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Carbon and nitrogen mineralization in wetland soils of the Canadian PrairiesDedzoe, Christian Dela 24 September 2010 (has links)
Wetland soils form an integral part of the agricultural hummocky landscape in the Canadian Prairies. These soils sequester carbon and can serve as sources of greenhouse gases. Three distinctly different but contiguous soils Humic Luvic Gleysols (HLG), Eluviated Dark Brown Chernozems (EDBC) and Calcareous Dark Brown Chernozems (CDBC) located in the St. Denis National Wildlife Area (SDNWA) in four wetlands were selected for study with the aim of comparing the carbon (C) and nitrogen (N) mineralization parameters and determining soil-related factors that influence C and N mineralization in these soils. A short-term aerobic incubation study (16 d) was conducted to determine C mineralization. Nitrogen mineralization was examined using two soil N availability indices: nutrient supply rate (NSR) in a short-term incubation study (14 d) and aerobic leaching-incubation in a long-term study (16 wk). A first order model using non-linear least squares regression was fitted to cumulative C and N curves to determine C and N mineralization parameters (C mineralization potential, Co and C mineralization rate constant, kC; N mineralization potential, No and N mineralization rate constant, kN) for each soil type. Mean cumulative C mineralization, Co, mean cumulative N mineralization and No were highest in the surface horizons and decreased with depth in all the soils. The mean cumulative CO2 production values for the surface horizons were > 150 mg CO2-C kg1 soil while the lower horizon values were < 80 mg CO2-C kg1 soil. Surface mean cumulative N mineralization values were between 5 mg N kg1 soil and 10 mg N kg1 soil with the lower horizons being < 5 mg N kg1 soil. The pattern was similar for Co and No in the surface horizons with values ranging from 200 mg CO2-C kg1 soil to > 300 mg CO2-C kg1 soil and from 8 mg N kg1 soil to 28 mg N kg1 soil, respectively. Nutrient supply rate also showed a similar pattern. The clay fraction showed a stronger negative correlation with the C mineralization parameters in the CDBC than in the other two soils. Organic C and N showed a highly significant positive correlation with almost all the mineralization parameters in all the soils. Overall, notwithstanding the differences in pedogenetic characteristics of the three soils, few significant differences were observed when their C and N mineralization assays were compared. The similarity in the biochemical characteristics of the soils suggests that the observed pedogenic differences do not reflect significantly in the C and N mineralization. Although the pedogenic differences are large, the effects of these differences on soil management are not agronomically significant and the soils can be managed together.
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The Study of Phytoremediation of Oil SpillContaminated Wetland SoilLin, Hung-ta 21 July 2004 (has links)
In this study we used the phytoremediation techniques to treatment diesel contaminated wetland soil. At first, we compared the four common wetland plants, Typha orientalis Presl, Cyperus malaccensis, Bolbos choenus planieulmis and Phragmites communis, on the treatment efficiency of the diesel contaminated wetland soils. From the results, we find out that the Typha orientalis Presl has highest growth rate and activity on rhizosphere among the four species.
The Typha orientalis Presl was planted on artifical diesel contaminated wetland soil and incubated inside a greenhouse, while a control system without vegetation is compared. After 240 days, the result shows that soil planted with Typha orientalis Presl can enhance the microbial and dehydrogenase activity. And adding with nutrients can help plants to prevent the diesel stress. Finally, we utilized the PCR/DGGE methods to analyze soil microbial diversity. According to the DGGE profiles, presence of Typha orientalis Presl can augment microbial diversity .
So far as degradation of TPH-d to be concerned, because of the period was too short, it doesn¡¦t have significant difference between treatments. However, presence of Typha orientalis Presl and addition of nutrients, the TPH-D degradation rate was measured to be approximately 80 % and concentration of TPH-D could degrade from 16000 mg kg-1 to 3500 mg kg-1 after 240 days.
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The Benefits Assessment of People¡¦s Participation in Ecotourism -Take Example of Tanbian Village¡¦s Eco-gardenOu, Fu-Chiang 13 July 2006 (has links)
Abstract
This research aimed to apply the theory of environmental benefits valuation to assess the plan of reformation in Tanbian village¡¦s wetland. Environmental change affects economy. Therefore, through people¡¦s feedback and tourists¡¦ participation of ecotourism, this paper discussed the economic benefits in transforming Tanbian village¡¦s wetland into an eco-garden. Thus, the research adopted the Payment-card method of the Contingent Valuation Method (CVM), categorized under the Non-market Valuation Techniques (NVT), analyzing the economic benefits of eco-tourism¡¦s virtual market at Tanbian village. That is, the amount of people¡¦s Willingness to Pay (WTP) was analyzed to discover the project¡¦s multiple values. Further more, by comparing and contrasting people¡¦s background information, people¡¦s data and differences among other facets were discovered. Finally, in responding to the urgent need in tourism development, this paper integrated tourists and residents¡¦ data to discover the amount of WTP. Such research mode provided a tourism benefits assessment of Tanbian village¡¦s eco-garden project, and its conclusion supplied some suggestions to government control and also future plans of the eco-garden.
There are 239 respondents (including 122 residents and 117 tourists) willing to take the questionnaire survey assuming the correspondence among people¡¦s background information (resident or tourist), attitude and other variables and WTP. After analysis, the result demonstrates that sex and age have little effect on many variables. On the other hand, people¡¦s background (resident or tourist), education level, average income do have obvious influence. However, the both results are valid, showing the principle this research applied is reliable.
The CVM results included:
1. Up to 91.4% People shows positive attitude toward the ten facets of Tanbian eco-garden tour.
2. The average accommodation rates for visitors willing to pay for Tanbian eco-tour is 1,100 NT dollars. And each year, 250NT dollars donation per person can be expected.
3. The average amount of willingness to pay for people to join in an eco-tour is: 118.2NT dollars for eco-tour; 105.5NT dollars for fishing village experience; 60.8NT dollars for farm life experience, 284NT dollars in total.
4. The potential tourism benefits of Tanbian eco-garden are about: 22,098,000NT/year for tourists and 4,236,000NT/year for residents, that is, 26,334,000NT dollars in sum.
5. The eco-garden is around 20 hectares. And the average annual economic benefits per hectare of the wetland were 1,316,000 NT dollars. The estimated benefits were more than the expected value of 250,000NT dollars that the landowners can gain from the wetland today. Therefore, it is feasible to develop ecotourism at this area.
In the end, this research hoped to tribute some advices to Tanbian eco-garden¡¦s management, turning ecological resources into financial sources, for Penghu County to be an ecotourism paradise.
Keywords: wetland, eco-garden, ecotourism, benefits assessment,
Contingent Valuation Method
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Study on the treatment of sewage mixed with partially-treated swine wastewater by a combined upflow anaerobic sludge blanket and constructed wetland processLee, Hsin-Yi 27 June 2007 (has links)
A system with the combination of upflow anaerobic sludge blanket (UASB) reactor and constructed wetlands (CWLs) has not yet been applied for cleaning river water polluted by sewage and swine wastewater. In this study, a pilot system with an UASB reactor (effective working volume 2.5 liters) combined with two CWL reactors (effective working volumes 54.4 and 80 liters for CWL-1 and CWL-2, respectively) was used to test the feasibility for treating wastewater samples prepared by mixing 1 volume of sewage and 1 volume of partially-treated swine wastewater. In the system, the UASB reactor was seeded with an anaerobic sludge for sewage treatment and CWL-1 and CWL-2 were planted with emergent macrophyte (reed, Phragmites australis L.) and floating macrophyte (Pistia stratiotes L.), respectively.
Effects of hydraulic retention time (HRT) of the test wastewater in the UASB reactor on the removal efficacy of various pollutants were tested. HRTs of 6, 4, and 2 hours were set for the UASB for the first, second, and third experimental phases, respectively.
The tested influent wastewater had the following properties (unit in mg/L and the number in parentheses indicates the average value): total CODt 64-332 (179), soluble CODS 28-267 (129), soluble BODS 8-120 (70), SS 110-1330 (372), NH3-N 20-99 (48), NO3--N 1.2-11.9 (2.7), NO2--N 0-3.4 (1.0), total nitrogen TN 24.3-95.7 (56.8), PO43--P 0-10.4 (2.9), total phosphorus TP 5.1-52.1 (23.9), Cu 0.0-0.41 (0.13), Zn 0.05-0.73 (0.27), DO 0.2-2.7 (0.7), and pH 6.9-7.7 (7.4).
Effluents from the UASB reactor for the third phase test had average values of CODt 55, CODS 40, BODS 27, SS 93, NH3-N 42, NO3--N 2.6, NO2--N 0.5, TN 43.7, PO43--P 0.9, TP 17.2, Cu 0.08, Zn 0.07, DO 0.04, and pH 7.4. For the phase, effluents from the combined UASB-CWL1-CWL2 system had average values of CODt 21, CODS 16, BODS 10, SS 38, NH3-N 2, NO3--N 1.9, NO2--N 0.1, TN 11.3, PO43--P 2.6, TP 5.9, Cu 0.06, Zn 0.05, DO 5.4, and pH 7.6. The system has been shown to be economically and technically feasible for cleaning the test wastewater.
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Performance of a 10000 m3/day Constructed Wetland for Treating Polluted River WaterTsai, Shiang-an 13 July 2007 (has links)
The Wu-Luo River located in the Ping-Tong County of southern
Taiwan has long been polluted by untreated domestic and partially treated
poultry wastewaters and is among the most polluted rivers in Taiwan. A
full-scale constructed wetland (CW) has been in operation since January
of 2005 for cleaning a part of the polluted river water. The purpose of
this study was to investigate the specifications of the CW and its
performance for removing both organic and inorganic pollutants form the
influent water.
Results indicate that during the investigation period of April 2006 to
February 2007, the CW had channel widths of 86-112 m (average 100 m)
and a zone-type length of 1,600 m. It occupied a total area of 18
hectares in which around 9 hectares were wetted by the introduced river
water. Around 4.7 hectares of the CW was flooded by the river water
and 1.9 hectares were occupied by emergent and floating plants such as
cattail, water lettuce, reed, water celery, and bara grass. A total water
volume of around 6,800 m3 was estimated. In the period, 10,000-20,000
m3/day (CMD) (average 10,800 CMD) of the polluted river water was
introduced to the CW and a hydraulic retention time (HRT) of 0.63 day
was estimated for the flowing water in the through the water body.
Results also indicated that the influent water has the following
qualities (unit in mg/L except pH and number in parentheses indicates the
average value): total COD (CODt) 10-121 (52), BOD 6-36 (21),
suspended solids (SS) 10-165 (70), pH 5.4-8.1 (7.4), ammonia-N 2-22
V
(13), nitrate-N 0-9.4 (2.5), nitrite-N 0-1.8 (0.2), total-N (TN) 9.9-41.3
(22.6), phosphate-P 0-3.1 (0.9), total-P (TP) 1.2-36.7 (5.2), Cu 0.022-0.60
(0.071), and Zn 0.01-0.36 (0.13). It was found that water sampled from
nearly the middle point of the CW got better clarification results than that
from the effluent end. Pollutant removal efficacies were 60, 60, and
67%, respectively, for CODt, BOD, and SS at the middle point, while 56,
54, and 45%, respectively, for CODt, BOD, and SS at the effluent end.
Organics, N, and P released from rotten plants were responsible for the
poor water qualities at the end. The CW had only a TN removal
efficacy of around 18% and no TP removal effect.
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The response of vegetation to chemical and hydrological gradients in the IMI fen, Henry County, IndianaHess, Benjamin Robert. January 2009 (has links)
Thesis (M.S.)--Ball State University, 2009. / Title from PDF t.p. (viewed on Nov. 30, 2009). Includes bibliographical references (p. [42]-45).
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Characterization of wetland soils in the Beaver Creek WatershedStephens, Kyle, January 2003 (has links)
Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains vi, 131 p. : ill. (some col.), col. map. Vita. Includes abstract. Includes bibliographical references (p. 69-74).
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An Assessment of a Wetland-Reservoir Wastewater Treatment and Reuse System Receiving Agricultural Drainage Water in Nova ScotiaHaverstock, Michael James 13 September 2010 (has links)
A wastewater treatment and reuse system consisting of a tile drainage system, a constructed treatment wetland (CTW), a reservoir, and an irrigation system was established. The system supplied 780 mm of irrigation water for the 1.8 ha of drained land for the 2008 growing season. A hydraulic tracer study conducted in the CTW supported the use of a length to width ratio of 10:1. During 2008, annual nitrate-nitrogen (NO3--N) and Escherichia coli (E. coli) mass reductions were 67.6 and 63.3%, respectively. Elevated E. coli levels were observed in the reservoir during the warm season. Therefore, water may not be safe for irrigating crops consumed raw. The mean first-order areal uptake rate constants generated for NO3--N and E. coli were 8.0 and 6.4 m y-1, respectively, and are recommended for similar CTWs. A wetland area to drainage area ratio of 4.5% is recommended to achieve ? 70 % mass reduction of NO3--N and E. coli
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Pterocarpus officinalis Dominated Wetlands and Dependent FaunaToledo Rodriguez, Frances 16 December 2013 (has links)
Pterocarpus officinalis dominated forests are a rare ecosystem, found only in fifteen locations in Puerto Rico, all of which are adjacent to the coast and at risk from sea level rise, as well as nutrient pollution, upstream hydrological modifications, and deforestation. All forests of this type that were located further inland were destroyed by agricultural development during the early decades of the 1900’s, in particular to grow sugarcane. Prior to this study, there was little information on the diversity of organisms that live in these forests. The central objective of this proposal was to examine the diversity and species composition of three Pterocarpus forests in Puerto Rico located near Humacao, Patillas, and Dorado, and to compare and contrast diversity among the three forests, and identify possible differences caused by human impacts or natural factors. The data was collected through surveys and sampling at each location. Transect surveys, plots, pitfall traps, insect traps and audio recordings were carried out to identify organisms including birds, mammals, amphibians and reptiles, insects, mollusks, invertebrates, plants and fungi.
The Dorado Pterocarpus forest is the most rich and diverse in terms of organisms and has the highest amount of native and endemic species, while the Humacao Pterocarpus forest is the least rich and diverse. Yet conversely, the Dorado forest is the smallest forest, covering only 2.4 ha, while Humacao is the largest, with an area of 150 ha that comprises 63% of the total Pterocarpus coverage in Puerto Rico. The most obvious factor influencing richness and diversity among the forests is the adjacent land cover and history of the sites. Inflow and water sources may also be a factor that alters richness and diversity. This knowledge will assist in the appropriate management of this rare resource in the context of ongoing sea level rise, climate change, nutrient pollution, upstream hydrological modifications, and deforestation. Coastal managers need this information to manage and protect these valuable and rare ecosystems.
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The influence of bacteria on the stability, speciation and mobility of arsenic in contaminated sediments at Terra mine, N.W.T., CanadaDRYSDALE, JESSICA ANN 05 July 2011 (has links)
Terra mine is an abandoned copper and silver mine in the Northwest Territories, Canada, from which mine tailings were deposited into Ho-Hum Lake, adjacent to the mine’s processing plant. The tailings contain elevated levels of arsenic (As), resulting in As levels exceeding Canadian sediment and water quality guidelines in the lake, and in downstream wetland water and sediment. This field and laboratory study focuses on the microbial ecology, and the reduction and oxidation of As, iron (Fe) and sulphur (S), in the wetland downstream from Ho-Hum Lake. This wetland is proposed as a passive remediation system for removal and storage of As.
Using microcosm experiments, the stability of As-bearing sediments was compared in the upper, middle and lowestmost areas of the wetland over a 42-day period. Fresh sediments and sediments amended with a 10 mM acetate solution, both mixed with water, were compared. While no significant geochemical differences were found between acetate-amended and unamended microcosms, formation of inorganic As-S species was higher in amended microcosms, suggesting that micro-organisms were more active in the system because they were not carbon-limited. Formation of methylated-As species increased over time in all samples, including abiotic controls. Bacterial sulphate reduction occurred during the first 10 days of the experiment, perhaps resulting in precipitation of sulphide minerals. X-ray adsorption near edge spectroscopy was used to assess solid-state speciation of As in the sediments and indicated that pre-microcosm sediments from all sites showed high proportions of As(III)-S and As(III)-O speciation. Post-microcosm sediments revealed a 13% increase in the proportion of As(V)-O species, whereas abiotic controls showed only an 8% increase. DNA sequencing in post-microcosm sediments identified As, Fe and S reducing bacteria, and the geochemical patterns of As, Fe and S in the microcosms indicate the bacteria are likely active in the system.
Microbial diversity and solid-state speciation of As in the sediments were assessed at varying depths at the microcosm sites, but correlation analysis revealed no significant relationship between As speciation and microbial diversity. A positive correlation between diversity and depth, and a negative relationship between As concentration and diversity, were found, perhaps indicating decreasing contamination with depth in the wetland. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2011-07-03 23:27:44.373
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