Francis Lajara De Los Reyes III

This project is to provide an 8-week international research experience for NC State students to work in Malawi, with partners from Malawi University of Science and Technology and Mzuzu University. The research will focus on research gaps in Water, Sanitation, and Hygiene (WaSH).

The goal of the project is to develop a low-cost, portable auger-based technology that can reliably and hygienically empty a wide variety of pit latrines and septic tanks containing wastes with a range of moisture and trash contents. After extensive field and lab testing, we have finalized an EV design that was successful in emptying pit latrines in the field while successfully excluding trash. Two technologies have been developed: a mechanized trash excluder that actively rejects trash in a pit while allowing emptying of the fecal sludge, and a complete, low-cost system that uses a vacuum and an excluder to empty the de-trashed fecal sludge to pit-side containers (currently called ����������������Flexcrevator���������������). We also recently finished a generalized market/business analysis for both technologies. NC State������������������s focus during this part of the project will be to coordinate work with potential commercial partners and contractors to design, build, and test Design Validation (DV) trash excluders. The primary outcomes and results will be: ��������������� Design, build a minimum of five (5) DV trash excluder units and create the necessary documentation for Design Validation with an outside contract manufacturer (per New Product Development Guideline) ��������������� Testing a minimum of two units (2) units in Ghana with an interested commercial partner (iDE Ghana/Sama Sama) over the course of at least 7 months as a means to understand the performance of the unit and collect commercialization data. This information will be used to develop business model documentation in Ghana, including supply chain, marketing, financing, sales plan. ��������������� Testing of the two (2) units will also include a study led by NC State on gender impacts: how the trash excluder operation, access, ownership/business operation, and the how the business of pit emptying is affected by gender. The goal is to identify barriers to inclusive use of the device and define explicit ways to remove these barriers.

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.

While significant research has been conducted to date on the benefits and process limitations of co-digestion of GIW with municipal biosolids in a traditional anaerobic digestion process, there is very little knowledge on the benefits and limitations of co-digestion of GIW with municipal biosolids in a process that includes thermal hydrolysis pretreatment process (THP) upstream of the anaerobic digestion process. The proposed study would focus on understanding the benefits and process limitations of co-digestion of GIW with municipal biosolids that have been pretreated with THP. This study will also consider how GIW addition shifts the nutrient concentrations in the anaerobic digestion process and how the reduction in nutrient concentrations impacts microbial population and kinetics in the anaerobic digestion process (i.e., does reduced nutrient content result in less stress on the microbial population in the anaerobic digestion process). This research will benefit the City of Raleigh and other utilities that are considering implementing THP to enhance their digestion process to understand the benefits and limitations of GIW co-digestion with this process. This research will also help to provide much needed information for full-scale implementation of GIW co-digestion in a THP + MAD process, which would ultimately result in an additional outlet option for GIW.

Wastewater treatment with Anaerobic Ammonium Oxidation (Anammox) holds the promise of significantly reducing energy and chemical costs associated with nitrogen removal from wastewater The Anammox process involves the anaerobic conversion of nitrite to nitrogen gas with ammonium as the electron donor. While used more regularly in side-stream applications, the use of mainstream Anammox is still limited. Most of the challenges associated with widespread application of Anammox for mainstream nitrogen removal involve the Anammox bacteria being outcompeted by other, more robust organisms commonly found in wastewater and utilized for conventional nitrogen removal. However, in addition to process challenges there are also significant costs associated with a change in infrastructure. One novel possibility that may address both challenges would be to convert existing filter infrastructure into tertiary Anammox filters for mainstream nitrogen removal. For the past two years our research team operated a preliminary pilot Anammox filter at the Neuse River Resource Recovery Facility in Raleigh, NC. While the filter showed exciting promise (> 90% TIN removal in some cases), the controlled nature of the influent into our preliminary pilot filter limited the applicability of the results. This study would build on our experience, and push the frontier of research on sustainable nitrogen removal in wastewater treatment. The primary objective of this study is to compare a pilot scale tertiary Anammox filter to a traditional denitrification filter, under a range of realistic operating conditions. We hypothesize that the Anammox filter will lead to significant cost savings while achieving similar or superior results to a traditional denitrification filter.

Anaerobic digestion (AD) or co-digestion of food waste provides the dual benefits of enabling the sustainable production of energy while providing an alternative disposal option for these ubiquitous wastes. The key to economically feasible AD of food wastes is maintaining high and stable methane yields under various loading and substrate conditions. However, the interactions between substrate variability (different food wastes, loading) and microbial community adaptations are not known, even though these directly impact process resilience and resistance. This is an important issue in full scale operation, since the collected food waste can vary in type, strength, and characteristics on a seasonal, daily, or per load basis. The overall objective of this project is to understand substrate-community interactions to optimize anaerobic digestion of food waste, particularly to increase process resilience and resistance to varying waste types and loads. This will lead to operational procedures that can be used in full-scale implementation of AD of food wastes by municipal utilities and industry.

This is for an NSF ERc Planning Grant to prepare for an ERC proposal. SWIFT-MC������������������s vision is a future of sanitation and water infrastructure that supports the well-being of marginalized communities and supports sustainable development. These communities disproportionately bear the burden of environmental and health risks, and are not typically prioritized by advances in engineering and technology. To address this complex societal problem, SWIFT-MC will innovate sanitation and water infrastructure (SWI) through deep collaboration across disciplines (e.g., engineering, social and behavior sciences, public health) and active partnership and engagement with marginalized communities, policy makers, and technology designers and developers. As a result, the SWI will be designed, implemented, and maintained equitably to serve the needs of marginalized communities with unique community characteristics and constraints and to achieve desired system properties such as efficiency, flexibility, environmental sustainability, and resiliency.

North Carolina has been selected as one of eight pilot states in the Centers for Disease Control and Prevention (CDC) National Wastewater Surveillance System (NWSS). This system will provide information on the presence and persistence of SARS-CoV-2-like viruses in wastewater systems as a metric of community COVID-19 prevalence. This approach provides a relatively low-cost way to measure both symptomatic and asymptomatic COVID-19 infections without dependence on supply chains for clinical testing supplies or access to clinical testing. Wastewater surveillance can demonstrate trends in COVID-19 prevalence, direct action to protect public health, and allay concerns about the burden of disease when SARS-CoV-2 concentrations are low. NC State University will support this project by collecting, preparing, and shipping samples to the UNC laboratory (Rachel Noble, PI).

The primary goal of the proposed research is to elucidate COVID-19 infection dynamics by monitoring for SARS-CoV-2 RNA in wastewater and sewage in four major metropolitan areas of the US. Influent wastewater (~500 mL) and primary solids (~40 mL) will be collected at wastewater treatment plants serving populations > 100,000 in Los Angeles, Raleigh, Houston and Washington DC. Whenever possible, we will also collect sewage samples within the sewerage network to provide greater resolution of infection dynamics across a city. Samples will be stored at -80 C and analyzed by RT-qPCR when labs are open again. Normalization of SARS-CoV-2 RNA concentrations in wastewater to per capita mass loads using daily flow and population served will provide community-scale information on COVID-19 infection.This coordinated effort across four cities is a unique strength of this work. We hypothesize that the value of wastewater monitoring to track infection dynamics will be influenced by local factors (e.g., whether there is a combined or separate sewerage system, weather events, and wastewater strength) and therefore we chose four cities that represent a wide range of those parameters. There is also a wide range in diagnostic testing capacity across the four cities, with DC having done the most tests per capita and Houston the fewest. The value added of sewage surveillance to clinical diagnostic testing is likely greater in cities with lower testing capacity; we will use our data to test this hypothesis.

Building on our Phase I results, we will continue to improve and develop a low-cost, portable auger-based technology that can reliably and hygienically empty a wide variety of pit latrines and septic tanks (pits) containing wastes with a range of moisture contents. Thus one machine can be used in watery, low solids pits (e.g, as occur in Malawi), and high solids and trash pits (e.g., as occur in eThekwini municipality in South Africa). We envision that a successful device will be used by local entrepreneurs or local governments in emptying pits all over the world, thus reducing the dangerous, unhygienic, and undignified practice of manual pit emptying.

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.

Results from two recent studies have highlighted the value of analyzing wastewater sludge in addition to influent wastewater for tracking SARS-CoV-2 community spread. In a wastewater treatment plant in New Haven, CT, viral RNA concentrations in primary sludge samples were significantly higher than what has been reported in the literature for influent wastewater, even after accounting for a typical concentration factor in primary clarifiers (Peccia et al. 2020). Thickened activated sludge from a wastewater treatment plant in Ourense, Spain was a more sensitive measure of increases in SARS-CoV-2 concentrations than influent wastewater (Balboa et al. 2020). Therefore, the City of Houston may benefit from collecting and analyzing waste activated sludge samples for SARS-CoV-2 in addition to their ongoing monitoring of the virus in influent wastewater.

Our overall aim is to develop a simple, activity-based fluorescent labeling approach for selectively quantifying metabolically active ammonia-oxidizing bacteria (AOB) and archaea (AOA) in complex soil microbial communities. These specialized microorganisms obtain all of their energy from the oxidation of ammonia (NH3) and initiate this process through the activity of ammonia monooxygenase (AMO). Collectively, these microorganisms can have large impacts on the fertilizer applications to soils and can substantially decrease fertilizer N availability to crop plants. A simple and reliable method that can predict in situ rates of AMO activity in AOA and AOB could be a useful management tool that could help decrease fertilizer waste and environmental impacts of excess fertilizer applications.

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.

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.

Through the USAID STRIDE Scholarship Program, Visiting Research Scholar, Nathanial Alcantara, will conduct research activities on Molecular Profiling of the Prokaryotic Community in the Pitcher Fluid of Nepenthes Species from Mt. Makilin Forest Reserve, Philippines and Screening of the Bacterial Isolates for Insecticidal, Antimicrobial and Anticancer Activities

Our current WRRI-funded research (ending June 2014) has shown the potential of anaerobic co-digestion of GIW with wastewater-derived biosolids as a value-added disposal option. Our research resulted in several key findings4,5: 1) We achieved the highest methane yield ever reported for co-digestion (0.785 L CH4/g VS added, representing a 336% increase over the baseline). 2) We showed that step feeding as a strategy allows up to 75% (w/w) of volatile solids (VS) without overloading. 3) We demonstrated that high load pulses increased the digester resistance to GIW overloading. 4) Molecular microbial analysis using next generation sequencing is ongoing, but our pulse experiments suggest that changes in acid oxidizing bacterial communities are key. These results directly impact the economic feasibility of operating GIW co-digesters, specifically with respect to maintaining high methane yields. The overall objective of this project is to understand substrate-community interactions to optimize anaerobic co-digestion, particularly to minimize start-up time, and increase process resilience and resistance. The specific objectives are to: (1) Determine the key microbial populations that limit the anaerobic pathway to methane under different stress conditions such as overloading and GIW variability, (2) Influence these populations through active adaptation, and (3) Develop a procedure for producing a high yield yet resilient anaerobic co-digestion system that can be used in full scale applications.

North Carolina has a tremendous need for efficiently treating high-strength waste streams. These include agricultural residuals, food wastes, and wastewater-derived biosolids. Anaerobic digestion is one promising treatment and energy recovery method, but several limitations prevent widespread adoption. One of which is the instability that can arise from disruptions between key groups of microorganisms and another is the incomplete conversion of organics to methane gas (CH4). To overcome these limitations, we propose augmenting anaerobic digesters with electrically conductive micro-scale particles. These particles have proven effective as conduits for microbe-to-microbe direct electron transfer, resulting in improved rates of CH4 generation using pure strains in the lab. We hypothesize that supplementing anaerobic digesters with these particles will improve stability and CH4 recovery by strengthening interspecies electron transfer between the two central microbial communities: syntrophic bacteria and the methane-generating methanogens. Our objectives are to (1) determine the impact of various particle properties (type, conductivity, size) on organics removal and CH4 generation, (2) determine optimal particle loading densities for two distinct waste streams, and (3) assess the settleability of particle-augmented waste. To do this, we will operate lab-scale anaerobic digesters with and without conductive particles (activated carbon, magnetite, biochar). These findings will be especially beneficial for wastewater treatment facilities and farmers around the state looking for strategies to tip the economics in favor of anaerobic digestion technology while ensuring the health of our water resources.

This project will identify and bring together NCSU faculty and staff, funding agency personnel, corporate partners, NGO and foundations personnel, and other partners to plan and develop a major new research initiative at NCSU. The focus of the initiative is a multi-faceted research program on advanced bio-processing of organic residuals. The fundamental idea is that almost all global agricultural production eventually falls into one of four residuals streams: plant residual, animal residual, food waste, and human residual. Most current systems treat these residuals as waste such they are treated and disposed of at considerable pecuniary and environmental cost. At best, low value products such as soil amendments are derived. Recent scientific developments, declining natural resources, and environmental concerns have created the opportunity to develop new processes that use organic residuals as feedstocks. NCSU has strengths in several key areas of science and engineering and several interested corporate and funding agency partners.

In many rural and small communities in North Carolina, an aging and/or minimal wastewater treatment infrastructure is expected to achieve environmental standards while minimizing operational costs. Thus, any significant improvements in wastewater treatment performance that promise savings should be explored. This research aims to study the fundamental effects of a locally available product, kenaf, on the performance and microbiology of activated sludge wastewater treatment plants. Kenaf is an annual agricultural crop that is a member of the hibiscus family (Hibiscus cannabinus L.), and is related to cotton, hemp, and okra. It was introduced to North Carolina from Asia and Africa more than ten years ago, and can be processed to a powdered fiber that, when added to activated sludge mixed liquor, has been reported to: (1) improve nitrogen removal, (2) lower air requirements, (3) improve sludge settling, and (4) produce less biosolids for disposal. If substantiated, these claims could potentially lower wastewater treatment costs while supporting a local (NC)-grown crop. The proposed research will independently test the claims in laboratory-scale reactors using a combination of engineering methods, microscopic analysis, kinetics measurements, and molecular (DNA- and RNA-based) approaches. The combined methodology represents a more fundamental approach in determining the potential of kenaf, and elucidating the mechanisms by which kenaf addition works. If verified, kenaf addition to activated sludge treatment plants will provide a cost savings to small towns and may stimulate the demand for this crop.

Fat, oil, and grease (FOG) generated at food service establishments pose a threat to public health and the environment by reducing the conveyance capacity of our collection systems and causing sanitary sewer overflows. Grease abatement device pumping is a necessary step to maintain system performance. Presently in North Carolina, FOG waste pumped from the food service industry is treated as septage and either land applied or composted as a soil amendment. The anaerobic co-digestion of grease interceptor waste (GIW) provides a value added disposal option whereby GIW can be used to generate electricity at wastewater treatment facilities. No facilities in North Carolina currently utilize the anaerobic co-digestion of GIW. Preliminary research at NC State has shown the addition of GIW to result in increases in biogas production of up to 317%. The proposed research aims to: (1) Explore the limits to anaerobic co-digestion by varying the composition of GIW, (2) Explore bioreactor process and microbial community that is functionally resilient to variations in FOG loading and (3) Evaluate the quality of co-digested biosolids during experimentation for tasks (1) and (2). Findings from this research will provide guidelines for the sustainable disposal of GIW via anaerobic co-digestion and move wastewater treatment facilities towards renewable energy generation.

A workshop on microbial ecosystem services conducted with WUSL, Univ. of Maryland, and UC Merced.

Graywater (GW) constitutes 50-80% of the total household wastewater, and therefore GW reuse has tremendous impact in decreasing clean water consumption. Reuse options for the treated graywater include toilet flushing, irrigation, vehicle washing, fire protection, and cooling water supply, among others. Despite the potential of GW reuse in contributing to water resource sustainability, there are knowledge gaps with respect to GW characteristics, effectiveness of treatment systems, and public health risks. We propose to use molecular approaches to: (1) determine microbial communities in graywater (raw, collected, and stored); (2) quantify key pathogens using quantitative PCR; (3) determine the effects of various factors, such as source, storage time, household size and composition, soil composition, temperature, and hydrologic pulses, on the incidence and survival of pathogens in collected graywater and in irrigated soil; and (4) provide initial quantitative assessment of microbial risk associated with use of graywater for irrigation and toilet flushing. We expect this research to inform the water reuse community (municipalities, engineers, the general public) of the public health implications of water reuse.

The goal of this project is to develop and optimize a catabolic gene expression analysis system for monitoring functionally active microorganisms in complex environmental samples. The technique will involve sequential mRNA fluorescence in situ hybridization (mRNA FISH) followed by cell sorting by flow cytometry, allowing 16S rRNA gene analysis of the microbial populations actively transcribing the functional gene. The application will be on nitrate-, nitrite, nitric oxide, and nitrous oxide-reducing bacteria in activated sludge.

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.

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

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.

The overall objective of this project is to determine the relationships of sample processing procedures to the effectiveness and efficiency of three molecular techniques used in qualitative and quantitative analysis of microbial populations in groundwater and associated saturated soil samples.

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.

The ultimate goal of this study is to identify cost-effective wastewater treatment and disposal technologies available to small municipalities in NC with populations ranging in size from 500 to 5,000. The immediate objective is to conduct an assessment of the various swine technologies previously studied at NCSU, as well as various new and emerging treatment and disposal technologies and decentralized strategies, with a goal of identifying and ranking those systems with the highest potential of success for treating domestic wastewater from small rural communities. Since different communities have different treatment goals and different permit requirements, efforts will be made to identify systems that meet these different objectives.

This is an REU supplement to an existing NSF award.

The overall objective of the project is to determine the chemical and microbiological effects of biological drain products on grease interceptor (GI) characteristics and performance. The specific objectives are: (1) to identify the effects of bioaugmentation on the microbial community structure and function in grease interceptors; (2) to determine if there is a negative effect to downstream effluent from use of biological additives (i.e., determine if biaougmentation results in passing grease downstream); and (3) to start to address regulatory ordinances concerning biological drain products.

The objectives of the proposed research are to: 1. Develop an understanding of the conditions that are responsible for the production of hydrogen at the Waimanalo Gulch Landfill. 2. Characterize microbial populations in samples of refuse excavated from areas that are producing hydrogen as well as samples from laboratory-scale reactors that reproduce the hydrogen production observed in the field. 3. Use the information on microbial populations and reactor performance to propose strategies for the control of hydrogen production and excessive temperatures at the Waimanalo Gulch Landfill

The aim of this project is to develop, implement, and promote an interdisciplinary curriculum in environmental biotechnology at four campuses of a single university system. The curriculum is designed to teach both biology and engineering students some of the most up-to-date ways to apply biotechnology-based methods to solve environmental engineering problems, and it will require students to work collaboratively in interdisciplinary teams and to use inquiry methods to solve real-world ill-structured problems.

This is an REU supplement to an exisitng NSF CAREER Award. The project involves investigating the ecology of filamentous bacteria involved in activated sludge bulking problems. Funds from this REU supplement will be used to continue to employ two or more undergraduate students who will be involved in sampling, lab-scale reactor operation, and image analysis of fluorescence micrographs. The REU students will be employed throughout the academic year on an hourly basis as their schedules allow. The REU students will work closely with one MS student and one PhD student.

The main objective of this project is to determine the effectiveness of steam application in reducing activated sludge foaming. The specific objectives of the project are: (1) To construct a steam generator/test chamber apparatus for exposing activated sludge foam to steam. (2) To determine the effects of steam exposure times and temperatures on foam reduction. (3) To develop guidelines for applying steam for foam reduction in a full-scale wastewater treatment plant.