Civil and Environmental Engineering Commons^™

Exploring Soil Microbial Dynamics In Southern Appalachian Forests: A Systems Biology Approach To Prescribed Fire Impacts, Saad Abd Ar Rafie

Doctoral Dissertations

Prescribed fires in Southern Appalachian forests are vital in ecosystem management and wildfire risk mitigation. However, understanding the intricate dynamics between these fires, soil microbial communities, and overall ecosystem health remains challenging. This dissertation addresses this knowledge gap by exploring selected aspects of this complex relationship across three interconnected chapters.

The first chapter investigates the immediate effects of prescribed fires on soil microbial communities. It reveals subtle shifts in porewater chemistry and significant increases in microbial species richness. These findings offer valuable insights into the interplay between soil properties and microbial responses during the early stages following a prescribed fire. …

A Bug’S Life: Integration Of Anaerobic Digestion And Bioelectrochemical Systems For Enhanced Energy Recovery From Wastewater Solids And Other Waste Substrates, Jeff Ryan Beegle

Masters Theses

Organic waste streams, like domestic wastewater and municipal solid waste, have the potential to be used as feedstocks for biotechnology processes to produce high value products and energy. This thesis investigated the technological, economical, and environmental potential for integrated anaerobic digestion (AD) and bioelectrochemical system (BES) platforms as they were theoretically and physically evaluated for energy recovery from domestic wastewater. The first chapter of this thesis compared the theoretical energy efficiencies of converting waste directly into electricity, using AD and BES alone and in various combinations. This chapter reviewed the experimentally demonstrated energy efficiencies reported in the literature with comparisons …

Ecology Of Organohalide-Respiring Dehalococcoides Mccartyi: Corrinoid Cofactor-Related Community Interactions And Controls Over Strain Selection, Burcu Şimşir

Doctoral Dissertations

Organohalides such as tetrachloroethene (PCE) and trichloroethene (TCE) are among the most prevalent toxic groundwater contaminants. Remediation of organohalide-contaminated sites has high priority, and efficient and cost-effective remedies are needed to prevent environment and human exposure through contaminated water. Bacterial organohalide-respiration plays a major role in organohalide detoxification. Dehalococcoides mccartyi (Dhc) are key mediators in bioremediation, since only Dhc strains have been documented in complete detoxification of chlorinated ethenes to benign ethene. Dhc depends on other microorganisms in the environment for essential growth requirements (e.g., hydrogen and vitamins). For successful implementation of the reductive dechlorination to remediate contaminated …

Bioremediation Of Chlorinated Ethenes: Ph Effects, Novel Dechlorinators And Decision-Making Tools, Yi Yang

Doctoral Dissertations

Chlorinated solvents have been widely used in different areas of modern society. Usage of these chlorinated solvents was not necessarily accompanied with proper handling and disposal of these hazardous compounds, which caused a variety of environmental problems and continues to affect human health. Remediation of chlorinated ethenes contaminated sites has high priority for state regulators and site owners. Among the available treatment technologies, bioremediation shows great promise as a cost-effective corrective strategy for a variety of environmental pollutants. Prerequisites are that the microbiology involved in contaminant degradation and geochemical factors, such as pH, are understood, so that bioremediation technologies can …

Isolation And Characterization Of Microbial Communities From Hydraulic Fracturing Fluids, Sheridan S. Brewer 6284984

Chancellor’s Honors Program Projects

No abstract provided.

Removal Of Trace Organic Compounds In Domestic Wastewater Using Recirculating Packed-Bed Media Filters, Brittani Nikole Perez

Masters Theses

Pharmaceuticals and personal care products (PPCPs) are commonly detected in the environment resulting from their survival from conventional wastewater treatment systems. More information is needed about the fate and transfer of these trace organic compounds in domestic wastewater and their associated risks so that efficient strategies for their removal can be developed for both large/small scale treatment systems. This study aimed to determine whether onsite wastewater treatment systems were capable of providing PPCP removal, in addition to quantifying different forms of removal (biodegradation/sorption). A column study was constructed to determine the removal efficiencies of 3 target PPCPs, endocrine disrupting compound …

Design Of An Underwater Video And Gps Mapping System For The Exploration Of Streambed Aquatic Populations, William Barbour

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

This design project was initiated due to the need for an underwater video mapping system optimized for exploration along the streambed or riverbed and under rocks. Such a system would be used for population mapping of fish and other aquatic species. The system also needed to incorporate global positioning system data with the visual data. The current prototype successfully fulfills the requirements for underwater practicality and visual and GPS data collection. It incorporates a compact waterproof camera with Sony lens, two Fenix high-intensity waterproof flashlights for illumination, a handheld DVR for recording video, and a Garmin 60CSx GPS unit. The …

Exploring Anaerobic Reductive Dechlorination At Low Ph Environments, Yi Yang

Masters Theses

Chlorinated aliphatic hydrocarbons (CAHs), such as tetrachloroethene (PCE) and trichloroethene (TCE), are ubiquitously pollutants in aquifer sediments and groundwater due to their heavy usage in industry and inappropriate disposal in the last century. Among about 1300 NPL (National Priorities List) sites, PCE and TCE are the two most frequently detected hazardous contaminants.

Engineered bioremediation, including biostimulation and bioaugmentation, is a promising technology to clean those PCE and/or TCE contaminated sites. However, in many contaminated groundwater systems and hazardous waste sites, pH can be lower than 5 to 6. And release of HCl (strong acid) from anaerobic reductive dechlorination may lower …

Physiological Stress In Native Brook Trout (Salvelinus Fontinalis) During Episodic Acidification Of Streams In The Great Smoky Mountains National Park, Keil Jason Neff

Masters Theses

Episodes of stream acidification are suspected to be the primary cause of the extirpation of native southern brook trout (Salvelinus fontinalis) from six headwater streams in the Great Smoky Mountains National Park (GRSM). During periods of increased flow from storm events, stream pH can drop below 5.0 (minimum of 4.0) for 2-days or longer. To provide evidence that native brook trout are impacted by stream acidification, in situ bioassay experiments were conducted. Changes in stream water chemistry and brook trout physiology were determined during a 36-hour acidic episode at three remote headwater stream sites in the Middle Prong of the …