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Articles 91 - 114 of 114
Full-Text Articles in Environmental Engineering
Biological Treatment To Remove Color And Toxicity Of Effluent From The Manufacturing Of Navipol Yellow Gr, Larry French
Biological Treatment To Remove Color And Toxicity Of Effluent From The Manufacturing Of Navipol Yellow Gr, Larry French
All Theses
Navipol Yellow GR is an organic solvent azo dye manufactured by Sunbelt Corp. in Rock Hill, SC. The effluent generated from the manufacturing of this dye is highly colored, toxic, and contains trace solvents consisting of mixed xylene isomers and ethyl benzene. Traditional wastewater treatment systems are unable to remove the color and toxicity from the effluent. This study investigated using a sequential anaerobic / aerobic treatment system to decrease color and toxicity of the dye effluent. The anaerobic phase used bacteria cultures of Pseudomonas aeruginosa, Bacillus subtilis, Enterococcus faecalis, or Enterobacter aerogenes to decrease the color of the dye. …
The Characterization, Isolation, And Fractionation Of Natural Organic Matter From Three Surface Waters, Olivia Orr
The Characterization, Isolation, And Fractionation Of Natural Organic Matter From Three Surface Waters, Olivia Orr
All Theses
The main objective of this study was to gain insight to the principles of isolation of natural organic matter (NOM) using reverse osmosis (RO) and subsequent fractionation using resin adsorption chromatography (RAC). Specifically, this study evaluated the RO and RAC methods for NOM characterization from three surface waters with varying physiochemical characteristics. Efficiency of RO was assessed by closing mass balances for dissolve organic carbon (DOC). Mass balances were also closed for dissolved nitrogen (DN), bromide (Br-), nitrate (NO3-), total calcium (Ca), total potassium (K), total manganese (Mn), total iron (Fe), total magnesium (Mg), total aluminum (Al), total copper (Cu), …
Leaching Of Dissolved Organic Carbon And Selected Inorganic Constituents From Scrap Tires, Meric Selbes
Leaching Of Dissolved Organic Carbon And Selected Inorganic Constituents From Scrap Tires, Meric Selbes
All Theses
An environmentally friendly method for the disposal of scrap tires is currently unavailable; as a result, ultimate disposal of used vehicle tires continues to be a major challenge around the world. In the United States (US), during the past two decades, scrap tires have been generated at the rate of approximately one tire per person per year (i.e., approximately 290 million new scrap tires every year). It is estimated that there are currently 2 billion tires stockpiled in the US. Due to various problems involved in the disposal of scrap tires, different alternatives for recycle and reuse have been examined; …
Modeling Nitrogen Loss From Regional Switchgrass Agriculture, Saumya Sarkar
Modeling Nitrogen Loss From Regional Switchgrass Agriculture, Saumya Sarkar
All Theses
A water quality modeling study was conducted to determine and compare nitrogen loss from agricultural systems growing switchgrass and cotton in the southeastern USA. The water quality impacts were modeled at the plot scale and at the watershed scale. The Soil and Water Assessment Tool (SWAT) was used to replicate field conditions observed at switchgrass research plots at Pee Dee Research and Educational Center at Florence, South Carolina. The plot scale modeling suggested that in the early years of growth there is significant nitrogen loss from switchgrass to streamflow and groundwater but they are significantly less as the switchgrass matures. …
Effect Of Nitrification On Lead Corrosion In Chloraminated Distribution Systems, Michael Shade
Effect Of Nitrification On Lead Corrosion In Chloraminated Distribution Systems, Michael Shade
All Theses
Water treatment facilities have been shifting from using chlorination to chloramination as a primary disinfectant since 2004, when the EPA enacted the Disinfectants/Disinfection By-Products (D/DBP) Rule mandating the decrease of DBPs. After the switch to chloramination, an unexpected lead concentration increase was detected in the Washington, D. C., and Greenville, NC water systems. These increases may be associated with the switch from chlorination to chloramination. Decomposition of chloramines results in higher ammonia loading to drinking water distribution systems, which may increase nitrification. Nitrifying bacteria may facilitate lead corrosion via two mechanisms: use of nitrite or nitrate as an alternative electron …
Spatial Variability Of Radionuclide Distribution Coefficients At The Savannah River Site And The Sub-Surface Transport Implications, Kelly Grogan
All Theses
Distribution coefficients, Kd, were measured for a suite of gamma-emitting radionuclides in uncontaminated soils from the E-Area burial grounds at the Savannah River Site. The objectives of the study were to (1) characterize the spatial variability of Kd, (2) evaluate the effect of spatial variability on vadose zone transport, and (3) develop statistical models for predicting Kd from physical or chemical characteristics.
Equilibrium batch sorption tests were performed on 27 soil samples collected from depths ranging from 11 ft to 100 ft from the BGO-3A core with 241Am, 109Cd, 139Ce, 137Cs, 57Co, 60Co, 203Hg, 85Sr, and 88Y. Distribution coefficients were …
Laboratory Evaluation Of Polycyclic Aromatic Hydrocarbon Biodegradation At A Former Tar Plant Site, Mihika Baruah
Laboratory Evaluation Of Polycyclic Aromatic Hydrocarbon Biodegradation At A Former Tar Plant Site, Mihika Baruah
All Theses
A former tar plant site in the southeastern
U.S. is one of hundreds across the country that is contaminated with polycyclic
aromatic hydrocarbons (PAHs). The 2007
CERCLA Priority List of Hazardous Substances ranks PAHs as the eighth most
prominent hazardous substance at National Priority List sites. However, benzo(a)pyrene
is the only PAH that is regulated under the Safe Drinking Water Act, with a maximum
contaminant level of 0.2 µg/l. As with most sites, monitored natural
attenuation was the preferred bioremediation approach for this site, assuming
it could be shown that the PAHs were undergoing biodegradation. Field data from the site …
Exploration Of A Carbon Nanotube Anode Gas-Filled Radiation Detector, Landon Pruitt
Exploration Of A Carbon Nanotube Anode Gas-Filled Radiation Detector, Landon Pruitt
All Theses
The primary objective of this study was to design, test, and model the electrostatic field in a gas-filled radiation detector constructed with either a carbon nanotube (CNT) or a CNT array as the anode. Tungsten anodes of 500 to 4μm diameters were used to observe the gradual decrease in operating voltage with a decreasing anode diameter and estimate efficiencies of CNT anodes in a coaxial design. An electrostatic model (Maxwell 3D/2D) was used to model the resulting electric field associated with a single CNT in the coaxial configuration as well as to optimize the pitch (distance between individual CNTs in …
Scale-Up And Characterization Of An Enrichment Culture For Bioaugmentation Of The P-Area Chlorinated Ethene Plume At The Savannah River Site, Ashley Eaddy
All Theses
Bioaugmentation has become an increasingly popular remediation strategy for groundwater sites contaminated with chlorinated solvents. When biostimulation is not an option due to the lack of necessary microorganisms required for dechlorination of the contaminants, bioaugmentation is an attractive option for remediation. The P-Area groundwater plumes at the Savannah River Site (SRS) are just such a case. The P-Area site is contaminated with tetrachloroethene (PCE), trichloroethene (TCE), and cis-dichloroethene (cDCE), and no dechlorination past cDCE is occurring. A similar site, the C-Area site, is near one of the P-Area site's source zones but displays complete reduction of TCE to ethene. …
Microcosm Evaluation Of Vinyl Chloride Bio-Oxidation Under Anaerobic Conditions, Jessica High
Microcosm Evaluation Of Vinyl Chloride Bio-Oxidation Under Anaerobic Conditions, Jessica High
All Theses
The vast majority of hazardous waste sites in the US have groundwater contaminated with halogenated organic solvents, primarily tetrachloroethene (PCE) and trichloroethene (TCE). Because the cost to remediate these sites is projected to exceed hundreds of billions of dollars, there is considerable interest in utilizing bioremediation as a low-cost remedy. Under anaerobic conditions, the best characterized biodegradation pathway for chlorinated ethenes is reductive dechlorination, whereby an electron donor such as hydrogen provides the reducing equivalents needed to replace chlorine atoms with hydrogen atoms. The ultimate daughter products from chlorinated ethenes are non-hazardous ethene and ethane, a process easily documented with …
Fecal Coliform Source Identification Using Chemical Tracers, Nicole Fahrenfeld
Fecal Coliform Source Identification Using Chemical Tracers, Nicole Fahrenfeld
All Theses
Fecal sterols and fluorinated whitening agents (FWA) were used as chemical tracers for fecal coliform source tracking in Cane and Little Cane creeks in Walhalla, SC. Fecal sterols were quantifiable in both stream sediments and suspended particulates using an extraction, clean-up, and analytical method modified from Isobe et al. (2002) with a N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA) derivatization scheme. Only human sterol source identification ratios were able to be calculated using the chosen sterol suite. Human fecal signatures were seen in both the sediment and the water column at various points along both creeks, indicating human fecal pollution is contributing to the fecal …
Development Of A Colorimetric Test For Quantification Of Uranium In Drinking Water, Amy Ratliff
Development Of A Colorimetric Test For Quantification Of Uranium In Drinking Water, Amy Ratliff
All Theses
A new method was developed for the determination of uranium in groundwater above 30µg/L (30ppb). This concentration is the maximum contaminant level (MCL) for uranium in drinking water, which was set in December 2003 by the US EPA under the provisions of the Safe Drinking Water Act. The method is rapid and requires little technical training to conduct, allowing it to be used by consumers, in the laboratory, or in the field. The two-step technique involves preconcentrating uranium using a U/TEVA-2 extraction chromatographic resin followed by complexation with a pyridylazo indicator dye, Br-PADAP. At neutral pH, a counter ion is …
Storm Water Export Of Nitrogen, Phosphorous, And Carbon From Developing Catchments In The Upper Piedmont Physiographic Province, Laura Reid
All Theses
Impacts on water quality caused by land use change from forests and pastures to housing subdivisions were evaluated in catchments undergoing active development in the upper Piedmont physiographic province of South Carolina. Specific attention was focused on the export of nitrogen, phosphorus and carbon from these catchments during storm events. Three catchments with varying stages of development were compared to categorize the effects of land disturbance. Storm events occurring within a four year period of 2004 through 2007 were studied for changes in water quality within catchment streams. Due to the potential large input of surface runoff to streams following …
The Formation Of Halonitromethanes In Wastewater Treatment Plant Effluents, Jesse Addison
The Formation Of Halonitromethanes In Wastewater Treatment Plant Effluents, Jesse Addison
All Theses
Disinfection by-products (DBPs) have been a water treatment concern since their discovery in the 1970's. Today, only eleven drinking water DBPs are regulated by the Environmental Protection Agency (EPA). However, over 500 DBPs have been identified in drinking waters with advances in analytical methods within the last two decades. Halonitromethanes (HNMs) were among the fifty-plus unregulated high-priority DBPs that were monitored for and detected in drinking waters in a recent nationwide occurrence study funded by EPA. The toxicology studies conducted in recent years showed that HNMs are one of the most cytotoxic and genotoxic classes among the emerging DBPs, and …
Bacterial Auto-Aggregation And Co-Aggregation In Activated Sludge, Fei Chen
Bacterial Auto-Aggregation And Co-Aggregation In Activated Sludge, Fei Chen
All Theses
Microbial auto-aggregation and co-aggregation, leading to biofilm or floc formation, widely occur in natural systems. This study was conducted to investigate the extent of bacterial auto-aggregation and co-aggregation in activated sludge and their contributions in activated sludge floc formation. In this study, an activated sludge sample was separated into a supernatant part (planktonic community) and a sediment part (floc community) by centrifugation at 650_g for 2 minutes. 197 strains were isolated from both communities. These isolates belong to 18 phylotypes based on molecular identifications. Similar phylogenetic distributions of these isolates were observed in planktonic and floc communities, suggesting a similar …
Metalloporphyrin Catalyzed Degradation Of Pce: Effects Of Reductants, Buffers And Cosolvent Concentration, Sowmya Suryanarayanan
Metalloporphyrin Catalyzed Degradation Of Pce: Effects Of Reductants, Buffers And Cosolvent Concentration, Sowmya Suryanarayanan
All Theses
Reductive dechlorination of chlorinated organic contaminants using metalloporphyrins as catalysts may be an effective approach to treat widespread contamination. However, most previous studies have examined water-soluble rather than insoluble metalloporphyrins despite the fact that the latter category makes up the largest fraction found in nature. Recent studies have shown that addition of different cosolvents to water can activate otherwise non-reactive metalloporphyrin catalysts and facilitate the reduction of tetrachloroethylene (PCE), presumably by the mere process of making the otherwise insoluble metalloporphyrins dissolve in solution. Therefore, solubility has been advanced as a key factor in the ability of metalloporphyrins to catalyze organic …
Laboratory Evaluation Of Microbial Aggregation In Activated Sludge, Xiaoling Liu
Laboratory Evaluation Of Microbial Aggregation In Activated Sludge, Xiaoling Liu
All Theses
Microbial aggregation was investigated in this study using the activated sludge process as a model system, the performance of which is highly dependent on effective bioaggregation. This research includes two experiments. First, four laboratory-scale activated sludge sequencing batch reactors (SBRs) were constructed in order to evaluate the effect of solids retention time (SRT) on microbial aggregation. These SBRs were operated at SRT of 4, 8, 16, and 32 days, respectively, fed with a protein-based synthetic wastewater, and monitored over a period of 268 days for performance and sludge settling characteristics including soluble COD in the effluent (sCOD), sludge volume index …
Cosolvent Effects On The Reductive Dechlorination Of Tetrachloroethylene Catalyzed By Iron Tetraphenyl Porphyrin Chloride, Lavanya Ramasubramanian
Cosolvent Effects On The Reductive Dechlorination Of Tetrachloroethylene Catalyzed By Iron Tetraphenyl Porphyrin Chloride, Lavanya Ramasubramanian
All Theses
Abiotic electron transfer mediated reductive dechlorination reactions have been studied extensively in the past decade. Porphyrins and metalloporphyrins are common electron transfer mediators used. Past studies have shown that some metalloporphyrins play a key role in increasing the rate of reaction in the presence of cosolvents. There have also been suggestions that organic cosolvents enhance the rate of reduction by increasing the solubility of metalloporphyrins.
The primary objective of this project was to examine the effect of cosolvents on the metalloporphyrin-catalyzed reductive dechlorination of tetrachloroethylene (PCE). Subsequently, experiments were also conducted to test the hypothesis that metalloporphyrin solubility is linked …
Achiral And Chiral Analysis Of Polychlorinated Biphenyls (Pcbs) In The Aquatic And Riparian Food Webs In Twelve Mile Creek, South Carolina., Viet Dang
All Theses
Polychlorinated biphenyls (PCBs) contamination in the Twelve Mile Creek arm of Lake Hartwell, South Carolina, has been an issue for decades. Lake Hartwell, which is a reservoir located on the border between the states of South Carolina and Georgia, was contaminated with an estimated 440,000 pounds of PCBs. PCBs were released from the Sangamo-Weston capacitor plant located on Town Creek, which feeds into Twelve Mile Creek and ultimately Lake Hartwell. The Twelve Mile Creek tributary connecting the Sangamo-Weston plant to Lake Hartwell has had little attention. Understanding PCBs contamination in the aquatic and riparian food webs of Twelve Mile Creek …
Development And Evaluation Of An Enrichment Culture For Bioaugmentation Of The P-Area Chlorinated Ethene Plume At The Savannah River Site, Elizabeth Wood
Development And Evaluation Of An Enrichment Culture For Bioaugmentation Of The P-Area Chlorinated Ethene Plume At The Savannah River Site, Elizabeth Wood
All Theses
The Twin Lakes chlorinated ethene plume at the Department of Energy's
Savannah River Site (SRS) emerges in a wetland in which trichloroethene (TCE) is
completely reduced to ethene and ethane. Novel strains of Dehalococcoides have been
detected from the wetland area. The objectives of this study were 1) to develop an
enrichment culture capable of completely dechlorinating TCE and tetrachloroethene
(PCE) to ethene using samples from the wetland; 2) to evaluate the use of lactate,
emulsified vegetable oil and corn syrup as possible electron donors for biostimulation of
the P-area chlorinated ethene plume at SRS that is not undergoing natural …
Approaches To Mitigate The Impact Of Dissolved Organic Matter On The Adsorption Of Synthetic Organic Contaminants By Activated Carbon, Abhishek Yadav
Approaches To Mitigate The Impact Of Dissolved Organic Matter On The Adsorption Of Synthetic Organic Contaminants By Activated Carbon, Abhishek Yadav
All Theses
The main objective of this study was to conduct a systematic investigation of various approaches to mitigate the competition of dissolved organic matter (DOM) on the adsorption of synthetic organic contaminants (SOCs) by activated carbons. TCE and atrazine were selected as the target SOCs because they are known to adsorb in different pore size regions. TCE adsorbs in the primary micropore region (i.e., <10 ) which is inaccessible to the majority of the DOM components, while atrazine adsorbs in the secondary micropore region (i.e., 10-20 ) which is partially accessible to some DOM components. The adsorbents used in this study consisted of four activated carbons (OLC, CRC, F400He, and HD4000ST) and one activated carbon fiber (ACF: ACF10). All sorbents were basic and hydrophobic in nature and represented a set of activated carbons with gradually widening pore size distribution, from the extremely microporous carbons (ACF10 and OLC) to carbons with some amount of mesopores (CRC and F400He) and finally a predominantly mesoporous (HD4000ST) carbon.
Isotherms were performed as single solute and after preloading with a dissolved organic matter (5 mg DOC/L and 20 mg DOC/L) for both TCE and atrazine and using the five activated carbons. Single solute isotherm results showed …
Characterization Of The Ibc Technologies Superlig¨ 620 Solid Phase Extraction Resin With Applications For Automated Process Monitoring, John Clements
Characterization Of The Ibc Technologies Superlig¨ 620 Solid Phase Extraction Resin With Applications For Automated Process Monitoring, John Clements
All Theses
Characterization of the IBC Advanced Technologies SuperLig¨ 620 solid phase extraction resin was performed in order to develop an automated strontium-90 process monitor. The main focus was on strontium separation from barium, with the goal of developing an automated separation process for strontium-90 in Hanford high-level tank wastes. High-level waste tanks contain significant cesium-137 activities, of which barium daughters are of great concern as interferences to strontium quantification. A number of complexants were studied in a series of batch distribution coefficient experiments, as SuperLig¨ 620 was not previously known to elute strontium in typical mineral acids. The optimal separation was …
Application Of Classical Versus Bayesian Statistical Methods To On-Line Radiological Monitoring, Amy Attardo
Application Of Classical Versus Bayesian Statistical Methods To On-Line Radiological Monitoring, Amy Attardo
All Theses
The on-line monitoring for illicit radioactive material with a minimum number of false detections is a critical need for homeland security. The primary objectives of this work were to apply both Bayesian and classical statistical process control chart techniques to the on-line monitoring of radiological data and to then compare the Type I and Type II error incidence rates. Two versions of the cumulative sum (CUSUM) and Shiryayev-Roberts (S-R) procedures known as total reset and alarm reset methods were developed. The best method in terms of Type I errors was the S-R total reset method. In terms of Type II …
A Comparison Of The Zns(Ag) Scintillation Detector To The Silicon Semiconductor Detector For Quantification Of Alpha Radioactivity In Aqueous Solutions, Jennifer Foster
A Comparison Of The Zns(Ag) Scintillation Detector To The Silicon Semiconductor Detector For Quantification Of Alpha Radioactivity In Aqueous Solutions, Jennifer Foster
All Theses
A ZnS(Ag) detector was successfully used in the direct detection of alpha particles from aqueous solutions and the results were compared to the passivated ion implanted planar silicon (PIPS) continuous air monitor (CAM) detector. The ZnS(Ag) detector is recommended for on-line detection of gross alpha radioactivity from high-level liquid waste process streams; however, the detector suffers from limitations due to variations in detection efficiency with alpha energies. The beta and gamma interference did not significantly spillover into the alpha region of interest of the ZnS(Ag) detector which provided absolute detection efficiencies of 7.19 ± 0.13%, 5.37 ± 0.02%, and 4.21 …