Thesis (M.S. - Soil, Water, and Environmental Science)--University of Arizona. / Includes bibliographical references (leaves 119-122).

Thesis (M. Env. St.)--University of Adelaide, Mawson Graduate Centre for Environmental Studies, 1993. / Includes bibliographical references (leaves [34-40]).

Thesis (M. Sc.) (Hons)--University of Western Sydney, Hawkesbury, 1994.

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains vii, 69 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xii, 191 p. : ill. (some col.), maps (some col.). Vita. Includes abstract. Includes bibliographical references (p. 117-119).

Thesis (M.S.)--Baylor University, 2006. / Includes bibliographical references (p. 76-77).

Report (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 87-91). Also available via the Internet.

Thesis (M. L. A.)--University of Hong Kong, 2007. / Title proper from title frame. Includes special report study entitled: Constructed wetland for wildlife, drainage and sewage treatment. Also available in printed format.

Constructed wetland treatment systems are environmental-friendly and economic technologies for wastewater treatments. The Dapeng Bay National Scenic Area Administration collected the wastewaters from the salty water aquacultural ponds and community households in the adjacent areas and discharged them into salty water type of constructed wetland treatment systems, which is quite rare in Taiwan presently. According to the surveying result of water quality in these constructed wetland treatment systems in previous study, we found that some species of macroalgae Gracilaria, were existed in some units of the wetland systems. Further, we found that the wastewater treatment efficiencies of the constructed wetland systems could be substantially enhanced by the macroalgae. Reviewing some literatures also confirmed that the macroalgae, Gracilaria, can be effectively applied to aquaculture wastewater treatment because it is able to absorb the nutrients and benefits its own growth. Besides, it can reduce the algal bloom caused by excess nutrients. In this study, we explored the macroalgae Gracilaria¡¦s role in those saline constructed wetland wastewater treatment systems. In the laboratory scale study, a constructed wetland model tank was designed to culture Gracilaria as a way to explore the situation of wastewater treatment. The experimental results showed that when cultured in the still water system, the macroalgae, Gracilaria, was able to increase both of the levels of dissolved oxygen and pH in wastewater. Moreover, when it was cultured in its biomass density of 10 g/L for 4 days, the removal efficiency of chlorophyll-a concentration could ideally reach to 79.10 ¡Ó 7.62 %, while the total nitrogen, and total phosphorus could reach to 47.10 ¡Ó 25.93 % and 60.49 ¡Ó 45.29 % respectively. However, the reduction of ammonia nitrogen concentration was found rather obvious only one day after culture. Whereas, when the species of Gracilaria was cultured in the continuous flow system, we found that there were significant difference in the test result of the turbidity, chlorophyll-a, and BOD in the experimental group with addition of Gracilaria. After testing the concentrutions of chlorophyll-a over a long period of time, we found that the chlorophyll-a concentration were markedly increased when Gracilaria was not added. On the contrary, the chlorophyll-a concentration was remained stably when Gracilaria was added. When it comes to the nitrogen removal, we found that the removal efficiency of ammonia nitrogen in the experimental group could reach up to 92.27 ¡Ó 3.82 % in average. Other than that, it was found obvious decrease of the ammonia nitrogen concentration on the first day of culture. As to the test of soil¡¦s impact on the phosphorus removal, we found that the removal efficiency in the experimental group was higher than the group without soil. Therefore, the removal efficiency was found obviously higher when there was soil. In the continuous flow system, when the species of Gracilaria was added, the removal efficiency of total nitrogen and total phosphorus in the model tank could reach averagely up to 75.23 ¡Ó 2.46 % and 53.96 ¡Ó 11.18 %, respectively. Comparing the experimental results by growth of Gracilaria for water quality with laboratory study and the saline constructed wetland systems in the Dapeng Bay, we found that the removal efficiencies of contaminants and nutrients could be enhanced by Gracilaria.

Treating elevated nutrients, suspended solids, oxygen demanding materials, heavy metals and chemical fertilizers and pesticides in agricultural wastewaters is necessary to protect surface and ground waters. Constructed wetlands (CWs) are an increasingly important technology to remediate wastewaters and reduce negative impacts on water quality in agricultural settings. Treatment of high strength effluents typical of agricultural operations results in the production of methane (CH4), a potent greenhouse trace gas. The objective of this study was to evaluate CH4 emissions from two subsurface flow (SSF) CWs (223 m2 each) treating dairy wastewater. The CWs were implemented at the University of Vermont Paul Miller Dairy Farm in 2003 as an alternative nutrient management approach for treating mixed dairy farm effluent (barnyard runoff and milk parlor waste) in a cold, northern climate. In 2006, static collars were installed throughout the inlet, mid and outlet zones of two CWs (aerated (CW1) and a non-aerated (CW2)) connected in-series, and gas samples were collected via non-steady state chambers (19.75 L) over a nine-month period (Feb-Oct 2007). Methane flux densities were variable throughout the nine-month study period, ranging from 0.026 to 339 and 0.008 to 165 mg m-2 h-1 in CW1 and CW2, respectively. The average daily CH4 flux of CW1 and CW2 were 1475 and 552 mg m-2 d-1, respectively. Average CH4 flux of CW1 was nearly threefold greater than that of CW2 (p = .0387) across all three seasons. The in-series design may have confounded differences in CH4 flux between CWs by limiting differences in dissolved oxygen and by accentuating differences in carbon loading. Methane flux densities revealed strong spatial and seasonal variation within CWs. Emissions generally decreased from inlet to outlet in both CWs. Average CW1 CH4 flux of the inlet zone was nearly threefold greater than mid zone and over tenfold greater than flux at the outlet, while fluxes for CW2 zones were not statistically different. Methane flux of CW1 was nearly fifteen fold greater than CW2 during the fall, representing the only season during which flux was statistically different (p = .0082) between CWs. Fluxes differed significantly between seasons for both CW1 (p = .0034) and CW2 (p = .0002). CH4 emissions were greatest during the spring season in both CWs, attributed to a consistently high water table observed during this season. Vegetation was excluded from chambers during GHG monitoring, and considering that the presence of vascular plants is an important factor influencing CH4 flux, the potential CH4 emissions reported in our study could be greatly underestimated. However, our reported average CH4 fluxes are comparable to published data from SSF dairy treatment CWs. We estimate average and maximum daily emissions from the entire CW system (892 m2) at approximately 1.11 and 6.33 kg CH4 d-1, respectively, yielding an annual average and maximum flux of 8.51 and 48.5 MtCO2-e y-1, respectively.