Morton Barlaz

The reliance on petroleum-based plastics and nonowovens coupled with a single-use throwaway culture has resulted in environmental consequences and concerns regarding the end-of-life management of these materials. Synthetic material use in nonwoven products accounts for nearly 66%.1 In recent years, the use of biopolymers such as polylactic acid (PLA), lignin, polyhydroxy butyrate (PHB), polycaprolactone (PCL) derived or modified from renewable sources in nonwovens has been promoted as an environmental solution to plastic pollution.2 For sustainable disposal of these biopolymers post their use cycle, especially for disposable hygiene products and wipes, these materials must demonstrate some degree of biodegradability. PLA, one of the most widely used biopolymers, is only biodegradable/compostable under controlled conditions.3 Furthermore, these biopolymers are often blended with other polymers and also require surface modification to achieve desired functional properties. Here, we propose to investigate the effect of a class of surface coatings ??? hydrophilic finishes, both model and commercial, on the adsorption kinetics and wettability along with the rate and extent of biodegradability of the modified biopolymer substrates, PLA, and blends of PLA with other relevant polymers, e.g., PCL, under controlled environmental conditions.

The objective of this research is to modify a finite element model of heat accumulation in landfills to simulate temperatures at a southeastern landfill.

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.

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?

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.

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.

The overall objective of the proposed research is to develop an estimate of the mass of PFASs that are present in LFG and to begin to develop information the factors that impact their release. The proposed research will include measurements at full-scale landfills as well as measurements in lab scale reactors to understand trends in PFAS release during the decomposition cycle, the impact of waste age on PFAS concentrations and the impact of soil attenuation on PFAS release.

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.

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).

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 ???????????????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.