The purpose of this research is to hydraulically characterize an engineered wetland in Albany, Oregon. The wetland receives treated wastewater from both Albany Millersburg Water Reclamation Facility (AMWRF) and ATI Wah Chang. AMWRF's water is municipal waste water. ATI Wah Chang's water comes from its nearby metal processing plant. The wetland is designed to remove thermal input as well as nitrogen species from both sources. ATI Wah Chang effluent has significant nitrate concentrations.
A reliable model is needed to estimate the denitrification potential of the wetland. In order to construct a model, accurate hydraulic parameters such as residence time and flow rate are needed. In the first few days after ATI started flow, the aquatic conductivity level of the wetland increased significantly. Conductivity was used as a tracer to estimate residence times in the wetland as well as to measure the split ratios from different water sources in the wetland (ATI Wah Chang and AMWRF). A pilot test on conductivity and flow rate was carried out on a single pond. The pilot test was designed to accurately measure the influent and effluent from a single pond. Using this information, rates of infiltration as well as unintended flow paths could be identified. A third tracer test was performed using Rhodamine W.T. This test allowed for the determination of the residence time of each pond, the wetland as a whole, and identified stagnant zones within the ponds.
To simulate the nitrogen transportation and transformation process, a numerical model was developed. The model's input parameters include reaction rate constants for nitrification and denitrification, volume of each pond, flow rate, flow path connections, and temperature. The model simulated the tracer test that was performed on the wetland to verify its accuracy. The model is also capable of predicting denitrification potential in both pilot scale and field scale. It is also temperature sensitive because temperatures vary significantly; for instance, in winter when the average temperature in Albany is <5��C, denitrification rates decrease significantly.
Through this research, hydraulic characterization as well as current denitrification rates in the wetland were identified. Strategies for increasing the denitrification rate were also identified through this research. / Graduation date: 2012
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/31342 |
| Date | 08 June 2012 |
| Creators | Huang, Tao |
| Contributors | Dolan, Mark, Kelly, Christine |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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