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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Effects of Total Dissolved Solids on Locomotory Behavior and Body Weight of Streamside Salamanders, and a Baseline Survey of Salamander Diversity and Abundance

Pascuzzi, Meghan 16 April 2012 (has links)
Increased levels of total dissolved solids (TDS) in stream habitats are of concern due to salinity as well as the presence of potentially toxic ions. Natural gas drilling in the Marcellus shale could increase TDS in nearby streams. This thesis investigated the effects of water with elevated TDS on the locomotory activity and body weight of the streamside salamander Desmognathus ochrophaeus. Salamanders were exposed to water collected from streams in southwest Pennsylvania with elevated TDS as well as synthetic ion solutions that mimicked the ionic composition found in streams. Chronic, but not acute exposure to solutions of 1000 ppm TDS caused significant differences in weight loss and locomotory activity, although the effect depended on the exact ion composition of the dissolved solids. Finally, field surveys of salamander abundance were completed on two streams to provide baseline data with which to track population changes should the TDS in the streams increase. / Bayer School of Natural and Environmental Sciences / Biological Sciences / MS / Thesis
2

Field Indicators for the Prediction of Appalachian Soil and Bedrock Geochemistry

Johnson, Daniel K. 03 August 2016 (has links)
Surface mining for coal in the Central Appalachians contributes total dissolved solids (TDS) to headwater streams, especially below larger mines and associated valley fills. My objective was to characterize the geochemical properties of a range of surface soils and associated geologic strata from the Central Appalachian coalfields and to relate those properties to simple field indicators, such as color or rock type. I hypothesized that these indicators can accurately predict certain geochemical properties. Thirty-three vertical weathering sequences were sampled from eight surface mines throughout the Central Appalachian coalfields, for a total of 204 individual samples. No differences were found among sites in overall saturated paste specific conductance (SC; used as a proxy for TDS) levels, but significant geochemical differences existed among samples. Sulfate release dominated SC levels, followed closely by Ca and Mg. Surficial soils and sandstones were yellowish-brown in color, high in citrate dithionite (CD) - extractable Al, Fe, and Mn, and low in SC, compared to underlying sandstones, shales, and mudstones, which were grayish to black, low in CD-extractable Al, Fe, and Mn, and significantly higher in SC. Saturated paste As and P were higher in A horizons, whereas Se was significantly higher in unweathered bedrock than in soil or weathered bedrock. Samples generating exothermic reactions with 30% H2O2 produced higher SC levels, sulfate, Mg, and Se. In conclusion, the mine spoils studied varied widely in geochemical properties. The simple field indicators presented here, such as color, weathering status, rock type, and H2O2 reaction can provide valuable guidance for identifying TDS risk which would greatly improve operator's ability to actively minimize TDS release. I recommend using soil and weathered, yellowish-brown sandstone layers as a source of low TDS spoil material whenever possible. The H2O2 field test is useful for identification of TDS and Se risk. Underlying unweathered bedrock layers should be treated as "potentially high TDS spoils". Particularly high risk spoils include gray to black mudstones and shales, coals, and coal associated shales, mudstones, and clays directly associated with coal seams. I recommend hydrologically isolating these spoils using techniques similar to those used historically for acid-forming materials. / Ph. D.
3

Effect of Various Saturation Levels, Leaching Solution pH, and Leaching Cycle on Electrical Conductivity from Coal Mine Spoil Leachate

Parker, John Martin 04 September 2013 (has links)
Historically, environmental research associated with Appalachian coal surface mines focused on acid mine drainage and reclamation. Recent studies suggest that electrical conductivity (EC) levels above 500 ?S cm-1 can impair Appalachian streams, shifting the focus towards limiting release of total dissolved solids (TDS) and associated elements of concern. Previous column studies utilized an unsaturated bi-weekly leaching design to evaluate the behavior of overburden with respect to TDS, pH, and trace metals. The objective of this study was to determine the effects of column saturation, leaching solution chemistry, and leaching cycle on the release of TDS and associated elements from an unweathered sandstone. Treatments evaluating potential saturation, leaching solution pH, and leaching cycle included saturated, standard method, vacuum, and standpipe fitted columns; simulated acid rain, de-ionized water, and CaCO3 leaching solutions; and 2x week-1, 1x week-1, 2x month-1, and 1x day-1 leaching cycles. Saturation level in the column significantly impacted leachate pH, EC level, and the release of sulfate, bicarbonate, and associated cations by potentially affecting trace sulfide oxidation and carbonate dissolution reactions. Little evidence of saturation was noted with the standard method. Leaching solution bulk chemistry did not alter leachate chemistry. Longer times between dosing cycles corresponded to higher EC, bicarbonate, and associated cation levels, especially over time. Sulfate, Ca, and Se exhibited the greatest percent release based on total mass losses during peak elution. For managing TDS, time between precipitation events and saturation level can strongly affect short and long-term EC level, its major contributors, and elements of concern. / Master of Science
4

Water Quality, Modeling, And Land Use Investigations In The Upper Pearl River Basin Of East-Central Mississippi

Tagert, Mary Love Mortimer 13 May 2006 (has links)
Little historical water quality data is available for the Upper Pearl River Basin (UPRB), yet there are UPRB waters listed as impaired. Objectives of this research were to measure pesticide and sediment concentrations in UPRB surface waters and validate the Annualized Agricultural Nonpoint-Source (AnnAGNPS) runoff model with the measured data for a portion of the UPRB. An additional objective was to quantify effects of land use changes on UPRB surface waters from 1987 to 2002 using AnnAGNPS. Of the fifteen compounds analyzed, hexazinone was most frequently detected, in 94% of samples, followed by metolachlor, tebuthiuron, and atrazine. Metribuzin was detected in only 6% of samples. Total dissolved solids (TDS) concentrations were highest at Carthage, which drains the largest area of three sites sampled for TDS. Most samples measured below Environmental Protection Agency (EPA) standards for pesticides and TDS in drinking water and also below levels toxic to aquatic organisms. For eight of twelve months analyzed between October 2001 and January 2003, average monthly sediment loadings for measured and AnnAGNPS-simulated data differed no more than 109%, resulting in an R&178; value of 0.328. A comparison of measured and simulated atrazine and metolachlor loadings by event resulted in R&178; values of 0.095 and 0.062, respectively. Most daily atrazine and metolachlor loadings for measured and predicted data were very low. On May 18, 2003, AnnAGNPS predicted a metolachlor loading of 80 mg, while measured data showed a loading of 5.6 mg. Measured data showed an earlier spike on January 20, 2003 that was not mirrored by the model. Atrazine comparisons followed the same trend, except measured loadings did not spike until February 22, 2003. The 2002 AnnAGNPS simulation resulted in 15% more average annual runoff than the 1987 simulation, although both simulations had the same precipitation. The 2002 simulation also had higher values for sediment and organic carbon loading. Nitrogen loading was the only runoff or pollutant loading category that was less for 2002 than for 1987. Urban land cover contributed more runoff and pollutant loadings from 1987 to 2002, while traditional row crop agriculture had less of an impact on pollutant loadings.
5

Effect of Leaching Scale on Prediction of Total Dissolved Solids Release from Coal Mine Spoils and Refuse

Ross, Lucas Clay 24 August 2015 (has links)
Coal surface mining in the Appalachian USA coalfields can lead to significant environmental impacts including elevated total dissolved solids (TDS) levels in receiving streams. Column leaching procedures are recommended by many studies for TDS prediction, but many question their applicability to field conditions. The objective of this study was to assess results from a simple column leaching method relative to larger scale leaching vessels (scales) using one coal mine spoil and two coarse coal refuse materials. A non-acidic mine spoil sample from SW Virginia (crushed to ≤ 1.25 cm) was placed into PVC columns (~10 cm x 40 cm) in the laboratory and leached unsaturated with simulated acidic rainfall. The same spoil was also placed into larger 'mesocosms' (~1.5 m³) with run-of-mine material and into barrels (~0.1 m³; screened to ≤ 15 cm) under natural field environmental and leaching conditions. Similarly, two coarse coal refuse samples were placed into lab columns and field barrels. Comparative results suggest the column method was a reasonable predictor of TDS release from the coal mine spoil relative to the two larger scales studied. However, there were significant differences at times during the study, including during initial peak TDS elution (1,750 µS cm⁻¹ in columns vs. 2,250 µS cm⁻¹ in mesocosms). Field leaching also produced a distinct seasonal time-lagged EC pattern that was not observed in the columns. On the other hand, significantly different and dissimilar leaching results were noted for the refuse column vs. barrel leachates, calling into question their prediction ability for refuse. / Master of Science
6

An Ecotoxicological Assessment of a Treated Coal-mining Effluent in the Leading Creek Watershed, Meigs County, Ohio

Kennedy, Alan James 06 January 2003 (has links)
The majority of research studying the ecological impacts of the coal mining industry on freshwater systems has focused on abandoned-mined land, and the associated acid drainage and metals toxicity. Treated discharges from active mining and preparation facilities, however, can also impair lotic ecosystems through total dissolved solids (TDS) toxicity, caused primarily by the reagents used for pH modifications and the oxidation of reduced sulfur. Such impairment was best detected through application of (1) benthic macroinvertebrate surveys using metrics of biotic impairment such as relative Ephemeroptera abundance and Ephemeroptera-Plecoptera-Trichoptera (EPT) minus the tolerant caddisfly family Hydropsychidae (2) in situ growth of Corbicula fluminea during 96-d exposure and (3) laboratory testing using Ceriodaphnia dubia. Traditional metrics such as total taxa richness, EPT, diversity and biotic indices were not sensitive to elevated TDS levels. Further study using strength of evidence, regression analysis and manipulation of laboratory formulated media, indicated that the mine effluent was the primary causal agent of the observed biotic impairment, and its toxicity could be attributed to sodium/sulfate-dominated TDS, which is significantly ameliorated by water hardness. Finally, although testing with lentic cladocerans, such as Ceriodaphnia, is consistent, cost-effective and sensitive to TDS related toxicity, the ecological relevance and protective capability of such testing is questionable when assessing contaminant effects on sensitive macroinvertebrates indigenous to lotic systems. A more ecologically relevant laboratory bioassay using the mayfly, Isonychia bicolor, in simulated lotic microcosms provided more sensitive endpoints than Ceriodaphnia and Pimephales promelas. Although the heartiness of Isonychia in laboratory conditions is poorly understood relative to standardized test organisms, these results, along with potential toxic impacts from numerous sodium/sulfate-dominated wastewaters discharging into freshwater systems, may have important implications to future national pollution discharge and elimination system (NPDES) permit testing. Currently, however, strong recommendations can only be made using Ceriodaphnia endpoints. Potential acute toxicity to aquatic organisms in high hardness solution (~790 mg/L as CaCO₃) is possible where sodium/sulfate-dominated TDS levels exceed ~7000 uS/cm (5167 mg/L), with potential chronic toxicity occurring at ~3200 uS/cm (2342 mg/L). These endpoints were significantly reduced in solutions of lower hardness (88 mg/L as CaCO₃), with acute and chronic toxicity occurring at 5100 uS/cm (3754 mg/L) and ~2100 uS/cm (1523 mg/L), respectively. Point source discharges causing instream TDS concentrations to exceed these levels risk impairment to aquatic life. / Master of Science
7

Hydrologic and hydrochemical processes on mine spoil fills

Clark, Elyse V. 26 April 2017 (has links)
Appalachian surface coal mining operations fracture rocks (termed mine spoils), resulting in the weathering of minerals and release of water-soluble ions to streams. Collectively, the concentration of water-soluble ions in streams is called total dissolved solids (TDS) and streams with elevated TDS often have altered biota. The surficial, subsurface, and discharge properties of mine spoils influence TDS discharge concentrations. This study aimed to improve understanding of how hydrologic and hydrochemical processes occur and function in coal mining areas. These processes were characterized by infiltration and dye staining tests, mine spoil leaching experiments and modeling, and mining-influenced stream discharge monitoring. Results indicate that many factors influence hydrologic and hydrochemical processes in Appalachian coal mining areas, but these processes evolve over time as subsurface flow paths develop, mine rocks weather, and TDS is released from mine spoils. Fourteen years after placement, mean infiltration rates of mine soils reclaimed with trees were statistically greater than areas reclaimed with grasses, and different subsurface flow types were evident, indicating vegetation type influenced hydrologic processes. Specific conductance (SC) leaching patterns from mine spoils conformed to an exponential decay and linear segmented regression model. Maximum SC values (1108 ± 161 µS cm⁻¹) occurred initially during leaching, exponentially decayed, then exhibited linear SC releases (276 ± 25 µS cm⁻¹) that were elevated relative to natural background levels at the end of leaching. Major element (S, Ca, Mg, K, Na) leaching patterns resembled those of SC, whereas trace elements (As, Cd, Cu, Ni, Pb, Se) transitioned to linear release earlier in the leaching period. Mining-influenced stream SC discharge patterns varied by season and by precipitation amounts during storm events. Storm responses were characterized by either infiltration-excess overland flow or delayed SC releases due to internal flow through the VF. Given these results, mining companies wishing to control TDS discharges may be selective and pre-test mine spoils for total S and paste SC to determine TDS-generation potential. Isolation of spoils with high-TDS release potentials (i.e. unweathered sandstones and mudstones) from water-rock contact may help improve TDS discharges. / Ph. D. / The Appalachian surface coal mining process removes rock from above a coal seam by fracturing it with explosives. The fractured rock is then used to reconstruct the original shape of the mountain, and any rock left over after that reconstruction is often placed adjacent to the mining area in landforms constructed to direct water from the mine site to a natural stream. During the mining process, the minerals in the rocks rapidly break down, and when rainwater causes the weathering products (e.g. elements such as calcium, magnesium, sulfur, selenium, and arsenic) to discharge to a stream, the aquatic ecosystem of that stream is usually affected. The objective of this study was to characterize the processes occurring in coal mining areas that ultimately influence the water quality discharged by the mine. Results indicate that many factors influence how rainwater travels through coal mining rocks and the eventual quality of waters discharged from mine rocks, and that these factors evolve over time. A study of 14-year-old mine soils indicated that the type of vegetation (i.e. trees vs. grass) planted after mining influences how water infiltrates into soils and the pathways water travels through once infiltrated. Laboratory studies of mine rocks found that many of those rocks conformed to a single mathematical model that described their elemental release patterns. The model indicated that the quality of waters discharged from mining areas is elevated above natural conditions in the initial phase after mining. Those levels appear to decline over time, but may still have long-term effects on aquatic ecosystems. Field studies of five mining-influenced streams also found that the water quality in those streams was above levels which are detrimental to aquatic ecosystems at all flow levels. It may be helpful to mining companies to test mine rocks prior to mining to determine the best location to place the rocks after mining for mitigation of water quality issues. Isolating mine rocks with the highest potentials to impact water quality may improve post-mining water quality effects.
8

Effect of Hydraulic Fracturing Waste in Wastewater Treatment Processes

Ghasemzadeh, Shahram, M.S. 20 October 2016 (has links)
No description available.
9

Temporal Dynamics of Benthic Macroinvertebrate Communities and Their Response to Elevated Specific Conductance in Headwater Streams of the Appalachian Coalfields

Boehme, Elizabeth A. 27 August 2013 (has links)
Prior studies have demonstrated Appalachian coal mining often causes elevated specific conductance (SC) in streams, and others have examined SC effects on benthic macroinvertebrate communities using point-in-time SC measurements. However, both SC and benthic macroinvertebrate communities exhibit temporal variation. Twelve Appalachian headwater streams with minimally impacted physical habitat and reference-quality physicochemical conditions (except elevated SC) were sampled ten to fourteen times each for benthic macroinvertebrates between June 2011 and November 2012. In situ loggers recorded SC at 15-minute intervals. Streams were classified by mean SC Level (Reference 17-142 S/cm, Medium 262-648 S/cm, and High 756-1,535 S/cm). Benthic macroinvertebrate community structure was quantified by the Virginia Stream Condition Index and other metrics. Structural metric differences among SC Levels and month of sampling were explored. Reference-SC streams exhibited significantly higher scores on most metrics, supporting previous findings that SC may act as a biotic stressor, even in streams lacking limitations from degradation of physical habitat or other physicochemical conditions. Temporal variation was greatest in Medium-SC streams, which had the most metrics exhibiting significant differences among months and the greatest range of monthly means for six metrics. Metrics involving % Plecoptera and/or % Trichoptera were not sensitive to elevated SC, as Leuctridae and Hydropsychidae exhibited increased abundance in streams with elevated SC. Best scores for benthic macroinvertebrate community metrics differed based on selected metric, SC Level, and month. Consequently, timing of sampling is important, particularly in streams with elevated SC because community metric scores may be impacted by dominant taxa life history patterns. / Master of Science
10

An Ecotoxicological Evaluation of Active Coal Mining, Sedimentation and Acid Mine Drainage in Three Tributaries of the Leading Creek Watershed, Meigs County, Ohio

Latimer, Henry Augustus II 20 May 1999 (has links)
Three streams (Parker Run, Little Leading Creek and Thomas Fork) in the Leading Creek watershed, Meigs County, Ohio were impacted by active coal mining, agricultural and abandoned mined land sedimentation and acid mine drainage (AMD), respectively. An ecotoxicological evaluation was performed using physical (water chemistry and sediment depth analyses), toxicological (acute water column, chronic sediment and 35-day in situ toxicity tests) and ecological (benthic macroinvertebrate community sampling) parameters. Persistent acute toxicity (mean 48-hr LC50 of 30.3% to C. dubia) due to low pH (mean of 5.4) and high concentrations of dissolved metals (ex: Al ~ 10 mg/L) were responsible for the significantly depressed benthic macroinvertebrate community sampled in Thomas Fork. Heavy sedimentation (>30 inches), with no associated toxins, significantly decreased both abundance and diversity of benthic macroinvertebrates in Little Leading Creek. High concentrations of sodium (mean of 910 mg/L), TDS (mean of 3,470 mg/L), and periodic acute water column toxicity (mean C. dubia survival of 62% in 100% sample) were most likely responsible for the depressed benthic macroinvertebrate community observed in Parker Run. In ranking the severity of impacts, AMD was first followed by non-toxic sedimentation, and active coal mining ranked last. A catastrophic coal slurry spill significantly impacted the benthic macroinvertebrate community in Parker Run in April 1997. Six sampling stations were established to monitor the recovery of the stream's benthic community and evaluate any impact the active coal mine effluent had on the recovery time of the community. The effluent, characterized by high concentrations of TDS (~4,200 mg/L), significantly hindered benthic macroinvertebrate community recovery in Parker Run. The benthic community at the initial spill site, which was above the active mine effluent, recovered to levels measured at an upstream reference within 4-9 months. Benthic communities impacted by both the slurry spill and the effluent still had not recovered 16 months after the spill. Concentrations of TDS measured in the stream were significantly correlated (r = -0.765 and -0.649 respectively) with both EPT richness and percent C. dubia survival in water column toxicity tests. Laboratory analysis of synthetic coal mine effluent, similar in composition to that of the Parker Run effluent, was performed to determine toxicity thresholds for sodium, sulfate, TDS and conductivity. Acute toxicity thresholds were found for sodium (between 900 and 1,000 mg/L), TDS (4,200 and 6,400 mg/L), and conductivity (5,000 and 6,200 µmhos/cm). It was also determined that any toxic contribution of sulfate in solution with high concentrations of sodium (~1,000 mg/L) and/or TDS (~4,200 __ 6,400 mg/L) was secondary to that of the toxic effect of sodium or TDS in that solution. / Master of Science

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