Recovery of the Fish Population of a Municipal Wastewater Dominated, North Texas Creek after a Major Chlorine Disturbance

Recovery of the Fish Population of a Municipal Wastewater Dominated, North Texas Creek after a Major Chlorine Disturbance

Date: August 2002
Creator: Maschmann, Gerald F.
Description: This study evaluated the effects of a major chlorine disturbance on fish communities in Pecan creek by the City of Denton's Pecan Creek Water Reclamation Plant. Fish communities in Pecan Creek were sampled using a depletion methodology during February, April, July, and November, 1999. February and April sampling events showed that the fish communities were severely impacted by the chlorine. Sampling during July and November showed fish communities recovered in Pecan Creek. The first-twenty minutes of shocking and seining data were analyzed to mirror an equal effort methodology. This methodology was compared to the depletion methodology to see if the equal effort methodology could adequately monitor the recovery of Pecan Creek after the chlorine disturbance. It was determined that the equal effort methodology was capable of monitoring the recovery of Pecan Creek, but could not accurately represent the fisheries community as well as the depletion method. These data using the twenty-minute study were compared to a previous study. Results of this study were similar to those found in a previous study, although fish communities were more severely impacted and took longer to recover.
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Phosphorus Retention and Fractionation in Masonry Sand and Light Weight Expanded Shale Used as Substrate in a Subsurface Flow Wetland

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

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Date: August 2002
Creator: Forbes, Margaret G.
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 substrates in the pilot cells; and (iv) use resulting data to assess the technical and economic feasibility of the most promising system to remove P. The P sorption capacity of masonry sand and expanded shale, as determined with Langmuir isotherms, was 60 mg/kg and 971 mg/kg respectively. In the pilot cells receiving secondarily treated wastewater, cells containing expanded shale retained a greater proportion of the incoming P (50.8 percent) than cells containing masonry sand (14.5 percent). After a year of operation, samples were analyzed for total P (TP) and total inorganic P (TIP). Subsamples were fractionated into labile-P, Fe+Al-bound P, humic-P, Ca+Mg-bound P, and residual-P. Means and standard deviations of TP retained by the expanded shale and masonry sand were 349 + 169 and 11.9 ...
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Wastewater Treatment: Overview and Background

Wastewater Treatment: Overview and Background

Date: March 20, 2008
Creator: Copeland, Claudia
Description: The Clean Water Act prescribes performance levels to be attained by municipal sewage treatment plants in order to prevent the discharge of harmful wastes into surface waters.
Contributing Partner: UNT Libraries Government Documents Department
Concentrations of Triclosan in the City of Denton Wastewater Treatment Plant, Pecan Creek, and the Influent and Effluent of an Experimental Constructed Wetland

Concentrations of Triclosan in the City of Denton Wastewater Treatment Plant, Pecan Creek, and the Influent and Effluent of an Experimental Constructed Wetland

Date: August 2004
Creator: Waltman, Elise Lyn
Description: The Pecan Creek Waste Reclamation Plant in Denton, Texas, an activated sludge WWTP, was sampled monthly for ten months to determine seasonal and site variation in concentrations of triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol), an antibacterial additive. SNK separation after the highly significant ANOVA on ranked data were: summer = fall > winter = spring and influent > downstream = effluent = wetland inflow > wetland outflow (a=0.05). After the plant converted to ultraviolet disinfection, measurements were made before and after the UV basin to determine if significant amounts of triclosan were converted to dioxin. Percent loss at each of the treatment steps was determined. Concentrations of triclosan in the downstream site were below the published NOEC for the most sensitive species.
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How Healthy is the Upper Trinity River?: Biological and Water Quality Perspectives

How Healthy is the Upper Trinity River?: Biological and Water Quality Perspectives

Date: 1990
Creator: Jensen, Ric
Description: This conference report contains discussions and papers from a symposium hosted at Texas Christian University, in Fort Worth, Texas, examining the ecological health of the Upper Trinity River, and the impacts of various human activity, such as agriculture, urbanization, and waste management. The papers cover the effect of water quality on urban rivers, long-term water quality trends in the Trinity River, solutions that may improve water quality in the river, as well as biological, agricultural and waste-water issues.
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Pretreatment Optimization of Fiberglass Manufacturing Industrial Wastewater

Pretreatment Optimization of Fiberglass Manufacturing Industrial Wastewater

Date: December 1998
Creator: Dragoo, Ron
Description: Wastewater effluent produced in the fiberglass manufacturing industry contains a significant amount of total suspended solids. Environmental regulations require pretreatment of effluent before it is discharged to the municipal wastewater treatment plant. Chemical precipitation by coagulation and flocculation is the method of pretreatment used at the Vetrotex CertainTeed Corporation (VCT). A treatability study was conducted to determine conditions at which the VCT Wastewater Pretreatment Plant could operate to consistently achieve a total suspended solids concentration ≤ 200-mg/L. Jar tests varied pH, polymer dosage, and ferric sulfate dosage. Total suspended solids and turbidity were measured to evaluate treatment performance. The data were used to determine an optimum set of conditions under project guidelines. Of twelve polymers screened, BPL 594 was selected as the most effective polymer. For cost efficiency in the wastewater pretreatment operation, recommendations suggested that treatment chemical injection be electronically controlled according to turbidity of the treated effluent.
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Conception and Design of Constructed Wetland Systems to Treat Wastewater at the Biosphere 2 Center with Use of Reaction Rate Models and the Habitat Evaluation Procedure to Determine the Effects of Designing for Wildlife Habitat on Treatment Efficiency

Conception and Design of Constructed Wetland Systems to Treat Wastewater at the Biosphere 2 Center with Use of Reaction Rate Models and the Habitat Evaluation Procedure to Determine the Effects of Designing for Wildlife Habitat on Treatment Efficiency

Date: May 1998
Creator: Clingenpeel, Glenn C. (Glenn Christopher)
Description: A study was undertaken to explore relationships between wetland characteristics which make them efficient water purifiers versus their ability to serve as wildlife habitat. The effects of designing constructed wetlands for improved habitat on water treatment efficiencies were quantified. Results indicate that some sacrifice in treatment efficiency is required and that the degree of efficiency reduction is dependant upon pollutant loading rates. However, sacrifice in efficiency is much smaller than increase in habitat quality, and can be offset by increasing wetland area. A practical, theoretical application was then attempted.
Contributing Partner: UNT Libraries