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. …

Evaluation Of Powdered Activated Carbon For Control Of Taste And Odors Caused By Geosmin, Anthony Joe Rodriguez

Open Access Theses & Dissertations

The primary sources of taste and odor problems associated with surface water supplies spawn from algae and bacterial blooms that secrete odorous chemicals such as Geosmin and MIB. These musty, odorous, organic compounds are usually detectable by the human nose at concentrations of 5 to 10 ppt and can create considerable concern by consumers that can lead to complaints and misconceptions of odors as a water quality problem. Typically, since chemical or ozone treatment can be costly, activated carbon (powdered or granular) is generally employed in the process of removing organic compounds, such as Geosmin and MIB. The research presented …

Numerical Modeling And Isotope Tracers To Investigate Karst Biogeochemistry And Transport Processes, Admin Husic

Theses and Dissertations--Civil Engineering

This dissertation investigated the physical and biogeochemical processes affecting the source, fate, and transport of sediment, carbon, and nitrogen within a highly-coupled fluviokarst system. Elemental and isotopic datasets were collected at surface and subsurface locations for both dissolved and particulate contaminant phases, new methodology regarding data collection was presented to the karst research community, an in-cave sediment transport model coupling physical transport with elemental and isotopic mass balances of carbon and nitrogen was formulated, pathway and process control on nitrate leaching from agricultural karst watersheds was assessed, and nitrate mobilization and fractionation were modeled using high frequency storm sampling and …

Sizing An Anaerobic Digester In A Rural Developing World Community: Does Household Fuel Demand Match Greenhouse Gas Production?, Ronald Keelan Greenwade

USF Tampa Graduate Theses and Dissertations

Anaerobic digestion is the process by which organic carbon is converted into biogas in the form of carbon dioxide (CO₂) and methane (CH₄). Both of these products are greenhouse gases that contribute to global warming. Therefore if anaerobic reactors are improperly maintained and biogas is leaked or intentionally released into the atmosphere because biogas production exceeds household demand, these reactors may become generators of greenhouse gas emissions instead of sustainable energy producers. The objective of this research was to develop a framework to assess if the demand for biogas by a rural adopter of an anaerobic …

The Use Of Cod, Toc, Fluorescence, And Absorbance Spectroscopy To Estimate Biochemical Oxygen Demand In Wastewater, Evelyn Aramaine Christian

UNLV Theses, Dissertations, Professional Papers, and Capstones

All wastewater treatment facilities must obtain a National Pollution Discharge Elimination System (NPDES) permit, which regulates the quality of water that is discharged. Common to all NPDES permits is a limit on organic matter, as determined by the five-day biochemical oxygen demand (BOD5) test. More rapid methods, such as chemical oxygen demand (COD), total organic carbon (TOC), fluorescence, and absorbance spectroscopy are also capable of quantifying organic matter. Previous studies indicate it is possible to develop correlations between these parameters. This study explored the correlations using influent, primary clarifier effluent, and finished effluent samples from an operational wastewater treatment plant …

Investigating The Physical Properties And Runoff Treatment Capability Of Pervious Concrete Containing Granular Activated Carbon, Mark Elias Elkouz

UNLV Theses, Dissertations, Professional Papers, and Capstones

A current environmental concern is that of urban stormwater runoff, which can carry a multitude of contaminants and could threaten or impair surface waters. Pervious concrete (PC) is a type of concrete with significant void spaces that can facilitate infiltration and lead to less runoff. The EPA cites previous research to show that pervious pavement structures reduce such contaminants as metals and total suspended solids. Since Granular Activated Carbon (GAC) is a well-known contaminant adsorbent, the purpose of this research was to determine if PC with added GAC would result in improved runoff treatment, while still maintaining its material properties. …

Development Of An Integrated Process Model For Algae Growth In A Photobioreactor, Mehregan Jalalizadeh

USF Tampa Graduate Theses and Dissertations

While understanding the kinetics of algae growth plays an important role in improving algae cultivation technology, none of the existing kinetic models are able to describe algae growth when more than three growth limiting factors are involved. A model was developed in this study to describe algae growth in a photobioreactor. Two expressions were proposed based on the Monod model to relate the specific growth rate of algae to the concentration of nitrogen, phosphorus, inorganic carbon and light intensity in the culture media. Algal biomass concentration as a function of time was calculated by solving mass and energy balances around …

Determination Of Freshwater Algal Biomass And Sulfolipid Content As Functions Of Inorganic Carbon Treatment, Melissa Morella

All Theses

Cultures of mixed freshwater algae were grown in open batch reactors made up of modified BG-11 media that contained 0, 25, 50 or 100% of the suggested inorganic carbon content (0, 0.5, 0.1 and 0.2 g/L Na₂CO₃) to assess the subsequent production of the high-value product, sulfoquinovosyl diacylglycerol (SQDG). After 25 days of growth, the reactors were composed of primarily Oscillatoria growth. All four reactors exhibited a trend of increasing biomass and alkalinity with time, and an initial increase then decrease in pH. The total inorganic carbon (TIC) in all reactors exhibited a mirrored, opposite trend …

Effect Of Inorganic Salts On Adsorption Process, Pai-Yuan Horng

Dissertations

`Small amounts (0.0 M-0.01 M) of inorganic salts (sodium chloride, calcium chloride, and aluminum chloride) added to bituminous coal fly ash and granular activated carbon in batch adsorption treatment experiments indicates the possibility of enhancing the extent and rate of adsorption process.

Experiments were conducted on aqueous solutions of highly toxic and hazardous chemicals, those include : phenol, benzene, toluene, isopropyl alcohol, and methyl-isobutyl ketone. Single and multiple solute systems were examined separately. Removal of organic pollutants was measured using a Flame Ionization Detector Gas Chromatograph.

This study investigated the role of inorganic salts during the sorption process. The results …

An Isothermal Study Of An S.A.E. 6150 Steel, Tom Liss, C. Arentzen

Bachelors Theses and Reports, 1928 - 1970

The purpose of this thesis is to set forth the method followed, the laboratory procedure practiced, the results obtained, the conclu­sions drawn, and the recommendations proposed as a consequence of a metallographic study of the isothermal transformation of an S.A.E. 6150 steel.

The Casting Of Anodes For The Series System Of Electrolytic Copper Refining, Robert R. Kupfer

Bachelors Theses and Reports, 1928 - 1970

The electrolytic refining process, while usually considered an auxiliary process used in conjunction with pyrometallurgical extraction, deserves a special niche in the complex metallurgy of copper. The development of electrolytic copper refining, for example, is largely responsible for the prominence of the electrical industry. Conversely, it could be stated that the electrical industry played an important part in the development of the copper industry.

Chromizing Of Steels, Edward Buchanan

Bachelors Theses and Reports, 1928 - 1970

In recent years, considerable thought and study have been given to the use of chromized articles in place of chromium stainless steel articles. The present extensive application of chromizing, indeed, helps greatly to conserve this valuable metal.

An Investigation Of A Particular Weldment Failure, Byron Clow

Bachelors Theses and Reports, 1928 - 1970

Two sets of weld-test coupons, supposedly made under identical conditions, were submitted to this institution last year for approval and certification under the A.S.M.E. Welder's Qualification Code. The first set of coupons was unsatisfactory. The second set, made by the same operators one month later, was satisfactory.

The Leaching Of Electrodeposition Of Iron, Emmett G. Simmons

Bachelors Theses and Reports, 1928 - 1970

Electrolytic iron as deposited is brittle and therefore must be annealed. After annealing, the material is ductile and closely resembles copper in its behavior under work. It is claimed to be more resistant to corrosion than dead soft iron. It also has the advantage of corroding uniformly ( or­dinary soft iron develops pin holes which shorten its life considerably).

The extreme purity of electrolytic iron namely makes it very suitable as a base metal for alloys. Its ductility opens up a field for use in the manufacture of cold rolled strip, seamless tubes, and wire.