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Xylan Fast Pyrolysis: An Experimental And Modelling Study Of Particle Changes And Volatiles Release, F Cerciello, E Freisewinkel, A Coppola, C Ontyd, D Tarlinski, Martin Schiemann, Osvalda Senneca, Pierro Salatino, C Allouis, Victor Scherer, Thomas H. Fletcher Jan 2024

Xylan Fast Pyrolysis: An Experimental And Modelling Study Of Particle Changes And Volatiles Release, F Cerciello, E Freisewinkel, A Coppola, C Ontyd, D Tarlinski, Martin Schiemann, Osvalda Senneca, Pierro Salatino, C Allouis, Victor Scherer, Thomas H. Fletcher

Faculty Publications

Biomass char particles produced by pyrolysis may have different morphologies, which has important implications on burning mode, conversion rate and boiler efficiency. These features are difficult to address due to the complexity of biomass structure and pyrolysis reaction models. The present work reports preliminary results on the morphological changes and volatile release that solid particles of Xylan experience upon fast heating in a Drop Tube Reactor (DTR) and in a Heated Strip Reactor (HSR) in a range of temperature between 1100 and 1573 K under inert atmosphere with heating rate in the order of 103 K/s. Two different Xylan …


Fate And Transport Of Per- And Polyfluoroalkyl Substances (Pfas) At Aqueous Film Forming Foam (Afff) Discharge Sites: A Review, Jeffery T. Mcgarr, Eric G. Mbonimpa, Drew C. Mcavoy, Mohamad R. Soltanian May 2023

Fate And Transport Of Per- And Polyfluoroalkyl Substances (Pfas) At Aqueous Film Forming Foam (Afff) Discharge Sites: A Review, Jeffery T. Mcgarr, Eric G. Mbonimpa, Drew C. Mcavoy, Mohamad R. Soltanian

Faculty Publications

Per- and polyfluorinated alkyl substances (PFAS) are an environmentally persistent group of chemicals that can pose an imminent threat to human health through groundwater and surface water contamination. In this review, we evaluate the subsurface behavior of a variety of PFAS chemicals with a focus on aqueous film forming foam (AFFF) discharge sites. AFFF is the primary PFAS contamination risk at sites such as airports and military bases due to use as a fire extinguisher. Understanding the fate and transport of PFAS in the subsurface environment is a multifaceted issue. This review focuses on the role of adsorbent, adsorbate, and …


Artificial Neural Networks And Gradient Boosted Machines Used For Regression To Evaluate Gasification Processes: A Review, Owen Sedej, Eric Mbonimpa, Trevor Sleight, Jeremy M. Slagley Aug 2022

Artificial Neural Networks And Gradient Boosted Machines Used For Regression To Evaluate Gasification Processes: A Review, Owen Sedej, Eric Mbonimpa, Trevor Sleight, Jeremy M. Slagley

Faculty Publications

Waste-to-Energy technologies have the potential to dramatically improve both the natural and human environment. One type of waste-to-energy technology that has been successful is gasification. There are numerous types of gasification processes and in order to drive understanding and the optimization of these systems, traditional approaches like computational fluid dynamics software have been utilized to model these systems. The modern advent of machine learning models has allowed for accurate and computationally efficient predictions for gasification systems that are informed by numerous experimental and numerical solutions. Two types of machine learning models that have been widely used to solve for quantitative …


Wetland Construction, Restoration, And Integration: A Comparative Review, Douglas J. Spieles Jan 2022

Wetland Construction, Restoration, And Integration: A Comparative Review, Douglas J. Spieles

Faculty Publications

No abstract provided.


Environmentally Persistent Free Radicals As Sources Of Pops, Eric P. Vejerano, Jeonghyeon Ahn, Junaid Latif, Mustafa Mamun May 2021

Environmentally Persistent Free Radicals As Sources Of Pops, Eric P. Vejerano, Jeonghyeon Ahn, Junaid Latif, Mustafa Mamun

Faculty Publications

Environmentally persistent free radicals (EPFRs) are a new class organic pollutant sharing some of the attributes of persistent organic pollutants (POPs). This opinion/short review aims to describe the properties of EPFRs that merit their recognition as an additional and potentially significant source of POPs. EPFRs are ubiquitous in diverse environments because of multiple factors: (1) organic precursors from anthropogenic, biogenic, and other natural emission sources are abundant; multiple mechanisms in PM and soils form (2) EPFRs; and (3) EPFRs are stable and persist for a long time, thereby, accumulate in the environment and potentially transported long range. The hazards of …


Restoring Pre-Industrial Co2 Levels While Achieving Sustainable Development Goals, Mark E. Capron, Jim R. Stewart, Antoine De Ramon N’Yeurt, Michael D. Chambers, Jang K. Kim, Charles Yarish, Anthony T. Jones, Reginald B. Blaylock, Scott C. James, Rae Fuhrman, Martin T. Sherman, Don Piper, Graham Harris, Mohammed A. Hasan Sep 2020

Restoring Pre-Industrial Co2 Levels While Achieving Sustainable Development Goals, Mark E. Capron, Jim R. Stewart, Antoine De Ramon N’Yeurt, Michael D. Chambers, Jang K. Kim, Charles Yarish, Anthony T. Jones, Reginald B. Blaylock, Scott C. James, Rae Fuhrman, Martin T. Sherman, Don Piper, Graham Harris, Mohammed A. Hasan

Faculty Publications

© 2020 by the authors. Unless humanity achieves United Nations Sustainable Development Goals (SDGs) by 2030 and restores the relatively stable climate of pre-industrial CO2 levels (as early as 2140), species extinctions, starvation, drought/floods, and violence will exacerbate mass migrations. This paper presents conceptual designs and techno-economic analyses to calculate sustainable limits for growing high-protein seafood and macroalgae-for-biofuel. We review the availability of wet solid waste and outline the mass balance of carbon and plant nutrients passing through a hydrothermal liquefaction process. The paper reviews the availability of dry solid waste and dry biomass for bioenergy with CO2 …


A Review Of Coal Heating Value Correlations With Application To Coal Char, Tar, And Other Fuels, Andrew P. Richards, Denver Haycock, Jacob F. Frandsen, Thomas H. Fletcher Aug 2020

A Review Of Coal Heating Value Correlations With Application To Coal Char, Tar, And Other Fuels, Andrew P. Richards, Denver Haycock, Jacob F. Frandsen, Thomas H. Fletcher

Faculty Publications

Accurately measuring a fuel’s heating value is one of the first steps in the classification of a new fuel. Heating values are widely used in coal combustion research and are becoming more useful in other fuel types as well. Many different empirical correlations to predict heating values based on primary organic (CHONS) elemental composition are found in the literature, many of which were originally created to predict heating values of parent coal, and some of which have been extended for biomass. However, no correlations exist for heating values of coal chars and tars. Thirteen literature heating value correlations (10 model …


Controllable And Scalable Engineered Soil Surrogates Utilizing Simulated Soil Organic Matter For The Study Of Environmental, Ecological, And Agricultural Processes, Arjun Pandey, Benjamin J. Haywood, Ghada Abdalla, Stephen Smith, Balamurugan Subramanian, David A. Spivak, Robert L. Cook Jun 2020

Controllable And Scalable Engineered Soil Surrogates Utilizing Simulated Soil Organic Matter For The Study Of Environmental, Ecological, And Agricultural Processes, Arjun Pandey, Benjamin J. Haywood, Ghada Abdalla, Stephen Smith, Balamurugan Subramanian, David A. Spivak, Robert L. Cook

Faculty Publications

Copyright © 2020 American Chemical Society. An entirely new, tunable, and scalable platform (model) approach for the detailed study of important molecular processes that take place in geomacromolecular matrices, such as soils, using block copolymer materials at inorganic interfaces has been developed and applied to gain a molecular-level understanding of environmental pollutant/soil interactions. This approach provides a scalable platform with molecular-level control of the soil organic matter (SOM) chemical composition and structure, allowing one to examine proposed SOM interactions with agricultural chemicals (ACs). Accordingly, a series of engineered soil surrogates (ESSs) utilizing simulated SOM was synthesized, in which multiblock oligomers …


Comparison Of Pyrolysis Of Live Wildland Fuels Heated By Radiation Vs. Convection, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher Jan 2020

Comparison Of Pyrolysis Of Live Wildland Fuels Heated By Radiation Vs. Convection, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher

Faculty Publications

During wildland fires, which include both planned (prescribed fire) and unplanned (wildfire) fires, live and dead plants may be subject to both radiative and convective heat transfer mechanisms. In this study, the pyrolysis of 14 live plant species native to the forests of the southern United States was investigated using a flat-flame burner (FFB) apparatus under three heating modes in order to mimic pyrolysis of plants during wildland fires. The heating modes were: (1) radiation-only, where the plants were pyrolyzed under a moderate heating rate of 4 °C s−1 (radiative flux of 50 kW m−2); (2) convection-only, where the FFB …


Preparation Of Activated Biochar-Supported Magnetite Composite For Adsorption Of Polychlorinated Phenols From Aqueous Solutions, Byung-Moon Jun, Yejin Kim, Jonghun Han, Yeomin Yoon, Chang Min Park Sep 2019

Preparation Of Activated Biochar-Supported Magnetite Composite For Adsorption Of Polychlorinated Phenols From Aqueous Solutions, Byung-Moon Jun, Yejin Kim, Jonghun Han, Yeomin Yoon, Chang Min Park

Faculty Publications

For this study, we applied activated biochar (AB) and its composition with magnetite (AB-Fe3O4) as adsorbents for the removal of polychlorophenols in model wastewater. We comprehensively characterized these adsorbents and performed adsorption tests under several experimental parameters. Using FTIR, we confirmed successful synthesis of AB-Fe3O4 composite through cetrimonium bromide surfactant. We conducted adsorption tests using AB and AB-Fe3O4 to treat model wastewater containing polychlorophenols, such as 2,3,4,6-Tetrachlorophenol (TeCP), 2,4,6-Trichlorophenol (TCP), and 2,4-Dichlorophenol (DCP). Results of the isotherm and the kinetic experiments were well adapted to Freundlich’s isotherm model and the …


Implications Of Poultry Litter Usage For Electricity Production, Qiuzhou Ma, Krishna P. Paudel, Doleswar Bhandari, Chandra Theegala, Molly Cisneros Jul 2019

Implications Of Poultry Litter Usage For Electricity Production, Qiuzhou Ma, Krishna P. Paudel, Doleswar Bhandari, Chandra Theegala, Molly Cisneros

Faculty Publications

© 2019 Elsevier Ltd Poultry litter has the potential to cause water quality problems if it is not applied properly to the land as a crop nutrient. Based on the data available from a survey of Louisiana poultry producers, we find that it is not cost effective to transport poultry litter farther than 38.6 km from the production facilities for crop nutrient purposes. This limited breakeven distance restricts the movement of poultry litter and points to a need to identify an alternative disposal method. We review common methods of producing electricity from poultry litter. We identify the minimum cost solution …


Heating Rate And Temperature Effects On Pyrolysis Products From Live Wildland Fuels, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher Jan 2019

Heating Rate And Temperature Effects On Pyrolysis Products From Live Wildland Fuels, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher

Faculty Publications

Wildland fire, which includes both planned (prescribed fire) and unplanned (wildfire) fires, is an important component of many ecosystems. During wildland fires, low heating rate pyrolysis (slow pyrolysis) occurs during preheating and/or smoldering of plant material. High heating rate pyrolysis (fast pyrolysis) exists in the flame region. Pyrolysis temperature and heating rate play important roles on the yields and the compositions of pyrolysis products. In this work, the effects of pyrolysis temperature and heating rate on the yields and the compositions of pyrolysis products from 14 plant species native to the forests of the southern United States are shown. The …


Particulate Matter Containing Environmentally Persistent Free Radicals Induces Ahrdependent Cytokine And Reactive Oxygen Species Production In Human Bronchial Epithelial Cells, Ashlyn C. Harmon, Valeria Y. Hebert, Stephania A. Cormier, Balamurugan Subramanian, James R. Reed, Wayne L. Backes, Tammy R. Dugas Oct 2018

Particulate Matter Containing Environmentally Persistent Free Radicals Induces Ahrdependent Cytokine And Reactive Oxygen Species Production In Human Bronchial Epithelial Cells, Ashlyn C. Harmon, Valeria Y. Hebert, Stephania A. Cormier, Balamurugan Subramanian, James R. Reed, Wayne L. Backes, Tammy R. Dugas

Faculty Publications

© 2018 Harmon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Particulate matter (PM) is emitted during the combustion of fuels and wastes. PM exposure exacerbates pulmonary diseases, and the mechanism may involve oxidative stress. At lower combustion temperatures such as occurs in the cool zone of a flame, aromatic compounds chemisorb to the surface of metal-oxide-containing PM, resulting in the formation of surface-stabilized environmentally persistent free radicals (EPFR). Prior studies showed …


Removal Of Total Dissolved Solids From Reverse Osmosis Concentrates From A Municipal Wastewater Reclamation Plant By Aerobic Granular Sludge, Do-Hyung Kim, Sangjin Park, Yeomin Yoon, Chang Min Park Jul 2018

Removal Of Total Dissolved Solids From Reverse Osmosis Concentrates From A Municipal Wastewater Reclamation Plant By Aerobic Granular Sludge, Do-Hyung Kim, Sangjin Park, Yeomin Yoon, Chang Min Park

Faculty Publications

Reverse osmosis (RO) has been widely utilized in water reclamation plants and produces a concentrated brine (or reject) stream as a by-product. RO concentrates (ROC) contain vast quantities of salts and dissolved organic matter, such as biomass and humic-like substances, which hinder biological wastewater treatment (such as biological nitrogen removal). In this study, we cultivated granular sludge in an aerobic sequencing batch reactor to treat municipal wastewater with an organic loading rate of 2.1–4.3 kgCOD/m3 day at room temperature (25 °C), and remove total dissolved solids (TDS) from ROC by biosorption, with aerobic granular sludge as a novel biosorbent. …


Comparison Of Permanganate-Oxidizable Carbon And Mineralizable Carbon For Assessment Of Organic Matter Stabilization And Mineralization, Tunsisa T. Hurisso, Steve W. Culman, William R. Horwath, Jordon Wade, Deandra Cass, Joshua W. Beniston, Timothy M. Bowles, A. Stuart Grandy, Alan J. Franzluebbers, Meagan E. Schipanski, Shawn T. Lucas, Carmen M. Ugarte Sep 2016

Comparison Of Permanganate-Oxidizable Carbon And Mineralizable Carbon For Assessment Of Organic Matter Stabilization And Mineralization, Tunsisa T. Hurisso, Steve W. Culman, William R. Horwath, Jordon Wade, Deandra Cass, Joshua W. Beniston, Timothy M. Bowles, A. Stuart Grandy, Alan J. Franzluebbers, Meagan E. Schipanski, Shawn T. Lucas, Carmen M. Ugarte

Faculty Publications

Permanganate-oxidizable C (POXC) and mineralizable C (as determined by short-term aerobic incubation of rewetted soil) are measures of active organic matter that may provide early indication of soil C stabilization and mineralization processes. To date, the relationship between these two promising active organic matter tests has not been comprehensively evaluated, and little is known about their functional role in the soil ecosystem. Here, we examined the relationship between POXC and mineralizable C across a wide range of soil types, management histories, and geographic locations across the United States (13 studies, 76 total sites; n = 1071) and the ability of …


Addressing Emerging Risks: Scientific And Regulatory Challenges Associated With Environmentally Persistent Free Radicals, Tammy R. Dugas, Slawomir Lomnicki, Stephania A. Cormier, Barry Dellinger, Margaret Reams Jun 2016

Addressing Emerging Risks: Scientific And Regulatory Challenges Associated With Environmentally Persistent Free Radicals, Tammy R. Dugas, Slawomir Lomnicki, Stephania A. Cormier, Barry Dellinger, Margaret Reams

Faculty Publications

© 2016 by the authors; licensee MDPI, Basel, Switzerland. Airborne fine and ultrafine particulate matter (PM) are often generated through widely-used thermal processes such as the combustion of fuels or the thermal decomposition of waste. Residents near Superfund sites are exposed to PM through the inhalation of windblown dust, ingestion of soil and sediments, and inhalation of emissions from the on-site thermal treatment of contaminated soils. Epidemiological evidence supports a link between exposure to airborne PM and an increased risk of cardiovascular and pulmonary diseases. It is well-known that during combustion processes, incomplete combustion can lead to the production of …


Model System Study Of Environmentally Persistent Free Radicals Formation In A Semiconducting Polymer Modified Copper Clay System At Ambient Temperature, Ugwumsinachi G. Nwosu, Lavrent Khachatryan, Sang Gil Youm, Amitava Roy, Albert Leo N. Dela Cruz, Evgueni E. Nesterov, Barry Dellinger, Robert L. Cook Jan 2016

Model System Study Of Environmentally Persistent Free Radicals Formation In A Semiconducting Polymer Modified Copper Clay System At Ambient Temperature, Ugwumsinachi G. Nwosu, Lavrent Khachatryan, Sang Gil Youm, Amitava Roy, Albert Leo N. Dela Cruz, Evgueni E. Nesterov, Barry Dellinger, Robert L. Cook

Faculty Publications

© The Royal Society of Chemistry 2016. This paper systematically investigates how environmentally persistent free radicals (EPFRs) are formed in a phenol contaminated model soil. Poly-p-phenylene (PPP) modified and copper-loaded montmorillonite (MMT) clays were developed and used as models of soil organic matter and the clay mineral component, respectively, with phenol being employed as a precursor pollutant. The polymer modification of the clays was carried out via surface-confined Kumada catalyst-transfer chain-growth polymerization. The presence and location of the polymer were confirmed by a combination of thermogravimetric analysis (TGA), Raman spectroscopy, and X-ray diffraction data. EPFRs were formed by the Cu(ii)-clay …


Model System Study Of Environmentally Persistent Free Radicals Formation In A Semiconducting Polymer Modified Copper Clay System At Ambient Temperature, Ugwumsinachi G. Nwosu, Lavrent Khachatryan, Sang Gil Youm, Amitava Roy, Albert Leo N. Dela Cruz, Evgueni E. Nesterov, Barry Dellinger, Robert L. Cook Jan 2016

Model System Study Of Environmentally Persistent Free Radicals Formation In A Semiconducting Polymer Modified Copper Clay System At Ambient Temperature, Ugwumsinachi G. Nwosu, Lavrent Khachatryan, Sang Gil Youm, Amitava Roy, Albert Leo N. Dela Cruz, Evgueni E. Nesterov, Barry Dellinger, Robert L. Cook

Faculty Publications

This paper systematically investigates how environmentally persistent free radicals (EPFRs) are formed in a phenol contaminated model soil. Poly-p-phenylene (PPP) modified and copper-loaded montmorillonite (MMT) clays were developed and used as models of soil organic matter and the clay mineral component, respectively, with phenol being employed as a precursor pollutant. The polymer modification of the clays was carried out via surface-confined Kumada catalyst-transfer chain-growth polymerization. The presence and location of the polymer were confirmed by a combination of thermogravimetric analysis (TGA), Raman spectroscopy, and X-ray diffraction data. EPFRs were formed by the Cu(ii)-clay (Cu(ii)CaMMT) and poly-p-phenylene-Cu(ii)clay (PPP-Cu(ii)CaMMT) composite systems under …


Model System Study Of Environmentally Persistent Free Radicals Formation In A Semiconducting Polymer Modified Copper Clay System At Ambient Temperature, Ugwumsinachi G. Nwosu, Lavrent Khachatryan, Sang Gil Youm, Amitava Roy, Albert Leo N. Dela Cruz, Evgueni E. Nesterov, Barry Dellinger, Robert L. Cook Jan 2016

Model System Study Of Environmentally Persistent Free Radicals Formation In A Semiconducting Polymer Modified Copper Clay System At Ambient Temperature, Ugwumsinachi G. Nwosu, Lavrent Khachatryan, Sang Gil Youm, Amitava Roy, Albert Leo N. Dela Cruz, Evgueni E. Nesterov, Barry Dellinger, Robert L. Cook

Faculty Publications

This paper systematically investigates how environmentally persistent free radicals (EPFRs) are formed in a phenol contaminated model soil. Poly-p-phenylene (PPP) modified and copper-loaded montmorillonite (MMT) clays were developed and used as models of soil organic matter and the clay mineral component, respectively, with phenol being employed as a precursor pollutant. The polymer modification of the clays was carried out via surface-confined Kumada catalyst-transfer chain-growth polymerization. The presence and location of the polymer were confirmed by a combination of thermogravimetric analysis (TGA), Raman spectroscopy, and X-ray diffraction data. EPFRs were formed by the Cu(ii)-clay (Cu(ii)CaMMT) and poly-p-phenylene-Cu(ii)clay (PPP-Cu(ii)CaMMT) composite systems under …


Biochar Amendment Of Grassland Soil May Promote Woody Encroachment By Eastern Red Cedar, Ramesh Laungani, Kenneth Elgersma, Maria Juarez, Kristin Mcelligott, Tyler Kuhfahl Jan 2016

Biochar Amendment Of Grassland Soil May Promote Woody Encroachment By Eastern Red Cedar, Ramesh Laungani, Kenneth Elgersma, Maria Juarez, Kristin Mcelligott, Tyler Kuhfahl

Faculty Publications

Although carbon (C) additions to soil have been used in restoration to combat invasive species through changes in soil nitrogen (N) availability, carbon amendments to soil derived from plant material can impact soil N availability in a species-specific manner. As such, amendment-driven feedbacks on N may impact invasive species success and woody encroachment. Soil amendments like biochar, which is often added to soil to increase C storage in grassland systems, may unintentionally encourage woody encroachment into these grasslands by changing soil N dynamics. Few studies have examined biochar impacts on non-agricultural species, particularly invasive species. Woody encroachment of Eastern Red …