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Thesis
Nitrogen removal from wastewater by an aerated subsurface flow constructed wetland
University of Iowa
Master of Science (MS), University of Iowa
Spring 2012
DOI: 10.17077/etd.jd4ll2e7
Abstract
<p>The purpose of this research was to assess the ability of subsurface flow wetlands, with aeration and vegetation, to remove nitrogen in cold weather climates. Aeration was shown to enhance the wetland cell's ability to remove not only nitrogen but also CBOD, COD, and phosphorus (retention) more effectively. There was a significant difference (p< 0.05) in both total nitrogen and ammonia effluent concentrations comparing aerated to unaerated wetland cells, while no significance was found comparing planted and unplanted wetland cells. The effluent ammonia concentrations from the aerated wetland cells ranged from 2.7 to 5.7 mg N/L, while for unaerated cells effluent concentration ranged from 22 to 23 mg N/L. The effluent total nitrogen concentrations from the aerated wetland cells ranged from 9.0 to 12 mg N/L, while those from unaerated cells ranged from 23 to 24 mg N/L. The effluent concentrations showed no significant difference (p < 0.05) when comparing results of three temperature ranges. There is a correlation when comparing ammonia mass removal rates to mass loading rates. Ammonia removal in the aerated wetland cells ranged from 82 to 95%, while unaerated cells ranged from 39 to 45%. The hydraulic retention times ranged from 3.13 to 4.33 days and the tanks-in-series ranged from 1.46 to 2.84. Using this information the wetland cells were modeled using both the TIS and the PkC* models. The k values (PkC* model) of the aerated wetlands for ammonia ranged from 131 to 221 m/d, while the unaerated wetland cells had values ranging from 20.4 to 36.7 m/d. The models appear to show a good prediction of the effluent ammonia concentration for the unaerated cells but the aerated cells show the model does not effectively capture the effects of aeration.</p>
Details
- Title: Subtitle
- Nitrogen removal from wastewater by an aerated subsurface flow constructed wetland
- Creators
- Eric Redmond - University of Iowa
- Contributors
- Gene Parkin (Advisor)Craig Just (Advisor)David Cwiertny (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Civil and Environmental Engineering
- Date degree season
- Spring 2012
- Publisher
- University of Iowa
- DOI
- 10.17077/etd.jd4ll2e7
- Number of pages
- 91 pages
- Copyright
- Copyright 2012 Eric Redmond
- Language
- English
- Academic Unit
- Civil and Environmental Engineering
- Record Identifier
- 9983776875202771
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