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Phosphorus Retention and Fractionation in Masonry Sand and Light Weight Expanded Shale Used as Substrate in a Subsurface Flow Wetland

Description: Constructed wetlands are considered an inefficient technology for long-term phosphorus (P) removal. The P retention effectiveness of subsurface wetlands can be improved by using appropriate substrates. The objectives of this study were to: (i) use sorption isotherms to estimate the P sorption capacity of the two materials, masonry sand and light weight expanded shale; (ii) describe dissolved P removal in small (2.7 m3) subsurface flow wetlands; (iii) quantify the forms of P retained by the sub… more
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Date: August 2002
Creator: Forbes, Margaret G.
Item Type: Refine your search to only Thesis or Dissertation

Removal of selected water disinfection byproducts, and MTBE in batch and continuous flow systems using alternative sorbents.

Description: A study was conducted to evaluate the sorption characteristics of six disinfection byproducts (DBPs) on four sorbents. To investigate sorption of volatile organic compounds (VOCs), specially designed experimental batch and continuous flow modules were developed. The investigated compounds included: chloroform, 1,2-dichloroethane (DCE), trichloroethylene (TCE), bromodichloromethane (BDCM), methyl tertiary butyl ether (MTBE), bromate and bromide ions. Sorbents used included light weight aggregate… more
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Date: December 2002
Creator: Kadry, Ahmed Y.
Item Type: Refine your search to only Thesis or Dissertation
open access

Revisiting Aldo Leopold's "Perfect" Land Health: Conservation and Development in Mexico's Rio Gavilan

Description: The Rio Gavilan watershed, located in Mexico 's northern Sierra Madre Occidental , has significance in conservation history. Upon visiting the remote, largely un­developed watershed during two hunting trips in the 1930s, renowned conservationist Aldo Leopold thought it was the best picture of land health he had seen. His main indicators of healthy land were slow water runoff rates regulating erosion and historical predator-prey relationships. The visits confirmed Leopold's concept of land h… more
Date: December 2004
Creator: Forbes, William
Item Type: Refine your search to only Thesis or Dissertation

Riparian Forest Width and the Avian Community in a Greenbelt Corridor Setting

Description: The forest avian community of the Ray Roberts Greenbelt (Denton Co., Texas) was characterized for two years using point count station sampling, from fall 1998 to summer 2000. Richness data for both breeding seasons were correlated with two-spatial metrics: width of the riparian forest and distance to the nearest edge. There were significant correlations between forest interior species richness and both spatial metrics, for both breeding seasons. Based on these data, a minimum riparian forest wi… more
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Date: May 2001
Creator: Hoffman, Karl W.
Item Type: Refine your search to only Thesis or Dissertation
open access

Simulation of physical and chemical processes in reservoirs: Two case studies.

Description: Managing water quality aspects requires the use of integrative tools that allow a holistic approach to this problem. Water quality models coupled to hydrodynamic models are these tools. This study presents the application of the water quality model WASP coupled to the hydrodynamic model DYNHYD for two distinct reservoirs: Lake Texoma and Tocoma Reservoir. Modeling the former included simulations of water velocities, water level, and four chemical and physical compounds: chlorides, dissolved oxy… more
Date: December 2005
Creator: García Iturbe, Selma L.
Item Type: Refine your search to only Thesis or Dissertation
open access

Storm Water System Monitoring for the Small Municipality Under Phase II of the National Pollutant Discharge Elimination System

Description: Storm water quality can have a significant impact on receiving water bodies. The chief recipients of these impacts are aquatic life in the receiving water body and downstream water users. Over the last few decades, legislation, regulations, institutions and facilities have evolved to recognize the impact of urban storm water on receiving streams. This increased emphasis has caused contaminants in storm water to be identified as a major concern. This developing concern has generated an increased… more
Date: August 2003
Creator: Peacock, Steven
Item Type: Refine your search to only Thesis or Dissertation
open access

Thresholds in avian communities at multiple scales: Relationships between birds, forests, habitats, and landscapes in the Ray Roberts greenbelt, Denton

Description: Environmental management agencies make efforts to reduce pollution loading in streams and rivers by promoting vegetated buffer zones between human activity and water. Most of these efforts do not mesh water quality-based buffer zone width requirements with conservation and wildlife values, specifically, the use of these riparian forest corridors for wildlife dispersal between habitats in highly fragmented landscapes. Forest interior birds are of the most concern to management in riparian forest… more
Date: December 2000
Creator: Barry, Dwight
Item Type: Refine your search to only Thesis or Dissertation
open access

Use of geographic information systems for assessing ground water pollution potential by pesticides in central Thailand

Description: This study employed geographic information systems (GIS) technology to evaluate the vulnerability of groundwater to pesticide pollution. The study area included three provinces (namely, Kanchana Buri, Ratcha Buri, and Suphan Buri) located in the western part of central Thailand. Factors used for this purpose were soil texture, percent slope, primary land use, well depth, and monthly variance of rainfall. These factors were reclassified to a common scale showing potential to cause groundwater co… more
Date: August 2002
Creator: Thapinta, Anat
Item Type: Refine your search to only Thesis or Dissertation
open access

Water Quality Aspects of an Intermittent Stream and Backwaters in an Urban North Texas Watershed

Description: Pecan Creek flows southeast through the City of Denton, Texas. Characterized as an urban watershed, the basin covers approximately 63.5 km2. Pecan Creek is an intermittent stream that receives nonpoint runoff from urban landuses, and the City of Denton's wastewater treatment plant, Pecan Creek Water Reclamation Plant, discharges effluent to the stream. Downstream from the City of Denton and the wastewater treatment plant, Pecan Creek flows about 6,000 m through agricultural, pasture, and for… more
Date: August 2002
Creator: Taylor, Ritchie Don
Item Type: Refine your search to only Thesis or Dissertation
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