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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.
121

Visions of a wetland: linking culture and conservation at Lake Manyas, Turkey

Ari, Yilmaz 15 March 2011 (has links)
Not available / text
122

Evaluation of a pilot land-based marine integrated aquaculture system

Boxman, Suzanne 01 January 2013 (has links)
Recirculating aquaculture systems (RAS) produce aquaculture products on land with minimal discharge of waste products and minimal water loss. High costs associated with waste treatment for RAS have triggered the growth of integrated aquaculture systems (IAS) which incorporate macrophytes (aquatic plants) into the treatment train. The objective of this research was to examine a pilot scale inland marine IAS with three different methods for solids treatment: a sand filter followed by a plant bed, only a plant bed, and geotextile bags. Florida Pompano (Trachinotus carolinus) were grown along with Smooth Cordgrass (Spartina alterniflora), Black Needle Rush (Juncus romerianus), and Red Mangrove (Rhizophora mangle). Between May 2011 and April 2012, water quality was tested at seven points located throughout the IAS for total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), ammonium (NH4+), nitrate (NO3-), total phosphorus (TP), and orthophosphate (PO43-) concentrations every 4 to 6 weeks. Plant and soil samples were collected three times and analyzed for total nitrogen and total phosphorus. A statistically significant difference in the effluent concentrations for the three treatments was not found; however, due to the recombination of effluent from the solid treatments and the variability inherent in a pilot scale system it was difficult to isolate the individual efficiencies of each treatment. Therefore, on average the complete system achieved COD and TSS removal efficiency of 59% and 88%, respectively and TN and TP removal efficiency of 48% and 19%, respectively. Nutrient uptake by plants did not vary significantly between the plant beds. In general, the system provided sufficient nutrient removal for safe fish production, and the fish provided enough nutrients for ample plant growth.
123

An investigation into constructed wetlands for domestic greywater treatment and reuse in Ontario

Chan, Carolyn 04 January 2014 (has links)
The reuse of domestic greywater for toilet flushing has the potential to reduce both water consumption and wastewater production, but there is a need for low-cost, low-maintenance greywater treatment systems that can meet reclaimed water quality standards. The purpose of this thesis is to develop a horizontal subsurface flow wetland design that can be sited in a greenhouse, to document the initial performance of the design treating real greywater, to determine the effect of plants, and to provide recommendations for design. Pilot wetlands (planted and unplanted replicates) were constructed in a passively heated greenhouse and fed real domestic greywater. Effluent quality was compared to national reclaimed water quality guidelines. After the first five months of the study, operational changes (reduced loading, aeration of influent, fill and drain) were tested to determine their effect on effluent quality. The results show that the original design basis, 7.5 gBOD m-2d-1, is not appropriate for greywater wetland design under the conditions of this study due to insufficient removal of BOD and turbidity (although suspended solids removal was acceptable). Anoxic conditions within the wetlands led to reduction of sulfate to hydrogen sulfide, which demands oxygen and leads to odour and turbidity problems. Plants did not affect treatment during the first five months. Aerating influent and operation in fill and drain mode may improve BOD removal at relatively high hydraulic loading rates, but effluent disinfection is required to completely remove E.coli. Design recommendations were developed, including tentative loading rates and plant species. / Ontario Centres of Excellence, NSERC
124

Temporal effect on nitrogen removal in a subsurface flow constructed wetland

Hanson, Carter Curtis January 1996 (has links)
A subsurface flow constructed wetland planted with the common reed (Phragmites australis) and softstem bulrush (Scirpus validus) was built in East Central Indiana. The objective of this study was to determine if temperature had an effect on nitrogen (N) removal from the wetland. The research was conducted from the first week of October 3, 1995 to the first week in December 5, 1995 why the wetland froze. Water samples were taken from 5 samplings sites in the system. Each sample was analyzed for organic-N, ammonia, nitrate, and total-N. In the system statistically significant amounts of organic-N, nitrate, and total-N were removed. Ammonia lever reductions, however, were not significant. Organic-N had a mean removal of 37% (8 mg/1) 'Nitrate had a mean removal of 96% (2.3 mg/1). Total-N removal over the sampling period averaged 30% (12 mg/1). The N results were regressed against air and wastewater temperatures. Wastewater temperature was more important because it had a direct impact can the plants and microbes in the system. Warmer temperatures sustained a higher metabolism for the biota in the system. Air temperature had an indirect impact on efficiency of N removal from the wastewater flowing through the wetland. The primary impact .: f the air temperature was on water temperature which then affected the metabolism of or a nc ns in the wetland cell. Greater removal efficiencies were seen during high temperature periods and lower removal efficiencies were noted when the temperatures were low. / Department of Natural Resources and Environmental Management
125

Nitrogen removal and biomass production from a harvested and unharvested scirpus wetland

Schultz, Paul Eaton January 1997 (has links)
A subsurface flow constructed wetland was built at the Wastewater Treatment Plant in Muncie, Indiana, in May, 1995. In May, 1996, this wetland was divided into two equal cells and planted with Scirpus validus vahl (softstem bulrush). Samples were collected from July 30, 1996, through October 22, 1996. This study had two objectives. The first was to determine if harvesting the aboveground biomass of the Scirpus would affect the wetland's ability to remove nitrogen from the wastewater. The second objective of this study was to determine if harvesting the bulrush twice during a growing season would substantially increase the annual biomass production. Water was collected from four locations in each cell and analyzed for organic nitrogen, ammonical nitrogen, nitrate, and total nitrogen. The concentration of each nitrogen parameter was significantly reduced between the inlet and well 1 in each cell of the wetland. There were no significant reductions in nitrogen concentration in subsequent sampling locations. There were also no significant differences between the two wetland cells. / Department of Natural Resources and Environmental Management
126

Evaluating the effectiveness of commercial nitrifying bacteria in a constructed wetland

Smith, Timothy R. January 1996 (has links)
This research was conducted to determine the effects of commercially available nitrifying bacteria in a constructed wetland. The study was conducted at Paws, Inc., near Desoto, Indiana during the summer of 1995. The wetland, called Solar Aquatics Treatment System (SAS), was developed by Ecological Engineering Associates and constructed in a, greenhouse. The commercial nitrifying bacteria (Bacta-Pur), contained Nitrosomonas and Nitrobacter Spp. and have been added to the wetland for the past five years to aid in the removal of nitrogen.Water samples were taken from the wetland and analyzed for ammonia, nitrite, nitrate, dissolved oxygen, hydrogen ion concentrations and water temperature from Monday through Friday for three weeks. A baseline was established from these samples. After three weeks of testing the addition of Bacta-Pur to the wetland was discontinued.To determine whether these additional bacteria were needed, testing without the Bacta-Pur was conducted for three weeks. These samples were collected and analyzed for the same parameters as those used to establish baseline information.Ammonia concentrations were significantly lower without the addition of Bacta-Pur bacteria. There were no significant differences for concentrations of nitrite and nitrate. The water temperature was higher in the three weeks when no Bacta-Pur was added. This was due to the increase in ambient temperature which caused the water temperature in the SAS to increase. Since the nitrogen compounds either remained the same or decreased in concentration at the effluent without the addition of bacteria, the addition of Bacta-Pur is not needed in order to remain in compliance with EPA regulations for effluent standards.A container experiment was conducted to provide an' environment that had no introduced bacteria before the addition of Bacta-Pur. There were no significant differences for the nitrogen compounds between wastewater samples with addition and without addition of Bacta-Pur bacteria. / Department of Natural Resources and Environmental Management
127

The efficiency of constructed wetlands for the removal of the antimicrobial agent triclosan from wastewater

Zinn, Elizabeth R. 15 December 2012 (has links)
Access to abstract restricted until December 2014. / Review of relevant literature -- Efficiency of constructed wetlands to remove an antimicrobial agent triclosan from wastewater -- The removal of triclosan from laboratory scale constructed wetlands with four species of wetland plants -- Additional research : determination of the hydraulic retention time in an operational subsurface constructed wetland -- Additional research methods : the evaluation of the subsurface constructed wetland for the treatment of iron, phosphorus, ammonia, nitrite, nitrate, dissolved oxygen, pH and E. coli. / Access to thesis restricted until December 2014 / Department of Natural Resources and Environmental Management
128

Modelling urban runoff : volume and pollutant concentration of the Barker Inlet Wetland Catchment /

French, Rachel. January 1999 (has links) (PDF)
Thesis (M.Eng.Sc)--University of Adelaide, Dept. of Civil and Environmental Engineering, 2000? / Bibliography :leaves 158-171. A monitoring program, funded by the South Australian government (through the former MFP Development Corporation), was established to monitor the quality and quantity of storm water entering and leaving the wetland. This study formed part of the funded program. Simple regression models were developed; and will assist in the monitoring of performance of the wetland to alleviate the pollutant load into the Barker Inlet.
129

An investigation into the treatment efficiency of a primary pond in the Barker Inlet Stormwater Wetland System, South Australia /

Murphy, Sarah Elizabeth. January 1999 (has links) (PDF)
Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 2000? / Corrigenda pasted onto front end-paper. The CD contains Excel spreadsheets containing data collected. Bibliography: leaves 209-222.
130

Impact of pre-ozonation on distillery effluent degradation in a constructed wetland system /

Green, Jeffrey. January 2007 (has links)
Thesis (MSc)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet.

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