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Environmental Engineering

Clemson University

2011

Articles 1 - 10 of 10

Full-Text Articles in Engineering

Evaluation Of Bioaugmentation Strategies To Treat High Concentrations Of Chloroform And Carbon Tetrachloride, Han Wang Dec 2011

Evaluation Of Bioaugmentation Strategies To Treat High Concentrations Of Chloroform And Carbon Tetrachloride, Han Wang

All Theses

Halogenated methanes, including carbon tetrachloride (CT) and chloroform (CF), are significant groundwater contaminants. Options for bioremediation of high concentrations are limited. Previous studies have shown that an enrichment culture (designated DHM-1) that grows on corn syrup has the potential for use in bioaugmentation. DHM-1 cometabolically biotransforms high concentrations of CT and CF to nontoxic end products (mainly CO, CO2, and organic acids) in the presence of vitamin B12 (approximately 3% of chlorinated methanes on a molar basis). Sulfide is also required by this culture to function properly. However, insufficient data are available on its performance under field conditions. Also, it …

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Contaminant Mass Transfer During Boiling In Fractured Geologic Media, Fei Chen Aug 2011

Contaminant Mass Transfer During Boiling In Fractured Geologic Media, Fei Chen

All Dissertations

Remediation of fractured geologic media contaminated with chlorinated volatile organic compounds that diffuse into the matrix is challenging using isothermal methods. Due to the low permeability of the matrix material and uncertainty of fracture networks, it is difficult to flush the system with any type of fluid or deliver remediation agents into the matrix. However, thermal methods have some promises. When the matrix is heated above water boiling temperature, depressurization in the fractures may trigger water boiling in the matrix, which, as a result, generates a large volumetric steam flow toward adjacent fractures, stripping the adsorbed or dissolved volatile contaminants …

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Determination Of Freshwater Algal Biomass And Sulfolipid Content As Functions Of Inorganic Carbon Treatment, Melissa Morella Aug 2011

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

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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 …

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A History-Dependent Nonwetting Phase Trapping Model For Multiphase Flow Characteristic Curves, Christopher Patterson Aug 2011

A History-Dependent Nonwetting Phase Trapping Model For Multiphase Flow Characteristic Curves, Christopher Patterson

All Theses

Characteristic curves used in numerical multiphase flow simulators describe relative permeability-saturation and capillary pressure-saturation relationships for flow simulations. Characteristic curves are typically non-hysteretic; meaning they are monotonic functions of saturation and are limited to a single value for residual saturation. Implications of residual saturation are important for environmental, petroleum, and geologic carbon sequestration modeling. However, hysteretic characteristic curves predict that trapped residual saturation depends on the local saturation history. The use of hysteretic characteristic curves is critical to predicting the residual saturation and ultimately the mobility of a nonwetting phase such as supercritical CO2 or a nonaqueous phase liquid (NAPL). …

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Influence Of Natural Organic Matter On Plutonium Sorption To Gibbsite, Laura Simpkins Aug 2011

Influence Of Natural Organic Matter On Plutonium Sorption To Gibbsite, Laura Simpkins

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Understanding plutonium geochemical behavior is imperative to the development of schemes for remediation of plutonium environmental contamination and accurate assessment of risks posed by the disposal of plutonium bearing wastes. The primary mechanism of plutonium mobility in the environment is subsurface transport. The mobility of plutonium is significantly influenced by redox and complexation reactions. Although the effects of surface mediated redox reactions on plutonium's subsurface mobility have been previously documented, little has been done to determine the impact of organic materials on sorption behavior and oxidation states. To adequately predict the behavior of plutonium in the environment, the influence of …

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Applications Of Moderate-Resolution Remote Sensing Technologies For Surface Air Pollution Monitoring In Southeast Asia, Arika Bridhikitti May 2011

Applications Of Moderate-Resolution Remote Sensing Technologies For Surface Air Pollution Monitoring In Southeast Asia, Arika Bridhikitti

All Dissertations

Retrievals from Earth observation satellites are widely used for many applications, including analyzing dynamic lands and measuring atmospheric components. This research aims to evaluate appropriateness of using satellite retrievals to facilitate understanding characteristics of Southeast Asian (SEA) surface air pollution, attributed to regional biomass burnings and urban activities. The studies in this dissertation focused on using satellite retrievals for 1) mapping potential SEA air pollution sources; which are forests, rice paddies, and urban areas, 2) understanding dynamic optical characteristics of SEA biomass-burning aerosols, and 3) inferring surface ozone level. Data used in this study were from three NASA's Earth Observing …

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Identification And Characterization Of Polychlorinated Biphenyl Dechlorinating Microorganisms From Lake Hartwell, Sc, Tess Brothersen May 2011

Identification And Characterization Of Polychlorinated Biphenyl Dechlorinating Microorganisms From Lake Hartwell, Sc, Tess Brothersen

All Dissertations

To date, all attempts to isolate PCB dechlorinators using traditional isolation techniques have failed. In addition, the study of PCB dechlorinating organisms has been hampered because researchers were unable to grow the organisms in sediment-free, defined media. Three microbial species capable of reductive dechlorination of polychlorinated biphenyls have been identified. These three species are from two phylogenetically distinct branches, Dehalococcoides (Bedard et al., 2007) and the DF-1/o-17 group (Wu et al., 2002a; Cutter et al., 2001). The three cultures from which polychlorinated biphenyl dechlorinators have been identified used similar strategies to 'wean' the microbes from the sediments. In this research, …

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Evaluation Of Manganese Control In The Source Water And Microfiltration Plant Of A South Carolina Water Utility, Daniel Lewis May 2011

Evaluation Of Manganese Control In The Source Water And Microfiltration Plant Of A South Carolina Water Utility, Daniel Lewis

All Theses

Although present in most water supplies, manganese is a difficult-to-treat nuisance contaminant in drinking water. The US Environmental Protection Agency (EPA) has set a Secondary Maximum Contaminant Level (SMCL) of 0.05 mg/L but experts have recommended a goal of 0.02 mg/L or less to avoid chronic issues with the metal. This work is a report on manganese control for the Startex-Jackson-Wellford-Duncan (SJWD) Water District, a water utility in northwestern SC. Fourteen locations were sampled from June 2010 through October 2011. Manganese, iron, dissolved organic carbon, dissolved oxygen, and other relevant parameters were measured.
The lake-fed Middle Tyger River is the …

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Fate And Transport Of Escherichia Coli Within Sediment Basins On Active Construction Sites, Elizabeth Tempel May 2011

Fate And Transport Of Escherichia Coli Within Sediment Basins On Active Construction Sites, Elizabeth Tempel

All Theses

The conventional method of controlling sediment-laden runoff on construction sites is the use of sediment basins. These basins slow the velocity of runoff and allow the particles to settle from the water column before discharge to surface waters offsite. This best management practice, however, may create a reservoir for pathogenic bacteria. Sediment is known to provide protection for bacteria; therefore, while these basins decrease sediment loadings to water bodies downstream, they may introduce harmful levels of pathogenic bacteria into these surface waters. In addition to causing human health risks, these high bacteria levels alter natural biological makeup of downstream ecosystems. …

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Biodegradation Kinetics For 1,2-Dichloroethane And Ethylene Dibromide In Anaerobic Enrichment Cultures Grown On Each Compound, Rong Yu Jan 2011

Biodegradation Kinetics For 1,2-Dichloroethane And Ethylene Dibromide In Anaerobic Enrichment Cultures Grown On Each Compound, Rong Yu

All Theses

1,2-Dichloroethane (DCA) and ethylene dibromide (EDB) are among the top 15 chlorinated aliphatic compounds on the Agency for Toxic Substances and Disease Registry's Priority List of Hazardous Substances. Co-contamination of groundwater with EDB and 1,2-DCA resulted mainly from environmental releases of leaded gasoline; these compounds were added as lead scavengers. A microcosm study by Henderson et al. with soil and groundwater from a site contaminated with leaded gasoline demonstrated anaerobic biodegradation of EDB at a higher rate, and to a greater extent, than 1,2-DCA. Both compounds were transformed mainly by dihaloelimination to ethene. The objectives of this study were to …

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