.

Date: 05/01/10 - 5/01/13
Amount: $20,000.00
Funding Agencies: Suffolk County Water Authority

This is cost sharing for project 552413, 2009-2318, Original PINS Record 34982

Date: 05/01/10 - 5/01/13
Amount: $155,000.00
Funding Agencies: US Environmental Protection Agency (EPA)

This project will evaluate scale-up approaches for granular activated carbon (GAC) columns for a suite of organic contaminants at low influent concentrations, The project will assess the efficacy of the rapid small-scale column test (RSSCT) approach and will also evaluate existing and develop new predictive mathematical models to predict the performance of full-scale and pilot-scale GAC columns. These results will allow utilities to choose the most appropriate RSSCT design for contaminants of interest. A further objective of the project is to recommend RSSCT design approaches that may become components of the current American Water Works Association GAC standard.

Date: 09/05/08 - 1/31/11
Amount: $60,742.00
Funding Agencies: US Environmental Protection Agency (EPA)

Perform experiments to support the US EPA's program to evaluate safe disposal methods for contaminated building debris.

Date: 10/15/07 - 1/15/11
Amount: $21,899.00
Funding Agencies: NCSU Water Resources Research Institute

The purpose of this subcontract is to measure the assimilable organic carbon (AOC) concentrations of approximately 100 samples that will be generated in the project ?Impact of UV Location and Sequence on By-Product Formation.? AOC concentrations will be measured by a new flow-cytometric method that utilizes a natural consortium of bacteria from a local lake water.

Date: 01/15/09 - 1/14/11
Amount: $52,919.00
Funding Agencies: NCSU-WRRI Urban Water Consortium

The presence of biochemically active compounds (BACs) such as endocrine disrupting chemicals (EDCs), antimicrobial compounds, and other pharmaceutically active compounds in the aquatic environment is an issue of great importance. For example, EDCs can cause intersexuality in fish, and antimicrobial compounds may lead to the evolution of antibiotic-resistant bacteria. While it is unclear whether human health effects can be expected at the BAC concentrations commonly measured in drinking waters, the public is concerned about the presence of such compounds in their drinking water. Objectives of the proposed research are to (1) identify, through a review of the literature, what human health and ecotoxicological effects are associated with the presence of BACs in drinking water and surface water, (2) develop a HPLC-MS/MS method, with which the removal of approximately 30 representative BACs can be evaluated in bench-scale experiments, and (3) assess, at the bench scale, the BAC removal effectiveness of drinking water treatment processes that are currently employed by North Carolina Urban Water Consortium (UWC) members (coagulation/flocculation/sedimentation, powdered activated carbon adsorption, oxidation with potassium permanganate, ozone, and free and combined chlorine). The goals of the proposed research include (1) setting BAC concentration targets for finished drinking water and (2) identifying opportunities for enhancing BAC removal with drinking water treatment processes currently employed at UWC member utilities. Results of the proposed research are expected to provide the information needed to (1) improve BAC removal from NC drinking water sources, (2) develop a communication plan that will inform the public about BAC removal efforts at UWC utilities, and (3) respond to potential future regulatory actions related to BAC removal from drinking water and wastewater.

Date: 03/01/09 - 12/31/10
Amount: $50,000.00
Funding Agencies: NCSU Water Resources Research Institute

The goal of the proposed research is to develop two advanced wastewater treatment strategies (ozonation and activated carbon adsorption) that, when applied individually, are expected to provide (cost-) effective barriers against the release of BACs into North Carolina surface waters. Benefits of the proposed research include not only improved habitat for aquatic life, but also improved water quality for drinking water treatment plants that rely on surface water sources impacted by upstream WWTP discharges. The objectives of this research are (1) to measure BAC oxidation kinetics during ozonation of NC wastewater matrices and determine ozone doses required to achieve a one order of magnitude transformation of model BACs and (2) to identify suitable powdered activated carbon (PAC) types and effective PAC addition points in wastewater treatment plants and determine PAC doses that yield a one order of magnitude removal of model BACs.

Date: 02/01/06 - 1/01/10
Amount: $150,000.00
Funding Agencies: Water Research Foundation

The principal objective of this research is to investigate two innovative treatment methods for the control of earthy/musty odors associated with the presence of 2-methylisoborneol (MIB) and geosmin in drinking water. Treatment method 1 is an adsorption/reaction process based on the use of high-silica zeolites, a class of catalytic adsorbents that has not been studied extensively for water treatment applications, while treatment method 2 is an adsorption/oxidation process based on the combined use of high-silica zeolites and ozone (zeolite-enhanced ozonation). Specific objectives of this research are (1) to determine zeolite pore sizes and SiO2/Al2O3 ratios that are most suitable for the adsorptive/reactive removal of MIB and geosmin, (2) to assess the effects of co-adsorbing and preloaded NOM on MIB/geosmin removals by high-silica zeolites, (3) to measure ozone adsorption capacities and decomposition rates for zeolites of different pore structures and SiO2/Al2O3 ratios, (4) to compare MIB/geosmin removal rates achievable with zeolite-enhanced ozonation to those achievable with conventional ozonation, and (5) to compare bromate formation in zeolite-enhanced ozonation and conventional ozonation processes. The results of this research will show whether high-silica zeolites or zeolite-enhanced ozonation are cost-effective treatment alternatives for the removal of MIB and geosmin from drinking water.

Date: 08/25/04 - 12/31/09
Amount: $700,000.00
Funding Agencies: US Environmental Protection Agency (EPA)

The overall objectives of the proposed research are to (1) develop and validate a model to predict the behavior of chemical contaminants in refuse and (2) to measure the survival and transport of biological agents in landfills.

Date: 03/01/08 - 8/31/09
Amount: $50,000.00
Funding Agencies: NCSU Water Resources Research Institute

Taste-and-odor problems in drinking water are frequently a result of nuisance algae blooms in the water source. Apart from earthy/musty odors caused by methylisoborneol (MIB), geosmin, and trichloroanisoles, a range of other compounds have been implicated in off-flavors and odors. For example, fruity odors have been associated with ????-cyclocitral and linolenic acid, and fishy, grassy, and swampy odors can be caused by such compounds as dimethyl disulfide; dimethyl trisulfide; 1-hexanal; 1-heptanal; cis-3-hexen-1-ol; cis-3-hexenyl acetate; cis-4-heptenal; trans, trans-2,4-heptadienal; trans-2, cis-6-nonadienal; trans, trans-2,4-decadienal; 2,3-benzopyrrole (indole); and 2-isobutyl-3-methoxypyrazine. Many of these compounds have only been identified in the last 10 years and will be incorporated into this study along with compounds associated with earthy/musty tastes and odors. One objective of the proposed study is to extend a GC-MS/MS method for MIB and geosmin, which we are currently using in our laboratory, to a suite of about 15-20 taste and odor compounds that are commonly associated with taste-and-odor problems in drinking water. The analytical method utilizes a headspace solid-phase microextraction (SPME) step to concentrate analytes and has a detection limit of 1 ng/L for MIB and geosmin. A second objective is to apply the analytical method to (1) document the identity and concentration ranges of taste-and-odor compounds in NC drinking water sources and (2) evaluate the effectiveness of full-scale treatment practices for the removal of taste-and-odor compounds in NC drinking water treatment plants. Additional samples from selected distribution systems may be analyzed as well. The expected results of this research will help NC drinking water treatment plants identify which algal metabolites cause taste-and-odor problems in their source water. In addition, the effectiveness of existing treatment strategies for taste-and-odor compound removal will be determined.

Date: 01/01/06 - 7/15/09
Amount: $150,000.00
Funding Agencies: Water Research Foundation

The use of ultraviolet (UV) initiated advanced oxidation processes (AOP) are rapidly becoming an attractive alternative for the degradation of harmful organic contaminants that are not easily removed in conventional treatment processes for drinking water. In this study, AOPs utilizing UV and hydrogen peroxide (H2O2) will be investigated. The yield of such systems is a function of the chemical kinetics and reactor design. Optimization and control of these reactors is critical for predicting the end results while minimizing design and operation costs. While some numerical techniques have been developed for understanding the performance of these processes, they are limited in their applicability for analyzing full scale UV systems. As a result, engineers involved with UV/AOP system design will need more appropriate numerical tools that will assist them in optimizing efficient drinking water UV/AOP systems. The principal objective of this research is to evaluate Computational Fluid Dynamics (CFD) for modeling UV-initiated AOPs that will ultimately help engineers in consulting, research, and water treatment facilities analyze and design drinking water UV/AOP systems. Specific objectives are to 1) develop and validate a dynamic UV/H2O2 advanced oxidation CFD model that can be applied to the complex kinetic pathways for degradation of various water supply contaminants, 2) utilize CFD models to quantify the effects of non-ideal reactor hydraulics on the degradation of contaminants using the UV/H2O2 advanced oxidation process, 3) evaluate the impact of model parameters on simulation performance of UV-initiated AOP systems using low-pressure high-output and medium-pressure lamps, 4) optimize system design parameters, including the effects of multiple lamps, lamp arrangement, and lamp failure on the overall efficiency of the AOP system, and 5) determine the effects of secondary species, such as hydroxyl radical scavengers, on UV absorption, reactivity, and degradation of contaminants. The approach consists of several tasks. During tasks 1 and 2, collimated beam experiments will be performed to verify chemical reaction rate constants that are part of the target contaminant, Phenol, degradation pathway. Tasks 3-6 involve experimental validation of CFD/UV/AOP models. Tasks 7-10 investigate the impact of upstream and internal reactor configuration, lamps out of service, lamp aging, and water quality conditions on the UV/AOP performance. The experimental data from Tasks 7-10 will be used to evaluate the CFD model performance under those conditions. EEO calculations will be performed in Task 11 based on the data collected from Tasks 3-10. Finally, Task 12 will encompass the development of a UV/AOP design protocol that will provide guidance to WTP professionals on how to navigate through the UV/AOP design process using the experimental and numerical techniques presented in Tasks 1-11. Following the proposed experimental and mathematical developments, the expected results of this study include 1) an improved understanding of the impacts of hydrodynamics on UV/AOP reactor performance, 2) a higher degree of confidence on the application of hydrodynamic UV/AOP models for the prediction of and improvement of reactor performance, 3) the development of enhanced tools for the analysis of drinking water UV/AOP systems, and finally 4) the development of a detailed design protocol that provide engineers with a road map to cost effective evaluation and design of drinking water UV/AOP systems.

Date: 03/01/07 - 8/31/08
Amount: $50,000.00
Funding Agencies: NCSU Water Resources Research Institute

The principal objective of the proposed research is to develop an integrated assessment of a sequential photochemical oxidation/biological process for the mineralization of biochemically active contaminants (BACs) in wastewater treatment plant (WWTP) effluents. Specific objectives are (1) to evaluate the effects of the wastewater matrix on the removal rates of BACs (and associated biological activity) by a UV/H2O2 advanced oxidation process (AOP), (2) to examine if treatment of contaminated WWTP effluent with UV/H2O2 AOP enhances the mineralization potential of the BACs and their oxidation intermediates, and (3) to determine if receiving surface waters can effectively biodegrade photooxidation intermediates. Integral to this effort are (1) characterization of the photochemical oxidation process in terms of BAC conversion kinetics in WWTP effluent, (2) assessment of estrogenic activity exhibited by EE2 photooxidation products and antimicrobial activity exhibited by trimethoprim photooxidation products, (3) evaluation of the mineralization potential of 14C-labeled sulfamethazine, sulfadiazine, and diclofenac photooxidation intermediates, and (4) evaluation of the mineralization portential of photooxidation products in receiving waters conditions.

Date: 07/01/06 - 6/30/08
Amount: $171,790.00
Funding Agencies: NC Department of Transportation

The objectives of this research are to determine the effect of prolonged heating on (1) asphalt-aggregate bond strength and (2) the moisture sensitivity of asphalt mixtures. In particular, this study will first evaluate the performance of mixtures using the tensile strength ratio test (AASHTO T283), and second, study the effect of additive content and prolonged heating on the surface interaction between asphalt binder and aggregate.

Date: 08/16/03 - 9/30/06
Amount: $65,000.00
Funding Agencies: US Environmental Protection Agency (EPA)

The principal objective of the proposed research is to predict single-solute adsorption isotherms for currently regulated organic contaminants, organic compounds on the EPA Contaminant Candidate List (CCL), emerging contaminants (endocrine disruptors, pharmaceutically active compounds, personal care products), and chemical agents (nerve agents, blister agents, blood agents, selected biological toxins, and toxic industrial chemicals). Work completed to date showed that additional isotherm experiments were required to validate the model developed during the initial phase of the research. Isotherm experiments will be completed with four volatile organic compounds and with pesticides listed on the EPA CCL.

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