Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Academic (1)
- Adsorption (1)
- Aerosol (1)
- Ammonia (1)
- Application (1)
-
- Arsenic (1)
- BMP (1)
- Bangladesh groundwater (1)
- Biodegradation (1)
- Bioelectrochemical (1)
- CO2 utilization (1)
- CWTS (1)
- Calcium carbonate (1)
- Calcium silicate (1)
- Cellulosic ethanol (1)
- Chloroform (1)
- Clinoptilolite (1)
- Constructed Wetlands (1)
- Constructed wetland (1)
- Contaminant (1)
- Desalination (1)
- Dichloromethane (1)
- Diffusion of innovation (1)
- Evapotranspiration (1)
- Faculty (1)
- Hanford Nuclear Reservation (1)
- Injection (1)
- Interview (1)
- Job (1)
- LID (1)
- Publication
- Publication Type
Articles 1 - 15 of 15
Full-Text Articles in Engineering
Dissolved Carbon Dioxide For Scale Removal In Reverse Osmosis, Erin Partlan
Dissolved Carbon Dioxide For Scale Removal In Reverse Osmosis, Erin Partlan
All Theses
Membrane fouling is a major operational issue in reverse osmosis (RO) desalination plants. In particular, plants treating brackish groundwater can encounter troublesome inorganic scales, including carbonates, sulfates, and silicates. A novel cleaning method is proposed to remove inorganic scales from fouled RO membranes usinag dissolved CO 2 . As CO2 molecules encounter membrane foulants, the surfaces serve as nucleation sites for small bubbles to form and shear off foulants. Dissolved CO2 solutions were prepared by bubbling CO2 gas into water held in a pressure vessel. Gas dissolution was confirmed by enhanced exit velocities for water containing CO …
Chemical, Physical, And Moisture Release Characteristics Of Compost Based Potting Media, Tianzhen Wang
Chemical, Physical, And Moisture Release Characteristics Of Compost Based Potting Media, Tianzhen Wang
All Theses
A commercially available composted cow manure was used as a potting media amendment. A common base mix for woody ornamentals of 8 parts pine bark and 1 part sand was compared with 3 other mixes that contained 20%, 30%, and 40% compost (v/v). The remaining fraction of these three mixes was the base mix (bark and sand). Samples of the pine bark and compost were analyzed to determine the following plant nutrients and mineral concentrations: nitrogen (organic and soluble), carbon, P2O5, K2O, Ca, S, Mg, Mn, Cu, Zn, Na, Fe, and Al.
Assessing Potential Environmental Impacts According To Probable Patterns Of Switchgrass Adoption In The Southeastern Us, Benjamin Sharp
Assessing Potential Environmental Impacts According To Probable Patterns Of Switchgrass Adoption In The Southeastern Us, Benjamin Sharp
All Dissertations
To assess the overall net impact of an emerging technology, life cycle assessment (LCA) must be accompanied by projections of adoption. Diffusion of innovation research provides tools that incorporate economic and social variables to explain and forecast integration of technologies. A switchgrass-to-ethanol case study for the southeastern U.S. is used to demonstrate methods for gauging aggregate environmental effects of an emerging energy technology. Before applying diffusion concepts, breakeven capacities are calculated for land in row crops, hay, pasture and marginal land. Breakeven curves are generated to provide upper bounds to switchgrass adoption over a range of farm-gate prices. The amount …
Renovation Of Ammonia Contaminated Produced Water Using Constructed Wetlands, Donald Beebe
Renovation Of Ammonia Contaminated Produced Water Using Constructed Wetlands, Donald Beebe
All Dissertations
Pilot-scale wetland treatment systems were designed and constructed to evaluate renovation of simulated oilfield produced water contaminated with ammonia (20 mg/L ammonia-N). A process-based pilot-scale constructed wetland was designed to meet specific biogeochemical conditions for conversion of ammonia to nitrogen gas through microbial nitrification and denitrification. The process-based constructed wetland treated the simulated produced water to meet stringent discharge requirements (less than 1.2 mg/L ammonia-N). Clinoptilolite, a zeolite mineral, was evaluated for use in constructed wetlands to increase ammonia sorption and nitrification activity. Clinoptilolite increased wetland ammonia sorption capacity and served as a microbial carrier for nitrifying bacteria when ranges …
Air Pressure Energy Storage For Reverse Osmosis: Bench-Scale Proof Of Concept, Ying Sun
Air Pressure Energy Storage For Reverse Osmosis: Bench-Scale Proof Of Concept, Ying Sun
All Theses
Society faces diminishing access to clean drinking water because of increasing global population and the development of modern industries. At the same time, climate change and other environmental problems caused by the increase in fossil fuel consumption the emphasis on reducing dependency on traditional energy resources in the process of potable water production. To address both problems, a small-scale wind powered reverse osmosis (RO) desalination system with a unique energy storage mechanism was envisioned to provide an energy buffer such that fluctuating and intermittent wind can be utilized. Energy is stored in the form of compressed air in a pressure …
Describing Plutonium Contamination Issues In Hanford Soils: Development Of A Thermodynamic Surface Complexation Model, Sarah Herr
All Theses
The development of remediation strategies for long-term site management requires knowledge of an actinide's geochemical behavior. Understanding this behavior can lead to the formation of a subsurface transport model. For example, plutonium mobility in the subsurface environment is significantly influenced by oxidation-reduction and complexation reactions. This work considered the surface-mediated reduction of plutonium, as well as the hydrolysis and carbonate complexation of the actinide.
Evaluating the significance of these reactions required several variable pH batch sorption studies. Experiments incorporated plutonium and neptunium sorption to sediments from the Hanford Nuclear Reservation in Washington State. Two different sediments were examined: coarse-grained and …
Removal Of N-Nitrosodimethylamine And Trihalomethane Precursors With Powdered Activated Carbon, Wilson Beita Sandi
Removal Of N-Nitrosodimethylamine And Trihalomethane Precursors With Powdered Activated Carbon, Wilson Beita Sandi
All Theses
N-nitrosodimethylamine (NDMA) has been used commercially in several applications, including the production of liquid rocket fuel, and a variety of foods, but gained more relevance when it was discovered as a drinking water disinfection by-product (DBP) in 1989. NDMA is a probable human carcinogen with 10-6 lifetime cancer risk associated with a drinking water concentration of 0.7 ng/L, and is listed as a priority pollutant in the Code of Federal Regulations; no federal maximum contaminant level has been established for drinking water yet. However, the United States Environmental Protection Agency is planning to make a preliminary regulatory determination in 2013 …
Removal Of Arsenic From Simulated Groundwater Using A Pilot-Scale Constructed Wetland Treatment System, Jeffrey Schwindaman
Removal Of Arsenic From Simulated Groundwater Using A Pilot-Scale Constructed Wetland Treatment System, Jeffrey Schwindaman
All Theses
A pilot-scale constructed wetland treatment system (CWTS) was designed and built to produce biogeochemical conditions that promoted targeted processes for removal of arsenic from simulated groundwater. Two series were designed to promote co-precipitation and sorption of arsenic with iron oxyhydroxides under oxidizing conditions, and two series were designed to promote precipitation of arsenic sulfide and co-precipitation of arsenic with iron sulfide under reducing conditions. The two major objectives were to (1) assess arsenic removal performance and (2) determine the fate and distribution of arsenic in each series. Results indicate that arsenic removal performance was greater in series designed to promote …
Evaluation Of Anaerobic Biodegradation Of High Concentrations Of Halogenated Methanes, Priya Rachel Jacob
Evaluation Of Anaerobic Biodegradation Of High Concentrations Of Halogenated Methanes, Priya Rachel Jacob
All Theses
Removal of the chlorinated methanes, carbon tetrachloride (CT), chloroform (CF) and dichloromethane (DCM), and the halogenated methane, trichlorofluoromethane (commonly known as CFC-11 or Freon-11) from contaminated soil and groundwater remains challenging. Releases to the environment resulted from historically poor disposal practices, as well as spills and leaks from underground storage tanks. Among these three compounds, CF is considered the benchmark for evaluating the feasibility of bioremediation, due to its typically high level of toxicity towards most anaerobic prokaryotes. However, inhibitory effects of low concentrations of CFC-11 on anaerobes have been reported as well. Bioremediation is an attractive option for clean-up, …
The Extraction Of Acetic Acid From Thermotoga Neapolitana Fermentation Spent Medium Using Fresh/Recovered Aliquat 336 And Produce Cma, Yifan Du
All Theses
To offer an alternative pathway to produce calcium magnesium acetate (CMA) as an environmental friendly deicer to relieve the pressure on fossil fuels demand, a liquid-liquid extraction process was studied. This process includes using Aliquat 336 (tri-n-octylmethylammonium chloride) diluted in kerosene as an organic extractant to extract acetic acid from Thermotoga neapolitana fermentation spent medium, which contained 34 g/L of acetic acid and 10 g/L of NaCl.
The extraction efficiency of Aliquat 336 was studied under several different extraction conditions. The initial pH of the spent medium was adjusted to a pH range of 2.25 to 5.75 with a 0.5 …
Improvement Of Onsite Wastewater Treatment By Use Of Electrically Conductive Carbon Cloth, Christopher Weber
Improvement Of Onsite Wastewater Treatment By Use Of Electrically Conductive Carbon Cloth, Christopher Weber
All Theses
The purpose of this research is primarily focused on carbon oxidation in domestic septic systems. Small-scale septic waste reactors utilizing electrically conductive carbon cloth were assessed for improving carbon oxidation and therefore the overall efficiency of on-site wastewater treatment systems.
A bioelectrochemical system was developed to enhance carbon oxidation in septic systems using electrically conductive carbon cloth as an anode/cathode bridge to transfer electrons from strictly anoxic septic wastewater to an oxic system outside of the septic reactor. This 'septic snorkel' (so named since the system 'breathes' via the carbon cloth extends into an aerobic zone) was designed to lower …
Modeling Benefits Of Implementing Low Impact Development Practices Within Forecasted Growth Scenarios Of The Reedy River Watershed, Stephen Taylor
Modeling Benefits Of Implementing Low Impact Development Practices Within Forecasted Growth Scenarios Of The Reedy River Watershed, Stephen Taylor
All Theses
For this research, a previously developed comprehensive watershed water quality model for the Reedy River as developed for South Carolina Department of Health and Environmental Control (SCDHEC) and the US Environmental Protection Agency (EPA) as a total maximum daily load (TMDL) assessment tool was used to assess the benefits of using low impact development (LID) designs in future growth of Greenville County, within the Reedy River watershed. The original intent of this model was to provide SCDHEC with a defensible model that could be used to prepare nutrient TMDLs for an area located at Boyd Millpond and the Reedy River …
Navigating The Academic Job Search For Environmental Engineers: Guidance For Job Seekers And Mentors, David A. Ladner, Stephanie C. Bolyard, Defne Apul, Andrew J. Whelton
Navigating The Academic Job Search For Environmental Engineers: Guidance For Job Seekers And Mentors, David A. Ladner, Stephanie C. Bolyard, Defne Apul, Andrew J. Whelton
Publications
Students and postdoctoral associates interested in tenure-track environmental engineering positions have limited resources to aid them. The Student Services Committee (SSC) of the Association of Environmental Engineering and Science Professors (AEESP) organized a workshop to fill some of the need. Newly hired faculty and experienced search committee and department chairs shared information on how to create competitive applications. Students and postdoctoral associates were also provided with individualized feedback on their faculty application packages. Survey data were collected for all participants, and these data are presented in this paper along with tips shared during the workshop and information collected from the …
Aerosol Delivery As A Method For Enhancing Remedial Application In Contaminated Vadose Zones, Richard Hall
Aerosol Delivery As A Method For Enhancing Remedial Application In Contaminated Vadose Zones, Richard Hall
All Dissertations
Remediation of contaminated vadose zones is often hindered by an inability to effectively distribute liquid- or solid-phase amendments. Many amendment-based approaches, such as bioremediation, chemical oxidation, and reactive barriers have been successful in saturated formations. However, these remedial approaches have seen limited application in unsaturated materials, largely because of difficulties delivering amendments.
Aerosol delivery is a promising approach for distributing amendments in contaminated vadose zones. The amendments are aerosolized, creating a cloud of micron to sub-micron-scale liquid droplets held suspended in a gas by Brownian motion. During injection into porous media, the aerosol particles are transported along with the gas …
Influence Of Pcb-Contaminated Water Bodies On The Pcb Content Of Riparian Vegetation Through Foliar Deposition, Timothy Matthew Sattler
Influence Of Pcb-Contaminated Water Bodies On The Pcb Content Of Riparian Vegetation Through Foliar Deposition, Timothy Matthew Sattler
All Theses
Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that are generally considered semi-volatile. Volatilization and transport of PCBs from contaminated water bodies can result in PCB accumulation on terrestrial plant surfaces, acting as an entry point for contaminants into terrestrial food webs. Evergreen plants can serve as biomonitors of this PCB accumulation, as they often retain foliage for several years, allowing for greater concentrations to accumulate and subsequently be measured. Rhododendron maximum plants often grow in the riparian zone adjacent to water bodies in the Appalachian region, such as near Town Creek, Pickens, South Carolina. This research aimed …