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Competitive Sorption And Transport Of Heavy Metals In Soil And Mn Oxide-Coated Sand, Joshua Tyler Padilla

LSU Doctoral Dissertations

This study investigated the competitive sorption of Ni, Pb, and Zn as well as synergistic interactions between Ni and phosphate (P) in soils and Mn oxide-coated sand. During stirred-flow experiments, the sorption of heavy metal cations by Olivier soil was mutually reduced when applied simultaneously. When applied consecutively, the cation of higher affinity was able to displace the cation of lower affinity from the soil surface, however, no evidence for the reverse case was observed. A novel general exchange kinetics model was able to correctly describe such displacement. Competition between Ni and Zn mutually increased mobility in Olivier and Windsor …

Investigation Of Sand-Biochar Mixtures As A Potential Roadway Fill Material, Katia J. Lele Lagmago

LSU Master's Theses

Biochar is a sustainable and lightweight carbon-rich material with a high surface area and porosity. Previous studies reported that biochar can reduce soil erosion and cracking, retain contaminants, and enhance soil aggregation. Given these favorable properties, soil-biochar mixtures have the possibility to serve as a multifunctional lightweight fill material for roadway embankment applications. The purpose of this research is to develop sand-biochar mixtures as a sustainable and multifunctional lightweight fill material for roadway embankment applications.

This research investigated the consolidation and hydraulic properties of sand-biochar mixtures by (1) performing 1D consolidation tests, (2) performing permeability tests, and (3) assessing the …

Soil Organic Matter Accretion, Complexity, And Degradation In Eroding Coastal Wetlands, Yadav Sapkota

LSU Doctoral Dissertations

Coastal wetlands are one of the most productive ecosystems on the earth. They are increasingly recognized and valued for atmospheric carbon sequestration and storage for a long time. However, coastal wetlands acreage is shrinking, across the globe, due to several factors including sea-level rise, local subsidence, edge erosion, extreme weather events, and anthropogenic activities. The coastal wetlands in the Mississippi River Deltaic Plain experience high relative sea-level rise, limited sediment supply, and high marsh edge erosion, leading to substantial land loss. These wetlands require restoration and conservation to slown down land loss and continue providing ecosystem services. The coastal restoration …

Initial Investigations Into Tools For Phytoremediation Of Lead From Urban And Suburban Landscapes, Michael Taylor Bryant

LSU Master's Theses

Lead is a pervasive and ongoing problem in the landscape, especially in urban and suburban areas where historic use of tetraethyl lead gasoline and leaded paint has increased background amounts to dangerous levels. One method to solve this problem is the use of hyperaccumulator plant species, capable of concentrating over 1000 ppm Pb into their tissues. This is a slow process, even with hyperaccumulators, so the use of amendments to improve Pb solubility has gained popularity, though with mixed results. This study examined Trachelospermum asiaticum, Ardisia japonica, and Ophiopogon japonicus, three common landscape groundcovers used in Louisiana, …

Water-Energy Nexus: Studies On Salinity Gradient Energy Harvest And Desalination, Guangcai Tan

LSU Doctoral Dissertations

Water and energy are fundamentally linked, and both are important for the development of human society. The demand for renewable energy and freshwater are two global challenges in the 21^st century. Herein, a novel chloride-ion (Cl⁻) concentration flow cell (CFC) based on two symmetrical electrodes (BiCl₃, CoCl₂, VCl₃, or BiOCl) separately by a cation-exchange membrane was used as an efficient method to recover salinity gradient (SG) energy. The CFC with metal chloride electrodes (BiCl₃, CoCl₂, and VCl₃) was based on Cl⁻ extraction/insertion, and that …

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 …

Effect Of Biosurfactant And Biochar On Ecosystem Functions And Oil Remediation In Crude Oil Contaminated Wetland Soils, Zhuo Wei

LSU Doctoral Dissertations

Decontamination of oil spill from coastal wetland soils requires a delicate approach. Remediation strategies using biochar, biosurfactant, and nutrient additions have been proposed. However, there is little information on application of these with combination for treatment of crude oil-contaminated wetland soil. Therefore, incubation studies were carried out to investigate the impact of biochar and rhamnolipid (RL) biosurfactant along with nitrogen (N) application on petroleum hydrocarbon degradation in a Louisiana coastal saline marsh and their impacts on greenhouse gas (GHG) emission. Additionally, the toxicity of crude oil as well as remediation materials on coastal wetland ecosystem were assessed at three levels: …

Using Poultry Litter Ash As A Fertilizer Source For Bermudagrass (Cynodon Dactylon) Establishment And Loblolly Pine (Pinus Taeda) Plantation, Crystal L. Vance

LSU Doctoral Dissertations

Lower solubility of P in poultry litter ash (PLA) than conventional phosphorus (P) fertilizers such as triple superphosphate (TSP) may reduce P losses in drainage and runoff; however, lower P solubility may reduce its efficacy as a P source. A laboratory experiment was conducted to examine the effect of acidity on P release and the effect of different combustion temperatures on P solubility as a prerequisite to the following studies. The first research objective was to determine the effect of soil pH on the efficiency of PLA relative to TSP for establishment of common bermudagrass (Cynodon dactylon L.) and …

Development Of A Tunable Platform For The Study Of Geomacromolecular Matrices Using Controlled Radical Polymerization, Arjun Pandey

LSU Doctoral Dissertations

Soil is an important environmental component, and the study of soil processes have many practical implications such as improvement in agriculture, mitigation of climate change etc. The widespread use of Agricultural Chemicals (ACs) in modern agriculture has resulted in adverse effects in environment and human health mostly through contamination into food and water sources. Study of fate, bioavailability, and transport of ACs involves molecular level understanding of their interactions with soil. This can be challenging due to complex and heterogeneous nature of soil. One common approach used is the correlation of macroscopic properties of soil, (e.g. sorption) with empirical parameters …

Silicon Fertilization In Rice And Wheat: Dynamics With Trace Elements And Effect Of Silicate Slag Granular Size On The Release Pattern Of Monosilicic Acid In Soil, Wooiklee S. Paye

LSU Doctoral Dissertations

Studies were conducted to evaluate the impact of silicon (Si) fertilization on the uptake of harmful trace elements in Louisiana rice production system, and document the effect of silicate slag granular size on its ability to supply Si in wheat. The influence of silicate slag and lime on the uptake and translocation of harmful trace elements in rice grain was determined. Results showed that both slag and lime had similar effects on pH at five of the nine sites investigated. Soil Si was significantly (P <0.001) increased with application of silicate slag at all sites. Lime and silicate slag had no effect on the concentration of trace elements in soil. However, increasing Si rates were negatively correlated with arsenic (As) and cadmium (Cd) concentration in rice grain. The release pattern of monosilicic acid (H₄SiO₄) from wollastonite and silicate slag was compared in a wheat greenhouse …

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 …

Effects Of Silicon And Beneficial Bacteria On Sheath Blight Of Rice And The Microbial Community Of Rice Rhizosphere, Jhonson Leonard

LSU Master's Theses

Sheath blight (ShB), caused by Rhizoctonia solani Kühn, is an economically important soil-borne disease of rice (Oryza sativa) that can cause up to 50 % yield losses. Application of fungicides is the most effective and commonly used method for managing sheath blight. However, the pathogen can develop new resistant strains upon continuous exposure to a fungicide. Moreover, the use of inorganic fungicides is not eco-friendly. The utilization biological control agents (BCAs) can be a more sustainable and safe means of managing ShB. To develop alternate strategies for ShB management, I am exploring the effect of the silicon (Si) …

Iron-Sulfur Cluster Biosynthesis In Methanogens, Cuiping Zhao

LSU Doctoral Dissertations

Methanogens live in a syntrophic consortium with bacteria, taking advantage of the metabolic abilities of their syntrophic partners to overcome energetic barriers and break down compounds that they cannot digest by themselves. Interspecies electron transfer, which is a major type of microbial communication in syntrophic processes, improves methanogenesis and anaerobic oxidization of methane (AOM) processes involved in syntrophic consortia. These processes have a significant impact on the global carbon cycle. Most of the essential enzymes involved in methanogenesis are iron-sulfur proteins. Iron-sulfur clusters are one of the oldest and most versatile cofactors present in all domains of life. To date, …

The Use Of Cellulose Nanofibers In Polymer Matrix Composites Via 3d Printing, Ju Dong

LSU Doctoral Dissertations

Filament fused fabrication (FFF) is an extrusion-based 3D printing technology for manufacturing thermoplastic polymers. A major obstacle of 3D printed thermoplastic is the limited crystallinity resulting from a fast quench while material leaving the hot nozzle and solidifying quickly at the low-temperature platform. As a result, the mechanical performances of 3D printed thermoplastic is normally inadequate in comparison with conventionally manufactured ones (e.g., from injection molding). In this work, we developed two strategies for reinforcing and functionalizing 3D printed thermoplastic composites using cellulose nanofibers (CNFs) as nanofillers. Firstly, L-lactide monomers were grafted onto CNFs via ring-opening polymerization. The synthesized poly(lactic …

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 …

The Effects Of Biochar And Nitrogen Stabilizers Application On Forage Crop Growth, Greenhouse Gas Emission And Soil Quality, Joseph Elias Rodrigues Mikhael

LSU Doctoral Dissertations

ABSTRACT

Forage systems are important for animal production. Nitrogen fertilization and herbicides use has led to a significant increase in forage production. Therefore, this study aimed to investigate the effects of biochar and N-(n-butyl) thiophosphoric triamide + dicyandiamide (NBPT+DCD) application on manure and urea fertilized soil by focusing on nitrogen fertilizer efficiency use, greenhouse gases emissions, microbial community, soil aggregate stability, and organic carbon functional groups. In addition, herbicides effect on greenhouse gases emission was assessed. Biochar and NBPT+DCD increased nitrogen use efficiency of both fertilizers managements and reduced the N₂O emissions following manure fertilization. However, NBPT+DCD was …

Glyphosate In Soils: Retention, Transport, And Effect Of Phosphate, Joshua Padilla

LSU Master's Theses

Glyphosate [N-(phosphonomethyl) glycine)] (GPS) is currently the most commonly used herbicide worldwide, and is generally considered as immobile in soils. However, numerous reports of the environmental occurrence of the herbicide coupled with recent evidence of human toxicity require further investigation as to the behavior of GPS in the soil environment. The objectives of this study were to quantify GPS sorption and mobility in two Louisiana agricultural soils with varying physiochemical properties; Commerce silt loam and Sharkey clay. Results of batch sorption studies indicated a high affinity of both soils for solvated GPS, with 24-hour Freundlich partitioning coefficients of 158 and …

Effect Of Increasing Levels Of Monosilicic Acid On Arsenic And Phosphorus Sorption In Soil, Flávia Bastos Agostinho

LSU Doctoral Dissertations

Arsenic (As) accumulation in rice (Oryza sativa) grains has increased human’s daily intake. Studies have shown that arsenite is taken up through known silicon (Si) transporters in rice. Moreover, the availability of As in soil is affected by chemically similar ligands that have high affinity to oxides surfaces, such as Si and phosphorus (P). Studies were conducted to: (I) investigate the role of elevated levels of Si on the concentration of different As fractions in soil and on As uptake by rice; (II) evaluate the effect of increasing monosilicic acidconcentrations on As sorption and kinetics in soil; and …

Effects Of Enhanced Efficiency Nitrogen Fertilizers On Agronomic Parameters And Loss Pathways In The Subtropical Mississippi Delta Region, Scott Michael Pensky

LSU Master's Theses

Minimizing nitrogen (N) loss is critical for improving N use efficiency (NUE) in crop production and reducing its effects on the environment. Management practices such as seasonal application timing of N fertilizers and the addition of enhanced efficiency N fertilizers (EENFs) were investigated for the high N requirement of the two most common cereal crops globally, corn (Zea mays L.) and wheat (Triticum aestivum L.), in the subtropical climate of Louisiana. Field research was established during the 2016 and 2017 seasons at the LSU Agricultural Center’s Dean Lee and Central research stations to examine the effect of different EENFs and …

Louisiana Agriculture Winter, 2018, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

Louisiana Agriculture Summer, 2017, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

Evaluation Of Biochar As A Feed Additive In Commercial Broiler Diets, Brandon Michael Cheron

LSU Master's Theses

Two experiments were conducted to evaluate sugarcane biochar as a feed ingredient in commercial broiler diets. Experiment 1 was conducted for 11 days using 300 male Ross 708 broilers. Broilers were allotted to one of five treatment diets containing 0%, 0.5%, 1.0%, 2%, or 4% biochar. Experiment 2 was conducted for 19 days using 450 male Ross 708 broilers. Chicks were allotted to one of 9 treatment diets containing 0%, 0.25%, 0.5%, 0.75%, 1%, 1.25%, 1.5%, 1.75% or 2% biochar. Broilers and feed were weighed at day 0 and 10 in experiment 1 and day 0, 10 and 18 in …

Soil Properties' Response To Wheat And Corn Stubble Residue Management In Louisiana, Autumn Danielle Acree

LSU Master's Theses

Crop residue plays an important role in improving soil fertility. Crop residue affects soil biological and chemical properties by increasing soil organic matter, nutrient status and availability, and microbial activity. The degree of the effects of crop residue on soil fertility depends on the crop residue management practice. Samples were collected in 2014 in wheat (Triticum spp.) stubble and corn (Zea mays) stubble residue. A second soil sample collection under wheat stubble residue was taken in 2015 in the prescribed fire and no-till sections. A total of 342 soil samples (0-2.5cm) were collected across conventional tillage, no-till, and prescribed fire …

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

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

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

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 …

Biomass Catalytic Upconversion With A Metallic Catalyst Bed Under Radio Frequency Induction Heating, Mohammad Abu-Laban

LSU Master's Theses

This study investigated the thermal performances of platinum particles when coupled on a steel support, under the application of a radio frequency (RF) field. Platinum nanoparticles were reduced on the surfaces of type-316 stainless steel balls, based on published methods of Pt reduction from chloroplatinic acid. Alternatively, 1wt. % Pt/Al2O3 commercial catalyst pellets were mixed with stainless steel balls and investigated for hydro-deoxygenation of pyrolysis oil from pine sawdust biomass. The catalysts were placed inside an electric insulator tube suspended within a looping copper coil connected to the induction heater, and heated at different power levels. An infrared camera was …

A Model Compound Study In Syngas Tar Reforming, Jaren Lee

LSU Master's Theses

Biomass or coal gasification are promising processes for renewable energy. However, a major operating problem in gasification is what to do with syngas byproducts such as H2S and tars (heavy hydrocarbons) that cause catalyst deactivation downstream. Studies have shown that rare earth oxides (REOs) doped with transition metals are promising catalysts for tar reforming in the presence of sulfur.(R. Li, Roy, Bridges, & Dooley, 2014) In Chapter 1, propane is studied as a model compound for tar reforming with transition metal-doped (e.g., Mn, Fe) REOs. These are compared to a typical commercial Ni/Al2O3 catalyst. The results showed that REO/TM catalysts …

Application Of Biomass Derived Materials In Nanocomposites And Drilling Fluids, Kunlin Song

LSU Doctoral Dissertations

Tar is inevitably produced from biomass thermochemical processes, and is often disposed as an industrial waste, leading to environmental pollution. As a result of its high carbon content, tar was expected to be a promising precursor for manufacturing carbon materials. Consequently, low-cost porous carbon nanofibers (CNFs) using tar, polyacrylonitrile (PAN), and silver nanoparticles was fabricated through electrospinning and subsequent stabilization and carbonization processes. The continuous electrospun nanofibers were obtained with diameters ranging from 392 to 903 nm. The addition of biomass tar resulted in increased fiber diameters, reduced thermal stabilities, and slowed cyclization reactions of PAN in the as-spun nanofibers. …