Joel Ducoste

The proposed Annual Support Package is designed to build the foundation needed to develop the KEEN EM program at NC State. It includes a mix of faculty support to conferences and workshops provided by the KEEN network, the development of a Wolf Pack KEEN EM website, the development of the CEMENT (Creating Entrepreneurial Mindset in Engineering Teaching at NC State) Workshop , and finally, the development of a certificate program that documents the level of faculty training in EM.

In North America, temperatures nearing 100 ���������������� have been reported in a few municipal solid waste landfills. Elevated temperature landfills (ETLFs) have unique characteristics and challenges including substantial changes in the composition and quantity of landfill gas (LFG) and leachate, rapid waste subsidence, and, in some cases, elevated liquid and gas pressures. In an effort to understand the key chemical and microbial processes that lead to heat accumulation, we developed a batch reactor model (BRM) which describes all sources of heat input, generation and loss in a typical Subtitle D landfill. While the BRM can generate temperature predictions in a matter of seconds, it cannot predict spatial variations in temperatures that would be essential in assessing disposal strategies that mitigate heat accumulation. Recently, we developed a transient 3-dimensional finite element model to incorporate spatially-dependent waste composition, heat generation and transfer processes, waste disposal strategy, landfill geometry and operating conditions to address the limitations of the BRM. Although this 3D model was effective in demonstrating the propagation of heat through a landfill, the model������������������s solution time is ~4 days on desktop computers using a licensed software (COMSOL) and it is impractical for use on portable devices. To facilitate the need for landfill owners to predict waste temperatures as a function of waste composition and operating strategies, a simplified 3D modeling tool is needed that can rapidly generate results on multiple computing devices. The objectives of the proposed research are to (1) develop an open source compartmental landfill reactor heat (CLRHeat) model to describe spatial heat generation, transfer and accumulation, (2) verify the CLRHeat model using field and/or 3D finite element model data, and (3) develop a graphical user interface (GUI) to simplify the required data to describe a landfill and ease of use of a 3D predictive tool.

TSA: UV Modeling of work space to simulate COVID virus reduction using Computational Fluid Dynamics

Recently, there have been reports of municipal solid waste (MSW) landfills that have been experiencing temperatures in excess of 80 ���������C. Elevated temperatures have a number of deleterious effects that are well known to landfill owners. Consequently, elevated temperature landfills often require increased monitoring and management. In recent work supported by the EREF, we developed a model of heat accumulation in a landfill. The objective of the model was to help identify and mathematically describe all sources of heat input, generation and loss in a typical Subtitle D landfill. The model simulations identified several reactions that contribute significant heat to landfills including the hydration and carbonation of calcium-containing wastes (e.g., ash) and aluminum corrosion. Model predictions however, were based on information adopted from the literature for systems other than landfills. In addition to MSW, many landfills receive non-hazardous industrial wastes including ash from both coal and MSW combustion, ash used to solidify liquid wastes, auto shredder residue (ASR) that contains Al and Fe, and perhaps other Al-containing wastes. Methods are needed to measure the heat production potential of such wastes under landfill-relevant conditions and to use the resulting heat production data to evaluate the quantity of a given waste that can be disposed without the accumulation of unacceptable heat. The objectives of the proposed research are to (1) develop laboratory methods to measure heat evolution from special wastes under landfill-relevant conditions and (2) measure rates of heat production to parameterize our heat accumulation model. The model will then be used to estimate acceptable quantities of specific heat-producing wastes for disposal. The proposal emphasizes heat release from ash and metal corrosion. However, methods will be generalized to assess the heat generation of other wastes.

In the continuing quest to relate microbial communities in bioreactors to function and environmental and operational conditions, engineers and biotechnologists have adopted the latest molecular and ���������������omic methods. Despite the large amounts of data generated, gaining mechanistic insights and using the data for predictive and practical purposes is still a huge challenge. This project will use a methodological framework to guide experimental design to improve the operation, start-up, and resilience and resistance of anaerobic bioreactors co-digesting food and FOG wastes. This research represents leading edge work to combine molecular microbial methods, bioreactor experiments, and modeling to identify and exploit the underlying factors that govern microbial community assembly in anaerobic co-digestion systems.

According to the US Environmental Protection Agency (USEPA), around 23,000 to 75,000 Sanitary Sewer Overflows (SSOs) occur annually and approximately 25% of these SSOs are due to sewer line blockages related to the deposition of insoluble calcium salts of fat, oil and grease (FOG). Prior research studies have quantified the chemical and rheological properties of the FOG deposits along with its formation mechanism (Keener et al. 2008; He et al. 2011, 2013; Williams et al. 2012; Gross et al. 2017). Research performed by the PI and Co-PI on the project entitled ����������������Evaluation of Alternative Binder Material to Reduce Sewer Collection System Infrastructure Maintenance and Enhance Sustainability��������������� funded by WRRI, investigated the substitution of Fly Ash (FA) in concrete to reduce the formation and adhesion of FOG deposit on sewer line surfaces. Although exciting results from this project revealed a significant reduction in FOG formation and adhesion on FA replaced concrete surfaces, its mechanism for reduced FOG deposition at the interface is unknown. An interesting observation from these prior adhesion studies is that FOG deposits do not form or adhere on the concrete coarse aggregate (granite) surface. Understanding this unique and previously unknown phenomenon could lead to new strategies on treating pipe surfaces that would not allow any FOG deposit adhesion. The objectives of this proposed research are to: 1) understand the FOG adhesion mechanism on different sewer pipe surfaces and 2) evaluate the factors affecting FOG adhesion on different sewer surfaces. Successful completion of this project will help to determine the adhesion mechanism of FOG deposits on sewer collection system and develop new strategies during construction or the maintenance of sewer pipes that will change the surface characteristics to reduce the adhesion of FOG deposits. We anticipate that results will eliminate or significantly retard the accumulation of FOG deposits in sewer lines leading to a reduction in the maintenance cost and the occurrence of FOG related SSOs especially in ����������������Hot Spot��������������� regions known for the persistent accumulation of these solids.

The North Carolina Louis Stokes Alliance for Minority Participation (NC-LSAMP), requests a supplement to implement Cohort VII of the ����������������Bridge to the Doctorate��������������� program with North Carolina State University (NC State) serving as the institutional site. NC State University is a member since the beginning of the North Carolina Louis Stokes Alliance for Minority Participation. As one of the two flagship research universities in the University of North Carolina Education System, NC State������������������s world leadership in research and education makes it an ideal site for this phase of the NC-LSAMP Bridge to the Doctorate program. NC State university proposes to support a critical mass of 12 Bridge to the Doctorate fellows in each of the two years of this program. We have a firm written commitments from senior NC State University leadership in the College of Engineering and College of Science, to guarantee funding for BD Fellows through completion of their Ph.D. degree. We plan to develop new initiatives that will increase the percentage of BD fellows that complete their doctorate. Our proposed initiatives will help recruit, retain, and prepare researchers of the future in STEM beyond the timeline of this BD program and change the culture at NCSU for underrepresented graduate students in STEM. At NC State University, our goals are 1) to broaden participation of underrepresented students pursuing a graduate degree, 2) to improve graduate student mentoring and develop a Presidential style advisory panel structure for each student, and 3) to provide workshops on research methods and transition from undergraduate to graduate school for graduate students.

Myo-inositol phosphates (InsPs) are signaling molecules that are critically important in a number of developmental, metabolic and signaling processes in eukaryotes. The fully phosphorylated form, inositol hexakisphosphate or InsP6, plays important roles in many eukaryotes. A new frontier for InsP signaling is the study of unique signaling roles for a novel group of InsPs containing diphospho- or triphospho- moieties (PPx) at one or more positions on the Ins ring. In some ways, these PPx-InsPs are analogous to ATP in that they contain high-energy pyrophosphate bonds, and in addition, have been linked to communicating the energy status of the cell in other organisms. In this collaborative project, we previously developed analytical methods to detect and quantify PPx-InsPs in plant tissues, identified and cloned genes encoding the VIP kinases that are responsible for inositol pyrophosphate production in plants, and developed genetic resources to examine function of the Vip genes. Our preliminary data using mutants lacking both Vip genes reveal these genes are key in signaling the energy status of the plant cell. Further, we have identified a possible mechanistic link between inositol pyrophosphate signaling and a major regulator of eukaryotic metabolism, the Sucrose non-fermenting related kinase 1 (SnRK1). Given the immediate need to understand and manipulate plant bioenergy, the long-term goal of this project is to understand how InsP6, InsP7 and InsP8 convey signaling information within the cell. We focus on these molecules in plants, but point out that our model and findings are applicable to understanding the InsP6 signaling hub in other eukaryotes. During the proposed project, we plan to address several unresolved questions pertaining to PPx-InsPs and energy by first adding to a preliminary kinetic model of this signaling pathway.

NC State's EFRI PSBR program will model, develop, implement, and evaluate a scalable photosynthetic biorefinery (PSBR) that uses transformational nutrient recycle processes and supports efficient conversion of CO2 to lipid (oil) in a marine microalgae-based system. Algal oils are an ideal feedstock for biofuels production, offering high production density and the ability to use marginal water (municipal wastewater, brackish water, etc.) and reuse CO2 in flue gases. However, there are a number of technical challenges associated with culturing algae in current generation PSBRs. Using a tightly coupled synergistic approach employing both Engineers and Biologists, the team will: a) genetically engineer a marine microalgae species (Dunaliella spp.) with enhanced CO2 uptake/fixation and the capability to recycle N and P from microalgal biomass; b) design a small-scale PSBR informed by our kinetic model which will be used to develop a scalable dynamic reactor model based on computational fluids dynamic simulation of the PSBR; c) develop innovative, scalable approaches for algal harvesting and lipid extraction; and d) develop an analytical framework for the LCA of our microalgal PSBR system to include creation of flexible and scalable cost and LCI process models that will ultimately lead to generation of a robust PSBR life-cycle decision tool that can be applied to this and other PSBR systems. Intellectual Merit New technologies developed as a result of this project for scalable, sustainable culturing of phototrophic marine microalgae for optimized algal oil production will broaden scientific discovery and create the framework, synergy and momentum for biologists and engineers to further explore rational design and operation of PSBRs. Genetic enhancement, reactor modeling, and LCA will be used to optimize production of algal biomass and lipids in our PSBR. Exploration of innovative and efficient means for algal CO2 uptake/fixation, cell harvesting, lipid extraction, and nutrient and water recycle, will transform the scientific development of algae-based biorefineries. Demonstration of novel Lagrangian microsensors that can assess accumulation of light radiation in proportion to its exposure during transport through the reactor will significantly aid in the modeling and testing of PSBR operation in response to light. PSBR design optimization enabled by our experiment-informed kinetic and CFD modeling and LCA will advance knowledge in rational microalgal-based PSBR design and operation, ultimately leading to development of fully scalable and sustainable biofuel feedstock production systems. Broader Impacts The development of truly scalable and sustainable PSBRs offers tremendous economic and environmental impact by reducing the transportation sector?s reliance on fossil fuels. This increases the prospect of finally being able to fully exploit the promise of algae as a biofuels feedstock, given that production of algal-oil derived biofuels that are fully compatible with all existing infrastructure has been demonstrated. Innovative and transformative enabling-technologies that will permit robust production of marine microalgae biomass and lipids in scalable and sustainable PSBRs will bring significant environmental and economic benefits to the nation through the development of an efficient, high-yield alternative energy feedstock production platform. This interdisciplinary research among engineers, microbiologists, molecular biologists and plant physiologists provides unique training opportunities for high school, undergraduate, graduate and postdoctoral scholars to bridge traditional disciplines and become the new generation of scientists and engineers to develop renewable energy for future generations.

In this proposal, we present a novel paradigm for identifying putative cis-regulatory promoter targets that control the regulation of stress responses in plants. This paradigm will also be used to identify critical regulatory components that differentiate the regulatory stress response across different cell types. We first develop the computational and analytical infrastructure needed to build a dynamic model of the gene regulatory network from time-course transcription profile data that quantifies the stress response. Novel analytical model refinement techniques are proposed to reduce the space of feasible solutions, generate specifications for model validation experiments, and test functional redundancy in the response. Parallel computing architectures will be used to scale the implementation of these model refinement approaches to the size and complexity associated with gene regulatory networks. The dynamic model of the gene regulatory network will be used to identify relationships between genes, build corresponding functional modules, and identify putative cis-regulatory promoter targets and regulatory components that can be used to alter responses to biotic and abiotic stresses in plants. Previous cell-specific transcription profiling has indicated that cell types have distinct expression profiles and respond differently to stress. We will generate cell-specific time-course transcription profiles using experiment specifications derived from the dynamic gene regulatory network. These data will be used to create a cell-specific dynamic gene regulatory network for identifying regulators that are key in differentiating the stress response between cell types.

In North Carolina, it is estimated that over 10,000 SSOs occur annually, costing hundreds of thousands of dollars in clean-up. Of those blockages, 50% are related to FOG release into the collection system. The amount of FOG that are routinely discharged into the nation������������������s sanitary sewer systems is increasing as commercial food preparation and serving facilities and high density dwellings increase particularly in metropolitan communities. The migration to urban centers has increased the maintenance required by pretreatment coordinators in efforts to keep the sewer pipes free of FOG deposit related blockages. The statistics of SSOs from FOG deposits and their potential environmental impact indicate the need to examine methods to reduce the accumulation of FOG deposits in the sanitary sewer collection system and enhanced strategies that remove FOG deposit chemical precursors. In addition to sewer collection system problems, North Carolina is dealing with the unfortunate discharge of nearly 40,000 tons of coal ash from a major power provider into a major waterway. Over 5.5 million tons of coal ash is produced in NC, ranking NC 9th in the US in coal ash generation. There are 37 ash ponds in NC and the majority of them are not equipped with leachate collection system to protect groundwater. The increased use of fly ash in infrastructure materials, such as production of pipelines, could introduce a way to offset the fly ash created by coal-fired power plants and contribute to reducing the risk of future pond dam failures and contaminations of water resources. The objectives of the proposed research are to: (1) Evaluate alternative binder materials used in precast concrete that significantly reduces or eliminates calcium leaching, (2) Evaluate the adhesion properties of FOG deposits on these alternative concrete surfaces, and (3) Assess the structural durability of these alternative concrete materials. The proposed research project will be the first to explore the FOG deposit formation potential and adhesive properties of alternative concrete materials using geopolymers. The research results of this project will offer North Carolinian wastewater municipalities with strategies to maintain a sustainable sewer collection system in high density metropolitan cities that are experiencing significant growth and alleviate the potential environmental and public health harm from FOG related SSOs as well as an avenue for offsetting the disposal of fly ash.

We propose to prove that aerobic granulation in lab-, pilot-, and full-scale activated sludge systems can be induced by engineering the bioreactor to have variable shear distribution. This project will thus impact wastewater treatment plant design and operation by increasing settling, improving organic contaminant removal efficiencies, decreasing reactor volume, and increasing organic and nutrient loading.

Plant cell walls are the essential components of feedstocks for biomass based liquid fuel alternatives to petroleum. The secondary cell walls of woody plants contribute greatly to biomass and are targets for improving potential feedstocks. In the application of systems biology to development of new biofuels, as in any complex biological process, predictive modeling is the central goal. We propose to use a systems approach with genome based information and mathematical modeling to advance the understanding of the biosynthesis of the plant secondary cell wall. To do this, we will use multiple transgenic perturbations and measure effects on plants using advanced quantitative methods of genomics, proteomics, and structural chemistry. The combination of quantitative analysis, transgenesis, statistical inference and systems modeling provide a novel and comprehensive strategy to investigate the regulation, biosynthesis and properties of the secondary cell wall.

Fat, oil, and grease (FOG) deposits are calcium based saponified solids that clog sewer lines that potentially lead to sanitary sewer overflows (SSOs). SSOs can pose a significant threat to public health due to the exposure of pathogens and other harmful contaminants. While recent research studies have provided new insights into the chemical characteristics of these insoluble FOG deposits as well as the chemical, physical, and environmental factors that influence the amount and rate of their formation, detailed research has yet to be performed that provides a fundamental understanding of how the maintenance schedule and the parameters used to assess the current state of GI readiness for continued FOG separation provides true protection against the formation of FOG deposits in sewer collection systems. Therefore, the objectives of this research study are as follows: 1) Develop a method to determine the concentration and profile of long chain free fatty acids (LCFA) in the GI effluent, 2) Determine the impact of GI pump out frequency on the effluent LCFA profile and concentration, and 3) Determine the effectiveness of the 25% combined solids and FOG layer thickness protocol on the GI effluent LCFA profile and concentration

Lignin is a unique and complex phenylpropanoid polymer, important in plant development and response to environment. We propose to advance our knowledge of lignin biosynthesis by developing a comprehensive pathway model of regulatory and metabolic flux control mechanisms. Our primary tool will be systematic gene specific perturbation in transgenic Populus trichocarpa. We will perturb all 34 known lignin pathway and regulatory network genes in P. trichocarpa using artificial microRNA (amiRNA) and RNAi suppression. From each independent transgenic perturbation, we will obtain quantitative information on transcript and protein abundance, enzyme kinetics, metabolite concentrations, and lignin structural chemistry. Using statistical correlation and path analysis, we will integrate this information to develop a mechanistic-based signaling graph and metabolic flux model for the pathway and its regulation leading to specific lignin structures. This model will reveal regulatory constraints on steady-state flux distributions and show how genes and other process components affect flux activity of lignin precursors, composition, and linkages. In this way, we will provide a systems biology approach to this fundamental pathway. There are few opportunities in higher plants to integrate genomics, biochemistry, chemistry and modeling to develop a comprehensive understanding of biosynthesis and structure of a major component of morphology and adaptation.

The proposed research plan seeks to integrate bench-scale and pilot-scale experimental and numerical techniques for comprehensive characterization of an ultraviolet light emitting diode (UV LED) continuous flow reactor. Data from bench and pilot scale experiments will provide the necessary information to develop and validate a computational fluid dynamics (CFD) model of a UV LED disinfection system. The validated CFD model will be combined with a heuristic optimization routine to develop an efficient continuous flow UV LED system based on a desired optimality criteria (i.e., minimize the total power input while achieving the required effluent log inactivation or maximize the effluent log inactivation given a target total power input). Overall, this research will allow engineers to determine whether UV LED based continuous flow UV reactor systems can achieve high disinfection system efficiencies and offer an alternative technology that replaces mercury vapor UV lamps. The acceptance of UV as an effective disinfection process for treating drinking water sources and its potential use in water reuse applications have led to considerable growth over the last 10 years. Such growth has ignited researchers to look at not only improving the effectiveness of UV reactor designs but also performing research to discover novel ways to increase the power output of low pressure lamps, improve the efficiency of low and medium pressure lamps, increase the lamp operating life, and develop new UV emission sources. However, a majority of the UV lamp technology contain mercury, which is considered hazardous waste and poses environmental and public health threats if not properly disposed or if lamps are broken. Lamp breakage may occur during the transportation or installation of the lamps within the treatment process as well as by a foreign object strike while the UV system is in operation. Other UV light technologies that have emerged (i.e., pulsed and excimer lamps and UV LEDs), which do not contain mercury. However, little research has been performed with UV LEDs to assess their capabilities as an effective UV emission light source within continuous flow UV systems. This research program proposes to examine the UV disinfection efficiency of UV LED based continuous flow reactors by 1) performing collimated beam experimental tests that determine the UV response of target non-pathogenic microorganisms and fluorescence microspheres at multiple UV LED wavelengths, 2) developing a numerical model that describes the UV LED light distribution, UV dose distribution, and microbial log inactivation of continuous flow UV LED reactors, 3) performing pilot scale experiments on a UV LED reactor over a range of flows and UV transmittance to validate numerical models, and 4) developing an optimal UV LED reactor based on the output from a combined optimization routine and CFD model. Intellectual Merit: The proposed research represents one of the first comprehensive and direct efforts to quantify the disinfection performance of a distributed point light source within a continuous flow UV reactor that may lead to improved disinfection efficiencies without geometric constraints due to incorporation of a cylindrical light source. Previous studies have only investigated UV LEDs with bench scale tests to assess either log inactivation of a strain of E-coli or the degradation of phenol under advance oxidation conditions with peroxide. The proposed study is a necessary first step to evaluating this alternative UV light source as a benign replacement to the current mercury vapor UV lamps. Broader Impacts: This project will contribute to the education of one Ph.D. and one MS student in Environmental Engineering. These students will be selected from the pool of applicants to the Civil, Construction, and Environmental Engineering (CCEE) Department, with special consideration for applicants from under-represented groups. The graduate students will be extensively involved in all areas of research: 1) experimental design, setup, and execution, 2) development an

The proposed project seeks to understand and reduce the FOG deposits formation that lead to environmentally detrimental sanitary sewer overflows (SSO) in sanitary collection systems by achieving the following objectives: 1) perform detailed bench scale experimental tests that attempts to recreate FOG deposits and determine parameters that influence their formation rate, 2) develop numerical models that describes the FOG deposit formation kinetics, 3) perform bench scale tests to explore treatment methods to improve FOG deposit chemical precursor removal with grease interceptors, 4) perform pilot scale experiments on a sewer collection system that includes common piping structures, and 5) develop a modified EPA storm water management model (SWMM) to predict FOG deposit formation in sewer collection systems. Wastewater collection systems are an important part of meeting the Clean Water Act (CWA). Reducing FOG deposit formation in sewer collection systems will help reduce the occurrence of SSOs where grease deposits are the primary cause in 40 to 50% nationwide. SSOs introduce significant amounts of nutrients and emerging contaminants into river segments as well as pose a direct public health risk if spills occur on streets or in residential or commercial establishments. As identified in this solicitation, research is needed to develop efficient approaches to meet reliable and sustainable infrastructure goals, and to solve infrastructure related problems. Yet, no research exists that characterizes FOG deposit formation. The proposed project approach involves several tasks to achieve these objectives. Tasks associated with objective 1 seek to initiate saponification reactions with different concentrations of oils and fats over a range of temperatures, pH, calcium concentrations, and mixing intensities and assess the physical and chemical characteristics of the metal soap formed (i.e., moisture content, compressive strength, total oil and grease, mineral, and metal analysis, and fatty acid profiling). The data will be used to develop a FOG deposit kinetics model in objective 2. Final model selection and parameter estimation will be performed using Vanrollegham and Dochain (1998) selection and identifiability criterion. Tasks associated with objective 3 will consist of performing jar tests on restaurant waste streams using metal coagulants and polymers at different concentrations over a range of pH. Finally, tasks associated with Objectives 4 and 5 will measure the amount of FOG deposits formed at different locations in a pilot sewer collection system. The data from pilot tests will be used to validate a modified EPA SWMM FOG model that predicts FOG deposit formation. This study results are expected to provide new tools to assist utilities in meeting CWA requirements and provide better management of sewer collection systems. The EPA SWMM FOG model along with better knowledge of what influences and reduces the FOG deposit formation rate will also help utilities and design engineers assess the risk associated with the placement of new residential and commercial development on existing and future sewer collection infrastructure.

The objective of this study is to determine the efficacy of a proposed herbicide and how it compares to the current RootX formula.

The proposed research represents one of the first comprehensive and direct efforts to quantify FOG deposit formation rate in sewer collection systems. To the PIs? knowledge, this proposed project will be among the first studies to perform the following: (1) quantify the impact of kitchen wastestream and food service establishment (FSE) effluent quality on the FOG deposit formation rate utilizing a pilot scale pipe-loop system (2) assess the impact of FOG from food disposal units on the FOG deposits formation rate; and (3) assess the impact of pipe surface material on FOG deposit formation rate. Such information will be important to provide wastewater municipalities with strategies to maintain a sustainable sewer collection system in high density metropolitan cities that are experiencing significant growth and alleviate the potential environmental and public health harm from FOG related SSOs.

This is an REU supplement to an existing NSF award.

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.

The proposed research project will investigate ways to improve grease interceptor performance through novel experimental and numerical techniques. The experimental work includes field measurements of FOG from active grease interceptors located at different food service establishments (FSE). Tests will be conducted during peak FSE operation (i.e., breakfast, lunch, and dinner) as well as under varying conditions (i.e., upstream food grinders, high temperature discharge, detergents/emulsifiers). Data from these field tests will be used to develop a synthetic FSE wastewater that will be used to perform pilot scale grease interceptor tests. The pilot scale tests will also be performed under varying conditions observed during the field tests. Along with influent and effluent measurements, Fog and solid measurements will be performed spatially within the pilot scale grease interceptor. The data from these pilot scale measurements will be used to validate 3-D three?phase numerical models of the grease interceptor process. Once the model has been experimentally validated, the grease interceptor model will be used to explore alternative designs (i.e., inlet/outlet and baffle configurations) that can be used to improve the grease interceptor performance. The optimal design configuration determined from the numerical model will then be applied to the pilot scale grease interceptor. In addition to these grease interceptor analyses, the proposed research will explore the impact of sewer pipe material as it relates to FOG deposition and roots on the development of sanitary sewer overflows (SSO). This research will perform surface roughness tests and surface polarity tests on both pipe and root material to determine if there is any preferential deposition of FOG solids on these surfaces. Research will also be done to investigate the type of vegetation that are responsible for root intrusion into the sewer main and determine if the resulting surface area produced by these root intrusions is a function of vegetation type. Finally, the results of this research will be used to provide guidance to the International Association of Plumbing & Mechanical Officials (IAPMO) for consideration for inclusion into the Uniform Plumbing Code (UPC).

The proposed REU research program will support one undergraduate student to work along side a Ph.D. graduate student to perform bench-scale sequential disinfection tests with a non-biological surrogate.