This research addressed the question whether a constructed wetland system with phytoremediation could successfully uptake 1,4-Dioxane in groundwater and secondary effluent. It further addressed whether open pond storage could successfully treat wetland discharge. The project was located at the University of Arizona's Constructed Ecosystems Research Facility (CERF) in Tucson, Arizona. This two-year field study was motivated by previous laboratory studies which demonstrated the capability of plants to remediate the recalcitrant contaminant 1,4-Dioxane.The study was conducted in two open steel tanks configured to simulate constructed wetlands. The efficacy of 1,4-Dioxane uptake by cottonwood trees was tested in a side-by-side comparison utilizing planted and unplanted tanks. The sub-surface hydraulic conditions were fully characterized by bromide tracer studies. Six experiments were conducted, in which tapwater or secondary effluent was spiked with 5.2 mg/L 1,4-Dioxane and fed to the planted and unplanted (control) tank. The tank discharges were retained in separate open ponds to test if open pond storage would reduce 1,4-Dioxane content. Additional side experiments were conducted to examine the role of volatilization and UV degradation. Comparison of 1,4-Dioxane mass discharge from the planted and the control tank demonstrated an 18-48 percent uptake by the cottonwood trees. Mass balance assessments showed 1,4-Dioxane uptake efficiency was positively correlated to cottonwood transpiration rates in the planted tank. The open pond 1,4-Dioxane measurements demonstrated a 64-85 percent reduction in 1,4-Dioxane concentration due to volatilization during the initial 120 hours pond lapse time. Elimination of 1,4-Dioxane from the ponds followed first order kinetics. Field and laboratory side experiments demonstrated the potential for UV photo degradation of 1-4-Dioxane.

Abstract Centro Universitaire UNIVATES is located in the town Lajeado that is situated in the most southerly state, Rio Grande Do Sul, in Brazil. The university has 5000 students, teachers and others staff. UNIVATES is not satisfied with their present wastewater situation and wants to improve it by eliminate the smell caused by the wastewater. They would also like to remove the oil that the storm water brings into the wetland. The high amount of particles in the storm water gives rise to a lot of sediments that eventually will fill up the wetland, and something has to be done about this, if the wetland should continue to be in use. Another aspect to consider is the wish of some people at UNIVATES, for the wetland to be a beautiful and recreational place. All these factors had to be considered, which led to the main question: How can the use of the wetland for wastewater treatment be combined with the request for the wetland to be a beautiful place with the wildlife preserved? During the course Wetland Technology that we took before our departure to Brazil, we got introduced to the situation at UNIVATES by Professor André Jasper and Odorico Konrad who visited the course several times. They pointed out that the main issue is the smell from the wastewater and later during the field study at UNIVATES, more information were obtained through discussions, meetings and conversations with the people involved. Several visual inspections were carried out by walking around the wetland. We could determine where and how the inlets and outlets to the wetland were and when it was clear which inlets that brought wastewater and which that brought storm water, the water flow of the wastewater was estimated. Water samples from the wetland were collected at five different sites and analyses of pH, BOD, COD, N-Tot, phosphorus and metals were done by the accredited laboratory at UNIVATES. To test some of our theories, we did a smaller practical experiment that got the name Superficial Filtration Bed. The results from the water samples showed the highest BOD, COD, N-Tot and Phosphorus levels in the samples from site 2 and 4 and this reveals that it is wastewater. This was also confirmed by the smell that we felt at these sites during the visual inspections. The results also showed that there is no wastewater coming from site 1, 3 and 5. Our final proposal is to create a multifunctional wetland with the purpose to take care of both storm water and wastewater and at the same time work as a research and recreational area. The wetland, which would be divided into two parts, will constitute of all the fundamental functions; storm water buffering, sedimentation basin and biological oil separation and treatment. There will also be research sites and hybrid system for wastewater treatment. The hybrid system will consist of two steps where the first is aerobic and the second both aerobic and anaerobic. The first step is a Superficial Filtration Bed (SFB) and the second a FWS wetland. The conclusion of this thesis is that more detailed research is needed to be able to dimension the specific functions correctly. With some further investigations the proposal presented is possible to carry through and our feeling when we left UNIVATES was that the people responsible really liked our ideas. They made it clear that they want to make a change and improve the situation and with the help they have gotten from us, they are a few steps closer to solving the problem.

No description available.

Jurisdictional ownership of all natural resources, including wetlands and river channels, belongs to the state in Bangladesh, and access to and control over wetland resource are determined by the existing top-down, command-and-control, bureaucratic management regimes. Grounded solely in the economic aspects of natural resources, the wetland management objective of the government focuses on rent-seeking to maximize revenues and other economic benefits. At the operational level, this approach presumes bounded and closed economic and social systems and an equilibrial environment. The purpose of this research was to investigate options for institutionalizing participation of stakeholders in wetland (haor) resource management. It was intended to seek alternatives to the state-governed management approach (SMA) and find a means of governance that would encompass multi-stakeholders in the management of natural resources. The specific objectives of this research were to: i) Examine the state-governed management approach and the relationship between formal and informal institutions concerned with access and control over wetland (haor) resources; ii) Analyze, as an alternative to SMA, the processes and structures of stakeholders’ participation and deliberations in decision-making; and iii) Examine the potential for multi-stakeholder governance in wetland resource management. This research selected three development initiatives in Hakaluki haor (major wetland of Bangladesh) for assessment. A set of PRA methods, which included baseline surveys, focus group discussions, key informant interviews, semi-structured interviews, individual discussion meetings, addah (informal chatting with friends and fellows), and workshops, was used during the research to attain the objective of the study. The research findings have revealed that the community-based organizations (CBOs) were capable of contributing effectively to the community-based or co-management approach in wetland resource management. Establishing a multi-level stakeholder governance system as an institutional structure and process is necessary to sustain CBOs’ operations in decision-making. The participation of local resource users would require appropriate degree of integration of the “bottom-up” and “top-down” approaches to include all relevant stakeholders in the decision-making processes at multiple levels of social organizations. This alternative approach could be an effective instrument to facilitate the deliberations of stakeholders and to strengthen institutional linkages to engender benefits to the local resource users.

Growth room experiments were conducted to examine terrestrial and wetland-based phytoremediation approaches as alternatives to biosolids management. Results from both experiments show that biosolids do not need to be amended with soil to encourage plant growth and optimize biomass yields. In the terrestrial phytoremediation approach, two harvests per growth cycle produced greater switchgrass biomass yield than a single harvest but had no significant effect on cattail biomass yield during the first cycle. Repeated harvesting also significantly increased mean nutrient uptake in Cycle 1, reflecting the greater biomass yield from two harvests compared with a single harvest. In the wetland experiment, nutrient phytoextraction under two harvests was 4.25% of initial N content and 2.28% of initial P content compared with 2.9% and 1.58%, respectively, under a single harvest. Terrestrial phytoremediation could be beneficial to small communities that cannot afford the costly excavation, trucking, and eventual spreading of biosolids on agricultural land.

Phenol oxidases mediate the degradation of recalcitrant compounds, polyphenolics, in wetland soils and are considered to play a key role in the microbial carbon cycle of peatlands which predominate in boreal biomes. In order to validate a method for quantification of oxidative enzyme activity in acidic wetland environments, the relationship between pH and substrate oxidation was studied using the standard enzyme tyrosinase and in soils collected from six freshwater wetlands including three marshes in north Florida and peatlands of northern Minnesota. Phenol oxidase (PO) activity was quantified with two commonly used assay substrates, ABTS (2,2'-azino-bis(3-ethylobenzthiazoline-6-sulfonic acid) and L-DOPA (L-3,4-dihydroxyphenylalanine), across a pH range of 4 to 7 which matched the in situ pH range of the studied wetlands. The PO assay is sensitive and activity could be detected with either substrate across a pH range of 4 to 7. However, with the standard enzyme tyrosinase, it was shown that a large change or threshold in oxidation rates occurred at pH 5. At pH < 5, L-DOPA oxidation rates were greatly diminished and ABTS oxidation was at a maximum. Above pH 5, ABTS oxidation occurred at much slower rates and L-DOPA oxidation was at a maximum. The pH response of PO activity in wetland soils corroborated observations made with tyrosinase. Thus, ABTS is recommended to be an effective substrate for the quantification of PO activity at an in situ pH of < 5, while L-DOPA is recommended at an in situ pH of > 5. In soils collected from a northern Minnesota peatland, assays conducted at an in situ pH of 4 showed one to two orders of magnitude higher rates of PO activity in solid phase peat in comparison to porewater, indicating that the majority of PO activity is associated with the peat. At three Minnesota peatland sites, PO activity was shown to attenuate with depth in agreement with the activities of other enzymes and with rates of peat decomposition.

Jurisdictional ownership of all natural resources, including wetlands and river channels, belongs to the state in Bangladesh, and access to and control over wetland resource are determined by the existing top-down, command-and-control, bureaucratic management regimes. Grounded solely in the economic aspects of natural resources, the wetland management objective of the government focuses on rent-seeking to maximize revenues and other economic benefits. At the operational level, this approach presumes bounded and closed economic and social systems and an equilibrial environment. The purpose of this research was to investigate options for institutionalizing participation of stakeholders in wetland (haor) resource management. It was intended to seek alternatives to the state-governed management approach (SMA) and find a means of governance that would encompass multi-stakeholders in the management of natural resources. The specific objectives of this research were to: i) Examine the state-governed management approach and the relationship between formal and informal institutions concerned with access and control over wetland (haor) resources; ii) Analyze, as an alternative to SMA, the processes and structures of stakeholders’ participation and deliberations in decision-making; and iii) Examine the potential for multi-stakeholder governance in wetland resource management. This research selected three development initiatives in Hakaluki haor (major wetland of Bangladesh) for assessment. A set of PRA methods, which included baseline surveys, focus group discussions, key informant interviews, semi-structured interviews, individual discussion meetings, addah (informal chatting with friends and fellows), and workshops, was used during the research to attain the objective of the study. The research findings have revealed that the community-based organizations (CBOs) were capable of contributing effectively to the community-based or co-management approach in wetland resource management. Establishing a multi-level stakeholder governance system as an institutional structure and process is necessary to sustain CBOs’ operations in decision-making. The participation of local resource users would require appropriate degree of integration of the “bottom-up” and “top-down” approaches to include all relevant stakeholders in the decision-making processes at multiple levels of social organizations. This alternative approach could be an effective instrument to facilitate the deliberations of stakeholders and to strengthen institutional linkages to engender benefits to the local resource users.

No description available.

In the past fire ecology literature in the tropics has focused mostly on the role of fire within the savanna biome. The fire ecology of tropical wetlands has been largely neglected. This thesis attempts to redress this imbalance by examining the fire behaviour of the wetlands in Kakadu National Park, northern Australia. Wetland burning has become a critical management issue in the Park, particularly since the eradication of the feral Asian water buffalo (Bubalus bubalis Linnaeus) from the Park. Fuel loads, which had been previously suppressed by grazing and trampling, have increased substantially, and this has subsequently affected the fire ecology of the region. This thesis investigates aspects of fire ecology in the Mclaleucafloodplain communities of Kakadu. It examines Aboriginal people's contemporary use and knowledge of fire, as well as the fire behaviour and impact of fires both set by Aboriginal people and from other sources of ignition. In addition, a 'Wetland Burning Index' (WBI) is compiled in order to examine some of the interactions between wetland fuel, weather and fire behaviour. A range of ecological and ethnoecological methodologies are employed in order to measure fire behaviour in situ rather than approximating specific fire regimes under experimental conditions. The thesis assesses the effectiveness and practicability of these methods. A description of wetland fire behaviour is also given, and includes a range of fire types and phenomena. Aboriginal names of fires, and related terms, are also detailed (in the Gundjeihmi language), some of which have not been previously documented. The study concludes by discussing how indigenous people's knowledge of fire can contribute to the field of wetland fire ecology. It also discusses how different fire types can be used to manage tropical wetland ecosystems.

Goss Moor NNR is a unique, rare and nationally-important wetland habitat in Mid- Cornwall. The majority of the habitats were created as a result of a long history of tin-stream mining, which ceased in the early 1900s. Phytosociological surveys of poor-fen and willow carr communities provide the first formal descriptions of the vegetation at this site. The poor-fen survey revealed twelve poor-fen vegetation types, which were distributed along a primary environmental gradient of organic matter depth, surface water height and bare substrate. Separation of the poor-fen communities by a moisture gradient was considered as spatial evidence for hydroseral succession, which begins with the colonisation of open-water pools created by tin excavations. The Salix cinerea ssp. oleifolia willow carr was divided by eight understorey communities, according to age, defined by reference to five sets of aerial photographs of Goss Moor taken over the last six decades. The average number of poor-fen species per unit area in the understorey generally decreased with age. This relationship was related to the increase in canopy cover and, therefore, shade. Willow was found to invade areas with the greatest amounts of accumulated organic material and a low water table. In the oldest and driest willow, oak saplings were found, indicating the beginning of secondary woodland. An architectural analysis of willow showed that useful age descriptors were the height of the first fork, the number of live secondary shoots, tree height and dbh, all of which generally increased with age. Spatial successional patterns were characterised using the lattice-wombling technique in three large rectangles or 'tranomes'. Plant communities were associated with either abrupt or diffuse boundary types. Abrupt boundaries or ecotones were found between heath communities and densely vegetated tall-herb fen and species-poor willow carr wetland vegetation. Diffuse or ecocline transitions occurred between communities with subtle differences in their composition. Spatial relationships between swamp and poor-fen communities were taken as evidence for space-for- time successions, these patterns varied according to location and microtopography. Investigations into the water regime showed water depth was governed by substrate heterogeneity. Homogeneous microtopography was associated with deep inundations and greatest amplitude in water depth, and most closely resembled rainfall fluctuations. The most complex microtopography resulted from the most intense tin-streaming activity. Therefore the anthropogenic history of Goss Moor plays an important role in governing the contemporary water regime and vegetation distribution. Of the wetland communities, rush pasture was the driest and poor-fen the wettest. The communities of open habitats were wetter than the willow communities. The youngest willow community was drier in the summer than the other five vegetation types studied, which was indicative of the conditions necessary for willow scrub colonisation to take place. The N:P ratio revealed that nitrogen was the limiting nutrient in all of the wetland vegetation types suggesting an early stage of successional development. High water levels were thought to be responsible for the prevalence of N-limitation on Goss Moor, creating deoxygenated substrates and leading to the demise of nitrifying bacteria and thus a reduction in the rate of soil N mineralisation. Plant strategies were used to classify the species from a number of wetland communities ranging from open-water pools to willow carr, in order to apply them to Grime's triangular model. The ten communities were ordered into a logical successional sequence. However, the model needs to be modified to account for succession in the aquatic environment. Based on the findings of this thesis, a number of suggestions were made for the effective management of the wetland habitats on Goss Moor. These include: evaluation of willow scrub before removal so those areas of vegetation subsequently opened-up can be monitored; and the creation of new ponds to encourage the growth of certain poor-fen communities, which are species-rich, but only account for a small area of the whole resource.