Education

Research Description

Dr. Barlaz has been involved in research on various aspects of solid waste since 1983. Over this time, he has conducted research on biological refuse decomposition, methane production, and the biodegradation of hazardous wastes in landfills. He has participated in two state-of-the-practice reviews of bioreactor landfills. His research forms the basis for much of the work done to assess the impact of landfills on methane emissions inventories. Dr. Barlaz is also recognized for his research on the use of life-cycle analysis to evaluate environmental emissions associated with alternate solid waste management strategies. Most recently, he has been working on the processes that contribute to heat accumulation in landfills.

Publications

Landfill Codisposal of On-Site Vegetation and Coal Combustion Residuals: Implications for Gas Management

Cruz, F., Setz, M., Barlaz, M., & Varsho, J. (2023, March 17), ACS ES&T ENGINEERING, Vol. 3. https://doi.org/10.1021/acsestengg.2c00332

Neutral Per- and Polyfluoroalkyl Substances in In Situ Landfill Gas by Thermal Desorption-Gas Chromatography-Mass Spectrometry

Titaley, I. A., Cruz, F. B., Barlaz, M. A., & Field, J. A. (2023), ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS, 10(3), 214–221. https://doi.org/10.1021/acs.estlett.3c00037

Influence of Inoculum Type on Volatile Fatty Acid and Methane Production in Short-Term Anaerobic Food Waste Digestion Tests

Ding, H., Barlaz, M. A., de los Reyes III, F. L., & Call, D. F. (2022, December 9), ACS SUSTAINABLE CHEMISTRY & ENGINEERING, Vol. 12. https://doi.org/10.1021/acssuschemeng.2c04080

Per- and Polyfluoroalkyl Substances (PFAS) in Facemasks: Potential Source of Human Exposure to PFAS with Implications for Disposal to Landfills

Muensterman, D. J., Cahuas, L., Titaley, I. A., Schmokel, C., Cruz, F. B., Barlaz, M. A., … Field, J. A. (2022), ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS, 9(4), 320–326. https://doi.org/10.1021/acs.estlett.2c00019

Critical review on PFOA, kidney cancer, and testicular cancer

Stevenson, E. D., Kleinman, M. T., Bai, X., Barlaz, M., Abraczinskas, M., Guidry, V., … Chow, J. (2021). [Review of , ]. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION, 71(10), 1265–1276. https://doi.org/10.1080/10962247.2021.1975995

Development of Streamlined Life-Cycle Assessment for the Solid Waste Management System

Wang, Y., Levis, J. W., & Barlaz, M. A. (2021), Environmental Science & Technology, 55(8), 5475–5484. https://doi.org/10.1021/acs.est.0c07461

Evidence of thermophilic waste decomposition at a landfill exhibiting elevated temperature regions

De la Cruz, F. B., Cheng, Q., Call, D. F., & Barlaz, M. A. (2021), Waste Management, 124, 26–35. https://doi.org/10.1016/j.wasman.2021.01.014

Life-Cycle Assessment of a Regulatory Compliant US Municipal Solid Waste Landfill

Wang, Y., Levis, J. W., & Barlaz, M. A. (2021), ENVIRONMENTAL SCIENCE & TECHNOLOGY, 55(20), 13583–13592. https://doi.org/10.1021/acs.est.1c02526

Measurement of heat release during hydration and carbonation of ash disposed in landfills using an isothermal calorimeter

Narode, A., Pour-Ghaz, M., Ducoste, J. J., & Barlaz, M. A. (2021), Waste Management, 124, 348–355. https://doi.org/10.1016/j.wasman.2021.02.030

What Is the Best End Use for Compost Derived from the Organic Fraction of Municipal Solid Waste?

Sardarmehni, M., Levis, J. W., & Barlaz, M. A. (2021), ENVIRONMENTAL SCIENCE & TECHNOLOGY, 55(1), 73–81. https://doi.org/10.1021/acs.est.0c04997

View all publications via NC State Libraries

Grants

A Life-Cycle Comparison of Landfilling and Waste-to-Energy Combustion in Montgomery County Maryland

Montgomery County(12/06/22 - 12/05/23)

×

A Life-Cycle Comparison of Landfilling and Waste-to-Energy Combustion in Montgomery County Maryland

Sponsor: Montgomery County

Start Date: 12/06/22

End Date: 12/05/23

Abstract

The overall objective of the proposed project is to evaluate the environmental impacts (including greenhouse gas emissions) for three options for managing Montgomery County’s residual municipal solid waste (MSW). Option 1: Disposal at an out-of-state landfill, with transportation by truck, rail, or both. Option 2: Disposal at a new in-county landfill to be constructed on the County’s Site 2 properties in Dickerson, MD with transportation by rail, truck, or both. Option 3: Management at the County’s existing mass burn waste-to-energy (WtE) facility in Dickerson, Montgomery Count, Maryland with transport by rail.

Close

Characterization of Wood Samples

Kodama Systems, Inc.(8/15/22 - 12/31/23)

×

Characterization of Wood Samples

Sponsor: Kodama Systems, Inc.

Start Date: 8/15/22

End Date: 12/31/23

Abstract

The objective of the proposed project is to characterize the anaerobic biodegradability of wood samples. Characterization includes measurement of the total organic carbon, volatile solids (VS), moisture content and biochemical methane potential (BMP).

Close

Development of a fast-open source model to assess heat generation from alternative landfill disposal strategies

Environmental Research & Education Foundation(6/01/22 - 5/31/24)

×

Development of a fast-open source model to assess heat generation from alternative landfill disposal strategies

Sponsor: Environmental Research & Education Foundation

Start Date: 6/01/22

End Date: 5/31/24

Abstract

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.

Close

Comparison of Field Measurements to Methane Emissions Models at Municipal Solid Waste Landfills

Environmental Research & Education Foundation(3/01/22 - 3/01/23)

×

Comparison of Field Measurements to Methane Emissions Models at Municipal Solid Waste Landfills

Sponsor: Environmental Research & Education Foundation

Start Date: 3/01/22

End Date: 3/01/23

Abstract

Landfills are the dominant disposal alternative for municipal solid waste (MSW) in the U.S. It is estimated that about 50% of the 292 million tons of MSW generated in the U.S. were landfilled in 2018. Decomposition of organic matter in landfill generates CH4 and CO2 in a series of biochemical reactions. Methane represents a source of energy and when recovered, methane can offset the use of non-renewable fossil fuels. While landfills represent an energy source, they also represent a source of greenhouse gas (GHG) emissions as some methane is released prior to gas collection system installation, and some methane is not captured due to imperfect gas collection. In 2018, U.S. landfills were estimated to emit 180 Tg (million metric tons) CO2 equivalents (CO2e), making landfills rank as the third and fourth largest sources of anthropogenic methane in the U.S. and globally, respectively. We expect that there will be additional scrutiny of landfill methane emissions in the next few years as a result of increased emphasis on the control of greenhouse gas (GHG) emissions. Given the cost and effort required to make direct measurements, it is likely that state and federal regulators and policymakers will depend on models. It is thus essential for the waste industry to have a good understanding of the relationship between actual measurements and the predictive models that are currently used. The overall objective of the proposed research is to quantitatively evaluate the relationship between measured and modeled methane emissions for at least 4 landfills. In the proposed work, we will extend the 2016 analysis from one young (<3 years old) landfill without gas collection to a set of at least 4 landfills that are more typical (i.e., waste of varying ages and gas collection installed).

Close

Does the Disposal of PFAS-containing Special Wastes Impact Leachate PFAS Concentrations?

Environmental Research & Education Foundation(1/01/22 - 12/31/23)

×

Does the Disposal of PFAS-containing Special Wastes Impact Leachate PFAS Concentrations?

Sponsor: Environmental Research & Education Foundation

Start Date: 1/01/22

End Date: 12/31/23

Abstract

The presence of PFAS in landfill leachate is well established and expected given the wide array of consumer products in which PFAS has been used. In addition to municipal solid waste (MSW), Subtitle D landfills receive a range of other non-hazardous solid wastes including, for example, biosolids, auto shredder residue (ASR), PFAS contaminated soil, industrial sludges, and solidified RO concentrate and spent activated carbon from treating PFAS-containing water. The presence of PFAS in municipal wastewater and therefore biosolids is well-established and recently, we detected PFAS in ASR. Despite some understanding of PFAS sources, questions remain: (1) What might a landfill owner do to reduce or minimize the presence of PFAS in leachate? (2) Does the acceptance of PFAS-containing special wastes impact leachate PFAS concentrations given that MSW has been shown to release PFAS to leachate?

Close

AI-Enabled Hyperspectral Imaging Augmented with Multi-Sensory Information for Rapid/Real-time Analysis of Non-Recyclable Heterogeneous MSW for Conversion to Energy

US Dept. of Energy (DOE) - Energy Efficiency & Renewable Energy (EERE)(10/01/21 - 9/30/23)

×

AI-Enabled Hyperspectral Imaging Augmented with Multi-Sensory Information for Rapid/Real-time Analysis of Non-Recyclable Heterogeneous MSW for Conversion to Energy

Sponsor: US Dept. of Energy (DOE) - Energy Efficiency & Renewable Energy (EERE)

Start Date: 10/01/21

End Date: 9/30/23

Abstract

This project will focus on rapid/real-time analysis of domestic heterogeneous municipal biomass waste utilizing AI-Enabled Hyperspectral Imaging for developing conversion ready feedstock into cost effective and sustainable biofuel for selling price under $2.50 per gallon gasoline equivalent (GGE) by 2030. Municipal solid waste (MSW) is considered as an abundant potential source for biomass. This biomass, if used as a feedstock for fuel conversion operation will promote the sustainable fuel production and lower the prices. The heterogeneity of the MSW based on locations and time period can affect the biofuels or bioproducts. Therefore, the characterization of the MSW feedstock at macro and microlevel in terms of chemical and physical composition, at different speeds of conveyor system, at different times and collection sites will be studied.

Close

Development of a Perfluoroalkyl Substances (PFAS) Systems Analysis Tool (SAT) to Assist in Prioritization of Destruction Research and Management Decisions

US Environmental Protection Agency (EPA)(3/22/21 - 3/31/22)

×

Development of a Perfluoroalkyl Substances (PFAS) Systems Analysis Tool (SAT) to Assist in Prioritization of Destruction Research and Management Decisions

Sponsor: US Environmental Protection Agency (EPA)

Start Date: 3/22/21

End Date: 3/31/22

Abstract

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).

Close

Development of a Perfluoroalkyl Substances (PFAS) Systems Analysis Tool (SAT) to Assist in Prioritization of Destruction Research and Management Decisions

US Environmental Protection Agency (EPA)(6/11/20 - 9/30/20)

×

Development of a Perfluoroalkyl Substances (PFAS) Systems Analysis Tool (SAT) to Assist in Prioritization of Destruction Research and Management Decisions

Sponsor: US Environmental Protection Agency (EPA)

Start Date: 6/11/20

End Date: 9/30/20

Abstract

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).

Close

High Performance Nonwovens Bags

US Environmental Protection Agency (EPA)(10/01/20 - 4/30/22)

×

High Performance Nonwovens Bags

Sponsor: US Environmental Protection Agency (EPA)

Start Date: 10/01/20

End Date: 4/30/22

Abstract

Nonwovens Research - marked Confidential

Close

Anaerobic Decomposition of Cotton Fabric Under Simulated Landfill Conditions

Cotton, Inc. (No pre-award costs/accounts allowed)(1/01/20 - 12/31/22)

×

Anaerobic Decomposition of Cotton Fabric Under Simulated Landfill Conditions

Sponsor: Cotton, Inc. (No pre-award costs/accounts allowed)

Start Date: 1/01/20

End Date: 12/31/22

Abstract

The US EPA estimates that only about 15% of textiles were recovered for recycling in 2015 while 66% of textiles were disposed in landfills. Textiles that are manufactured from cotton represent an important component of the overall textile market. Cotton is comprised largely of cellulose and, under the anaerobic conditions that dominate landfills, cellulose is converted to methane and carbon dioxide. An understanding of the anaerobic biodegradability of cotton as used in various types of textiles is important to characterize the carbon footprint of cotton-based textiles in landfills. While there is considerable literature on the anaerobic biodegradability of a number of lignocellulosic substrates in landfills, including various types of paper, lumber, food waste, grass, leaves and branches, there is only limited literature on the anaerobic biodegradability of cotton and neither study was conducted under conditions that are designed to simulate a landfill. Methane and carbon dioxide are the ultimate endproducts of anaerobic biodegradation in landfills. The methane is particularly important because it is both a potent greenhouse gas as well as an energy source. There are several fates for the methane produced in landfills. Some methane is released to the atmosphere because gas collection systems are not 100% efficient and some methane is produced prior to gas collection system installation. In addition, landfills below EPA-described capacity levels are not required to collect landfill gas. Methane that is captured may be converted to energy (engines, turbines, boilers) in which case the landfill can claim credit for avoided emissions associated with energy generation from traditional sources. Finally, some methane is captured and converted to carbon dioxide in a flare with no energy recovery. To the extent that biogenic carbon (e.g., cotton) is not completely degraded, the undegraded carbon represents stored carbon. Carbon storage and the fate of methane are dominant factors in a landfill carbon balance. The objectives of the proposed study are to (1) evaluate the rate and extent of anaerobic decomposition of three types of cotton fabric under simulated landfill conditions and (2) compare the decomposition behavior of cotton fiber with a synthetic polyester. Three types of cotton will be tested including a bleached cotton fabric and cotton fabric with softer and durable press finishes. In addition, a synthetic fabric polyester will be tested. Materials will be tested in 8-L reactors that are operated to simulate optimal conditions in a landfill such that the results will represent the ultimate extent of biodegradation expected in a landfill. Reactor operating conditions include (1) incubation in a room at 37 ï‚°C, the optimal temperature for mesophilic waste decomposition, (2) addition of moisture and leachate recirculation to promote the distribution of microorganisms and substrate, and (3) maintenance of critical nutrients (N and P) at concentrations that will not inhibit waste decomposition. In addition, reactors will be inoculated with well decomposed refuse that is maintained in our laboratory. A mass balance will conducted at the end of the decomposition cycle by comparing the mass of added test material (as methane potential) to the measured methane and carbon dioxide and residual material. In addition, cotton fabric residue showing visible signs of decomposition will be used to explore how fiber morphology and crystallinity changes correlate with results of chemical and biochemical analyses. Changes in fiber morphology will be evaluated by scanning electron microscope (SEM) to measure changes is surface characteristics of samples that contain different types of finish. XRD will be used to evaluate changes in cotton cellulose crystallinity to evaluate the relationship between crystallinity and biodegradability.

Close