Constructed wetlands are largely used for water treatment both in agricultural land and for treating water from municipal and industrial waste. These wetlands need to be managed in order to work properly. How to deal with the large amount of vegetation harvested in the wetlands has withdrawn a great concern. The application of using wetland biomass as the co-substrates in anaerobic digestion was studied in this project. Plant materials, mostly Phragmites australis (common reed) from three different wetlands were used as raw material to produce biogas. The methane production using reed material harvested from municipal wastewater, industrial wastewater and an agricultural wetland are 66, 106, 144 ml/g VS respectively, which were lower than the suggested number 180ml/g VS. The gas potential remains a lot to be improved such as harvesting at summer to reduce the lignin content and changing the co-digestion mixing level to adjust to the optimal C/N ratio. Chemical analyses were performed concerning the gas yield and the residue quality. The digested residues showed a low concentration of cadmium, providing a non-toxic possibility to be spread on farm land as fertilizers, and closing the nutrient circle from land into water and back to land again. Pretreatments in the biogas process are usually focusing on the reduction of the lignocellulosic content in the raw material. Assessment of costs and benefits is needed for using wetland reed in the biogas production and applying any pretreatment methods.

Made available in DSpace on 2014-07-29T15:01:49Z (GMT). No. of bitstreams: 1 Dissertacao Lorena L M Abrantes.pdf: 4341681 bytes, checksum: 30126c561a517a7154d7108de137e004 (MD5) Previous issue date: 2009-08-28 / This study aimed to assess the efficiency of two vegetal species in the treatment of the sanitary sewer, in constructed wetlands system. Specifically, it aimed to evaluate the efficiency of the species Typha angustifolia (narrow-leaf cattail) and Phragmites australis (common reed), in their possible combinations, in the treatment of the sanitary sewer, in a constructed wetlands system, of vertical subsuperficial flux, with two flux directions (ascendant and descendant), related to the attributes: organic material, apparent color, ammonium nitrogen, phosphate, turbidity, chlorides, hardness, electrical conductivity, solids and thermotolerant coliforms. The experiment was conducted in the Researching Station in Sewer Treatment with Plants RSSTP (UFG), located in the Sewer Treatment Station (STS) Samambaia, in Goiânia, Goiás State, Brazil. The experimental unit has twenty four modules, grouped sequences of two modules (initial and final modules). Raw sewage which comes from the initial part of the ETE facultative pond was pumped into the deep of the treatment initial modules, filled up with substrate layers (in the deep filled up with rocks category number 3, followed by rocks category number 1, washed sand, and again rocks category number 1) and planted with cattail or reed. After going up by the vegetated substrate (ascendant vertical flux) the sewer was drained and conducted to the final treatment modules equally filled up and vegetated with one of the species, although being applied in the surface and drained by the deep (vertical descendant flux). The tax of sewer application was of 80 L.m-2dia-1, corresponding to a treatment area of 2 m2 per inhabitant. A year after the system implementation, during the period of 6 months, sewer samples were collected after passing through the flux sequences, each one with the combination of the two vegetal species, for the evaluation of the sewer attributes and calculation of the efficiency in the treatment. The results were analyzed by the Statistical Analysis System (SAS program), being used the tests F and the Tukey Kramer, considering 5% of probability. There were no meaningful differences in the efficiency of the treatments in the removal of the attributes: biochemical oxygen demand, chemical oxygen demand, ammonium nitrogen, phosphate, thermotolerant coliforms, chlorides, hardness, dissolved total solids and volatile total solids. The cattail was more efficient in the apparent color removal and turbidity. The reed presented more efficiency in the total solids removal. The position of the plant in the module sequence did not influence the apparent color and turbidity removals. The reed in the final module increased the removal of the attributes total solids and fixed total solids. It´s possible to verify that the technology of sewer treatment by using plants is efficient, since the species cattail and reed in the adopted system, provided results with removals higher 60% for the of the attributes: biochemical oxygen demand, chemical oxygen demand, apparent color, ammonium nitrogen, phosphate, thermotolerant coliforms and turbidity. / O presente estudo teve como objetivo avaliar a eficiência de duas espécies vegetais no tratamento do esgoto sanitário, em um sistema de alagados construídos. Especificamente, objetivou-se avaliar a eficiência das espécies Typha angustifolia (Taboa) e Phragmites australis (Caniço), em suas combinações possíveis, no tratamento de esgoto sanitário, em um sistema de alagados construídos, de fluxo subsuperficial vertical, com dois sentidos de fluxo (ascendente e descendente), concernente aos atributos: matéria orgânica, cor aparente, nitrogênio amoniacal, fosfato, turbidez, cloretos, dureza, condutividade elétrica, sólidos e coliformes termotolerantes. O experimento foi conduzido na Estação de Pesquisas em Tratamento de Esgotos com Plantas Eptep (UFG), localizada na Estação de Tratamento de Esgotos (ETE) Samambaia, em Goiânia, GO. A unidade experimental possui vinte quatro módulos, agrupados em sequências de dois módulos (módulos iniciais e finais). Esgoto sanitário bruto proveniente da parte inicial da lagoa facultativa da ETE foi bombeado no fundo de módulos iniciais de tratamento preenchidos com camadas sobrepostas de substrato (no fundo com brita número 3, na sequência brita número 1, areia lavada e novamente brita número 1) e plantados com taboa ou caniço. Após subir pelo substrato vegetado (fluxo vertical ascendente) o esgoto era drenado e conduzido aos módulos finais de tratamento, igualmente preenchidos e vegetados com uma das espécies, todavia sendo aplicado na superfície e drenado pelo fundo (fluxo vertical descendente). A taxa de aplicação de esgoto foi de 80 L.m-2dia-1, correspondendo a uma área de estação de tratamento de 2 m2 por habitante. Um ano após a implantação do sistema, por um período de seis meses, amostras do esgoto foram coletadas após passar pelas sequências de fluxo, cada uma com uma combinação das duas espécies vegetais, para avaliação dos teores de atributos do esgoto e cálculo da eficiência do tratamento. Os resultados foram analisados pelo programa Statistical Analysis System (SAS), realizando-se os testes F e de Tukey Kramer, a 5% de probabilidade. Não houve diferença significativa entre as eficiências dos tratamentos na remoção dos atributos: demanda bioquímica de oxigênio, demanda química de oxigênio, nitrogênio amoniacal, fosfatos, coliformes termotolerantes, cloretos, dureza, sólidos totais dissolvidos e sólidos totais voláteis. A taboa foi mais eficiente na remoção da cor aparente e da turbidez. Já o caniço apresentou uma eficiência maior na remoção de sólidos totais. A posição da planta na sequência de módulos não influenciou na remoção da cor aparente e da turbidez. O caniço no módulo final influenciou positivamente na remoção dos atributos sólidos totais e sólidos totais fixos. Verifica-se que a tecnologia de tratamento de esgoto por plantas é eficiente, uma vez que as espécies taboa e caniço no sistema de fluxo subsuperficial vertical ora adotado proporcionaram resultados com remoções superiores a 60% para os atributos demanda bioquímica de oxigênio, demanda química de oxigênio, cor aparente, nitrogênio amoniacal, fosfatos, coliformes termotolerantes e turbidez.

Les plantes envahissantes sont considérées comme l'une des plus grandes menaces sur les espèces, mais leurs impacts sur les amphibiens demeurent peu connus. L’objectif de ce projet est de déterminer l’effet de l’établissement du roseau commun (Phragmites australis) sur la répartition des amphibiens et sur leur développement larvaire. Il est présumé que cette plante s'accapare l'espace et les ressources disponibles en produisant une importante biomasse, qu’elle peut modifier l’hydrologie des marais et la structure des communautés d’amphibiens. J’ai évalué les facteurs influençant la répartition des amphibiens selon les caractéristiques des étangs et du paysage dans 50 sites envahis ou non à divers degrés. Des expériences ont également été menées afin d’étudier les répercussions de trois densités de roseau sur des têtards de la Grenouille des bois (Lithobates sylvaticus) et sur la qualité de son habitat. Mes résultats suggèrent que le roseau à forte densité ralentit le développement larvaire de la grenouille des bois et influence les assemblages phytoplanctoniques. Cependant, il n’y a aucune relation entre la densité de la plante et la survie, la morphologie des têtards et les caractéristiques biotiques et abiotiques de l’eau. Dans notre aire d’étude, le paysage autour des étangs a une plus grande influence sur la répartition des amphibiens que l'établissement du roseau. Toutefois, la probabilité d’assèchement est plus élevée lorsque la plante est établie en grande quantité, ce qui, si l’envahissement s’intensifie, aura un effet néfaste sur la survie des têtards et mettra en péril la persistance des populations. / Invasive plants are considered one of the greatest threats to species, but their impact on amphibians is still poorly understood. The objective of this project is to determine the effect of the establishment of common reed (Phragmites australis) on amphibian distribution and larval development. It is thought that this plant monopolizes space and resources by producing a large biomass, and may alter wetland hydrology and amphibian community structure. I evaluated the factors influencing amphibian distribution according to the characteristics of ponds and the surrounding landscape in 50 sites invaded or not by reeds to varying degrees. Experiments were also conducted to study the impacts of three reed densities on wood frog tadpoles (Lithobates sylvaticus) and the quality of their habitat. My results suggest that high reed density slows wood frog larval development and influences phytoplankton assemblages. However, there is no relationship between, plant density and survival, tadpole morphology and water biotic and abiotic characteristic. In our study area, the landscape surrounding ponds has a greater influence on amphibian distribution than does reed establishment. However, the desiccation probability is higher when the plant is established in high quantities, which, if the invasion intensifies, will have an adverse effect on tadpole survival and therefore population persistence.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Les plantes envahissantes menacent la biodiversité ainsi que les activités humaines. Afin de les maîtriser, la pulvérisation d'herbicides est une méthode fréquemment employée en Amérique du Nord. Cette approche ne fait pas toujours consensus et est même parfois interdite ou restreinte, ce qui justifie le recours à d'autres options. Les alternatives peuvent toutefois s'avérer rares, comporter d'importantes limitations ou sont peu documentées. Cette étude vise à tester l’efficacité de méthodes permettant de maîtriser et de prévenir les invasions de roseau commun (Phragmites australis), l'une des plantes envahissantes les plus problématiques sur le continent nord-américain, tout en limitant au minimum l'utilisation d'herbicides. Le potentiel de quatre méthodes de lutte aux petites populations de roseau bien établies a d'abord été évalué : l’excavation avec enfouissement sur place, le bâchage, l’excavation avec enfouissement sur place combinée au bâchage, et la fauche répétée. Les résultats ont montré que l'excavation avec enfouissement sur place, avec ou sans bâchage, a entraîné une élimination presque totale des populations visées, ce qui est comparable ou supérieur à l'effet généralement obtenu avec la pulvérisation d'herbicide. Le bâchage avec des toiles opaques, maintenues pendant un an, a pour sa part entraîné une maîtrise partielle du roseau, suggérant qu'une application prolongée serait nécessaire pour l'éradication de la plante. La fauche répétée, exécutée à raison de cinq fauches par été pendant deux ans, a fourni une efficacité mitigée. Les résultats suggèrent néanmoins que la fauche pendant plusieurs années contribue à affaiblir la plante, ce qui pourrait aider à son confinement. Une méthode additionnelle a été expérimentée afin de traiter les tiges éparses de roseau tout en limitant les risques d'effets hors cibles, soit le badigeonnage manuel d’herbicide. Suite à ces tests, les résultats ont montré une diminution importante de la densité des tiges, ce qui suggère que la méthode est efficace afin d'éliminer les repousses après un traitement initial, et pourrait également être employée sur de jeunes populations clairsemées. L'effet d'un ensemencement préventif de plantes herbacées sur l'établissement de semis de roseau a également été étudié, suite à des traitements sur de vastes parcelles de sol nu. Les résultats suggèrent que la méthode est efficace afin de limiter la propagation du roseau par semences et qu'un suivi périodique suite à l'intervention serait suffisant afin de maintenir l'effet préventif. / Invasive plants threaten biodiversity as well as human activities and in North America, attempts to control them often rely on the spraying of herbicides. This approach does not always achieve consensus and is sometimes forbidden or restricted, encouraging managers to consider other options. Alternatives can however prove to be rare, involve serious limitations or be poorly documented. This study aims at testing the efficiency of methods for the control and prevention of invasions by common reed (Phragmites australis), one of the most problematic invasive plants on the North American continent, all while reducing herbicide use to a minimum. The potential of four methods for the control of small, well established stands of common reed has first been evaluated: excavation and on-site burial, covering with heavy-duty tarps, excavation and on-site burial combined with covering with heavy-duty tarps, and repeated cutting. Results have shown that excavation with on-site burial, followed or not by covering with heavy-duty tarps, led to an almost complete elimination of the populations targeted, which is comparable or superior to the effect typically obtained with herbicide spraying. Covering common reed with opaque heavy-duty tarps, held in place for one year, lead to partial control of the plant, suggesting that holding the tarps in place for a longer period would be necessary to foresee the eradication. Cutting, repeated five times per summer for two years, gave mixed results. The results suggest, however, that cutting during multiple years contributes to weakening the plant, which could help to its confinement. An additional method, the hand-wicking of common reed stems with herbicide, has been tested to treat scattered stems while limiting off-target effects. Following these tests, the results have shown an important reduction of the density of reed stems, which suggests that the method is effective to control common reed regrowth after an initial treatment, and could be used on young stands. The effect of seeding herbaceous plants on the establishment of common reed seedlings has also been evaluated, following the sowing of vast plots of bare soil. The results suggest that the method is an efficient way of limiting the propagation of common reed through seed dispersal. Results also suggest that periodic follow-ups to eliminate seedlings would be sufficient to maintain the preventive effect.

In Australia, significant effort goes into reducing the amount of nitrogen and phosphorus entering inland waters from point sources. However, little is known of the extent to which riparian organic matter may act as a source of these nutrients. Also, whilst the relationships between the nitrogen, phosphorus and carbon cycles are broadly known, there is little quantitative data regarding the release of these elements from Australian riparian organic matter and their subsequent microbial mineralisation within aquatic environments. In particular, comparatively little is known of their comparative role in nutrient and organic matter cycling within anoxic zones, and the influence that different riparian organic matter may have on stream water quality. This lack of such data presently hampers the ability of water managers to make educated decisions regarding the management of riparian zones in Australia. In order to improve understanding in this area, a combination of laboratory and in situ experiments were carried out in order to compare the abiotic release and aerobic/ anaerobic mineralisation of leaf derived dissolved organic carbon (DOC), dissolved nitrate/nitrite (NOx) and soluble reactive phosphorus (SRP) under different environmental conditions. Four plants common to Australian riparian zones were investigated: two native species, Eucalyptus camaldulensis (gum) and Phragmites australis (common reed), and two exotic species, Salix babylonica (willow) and Lolium multiflorum (rye grass). After 30 days, formaldehyde inhibited 1g willow and rye grass extracts contained the most SRP (0.7 mg/L), whilst gum extracts contained 0.3 mg/L and common reed 0.1 mg/L of SRP.Willow and rye grass abiotically released twice as much NOx than gum and common reed, although concentrations were only between 0.05-0.1 mg/L. Gum and common reed released the most DOC per gram of leaf matter (14 and 12 mmol/g of leaf matter respectively), but based on the initial carbon content of each leaf type, the largest percentage contributor of DOC under abiotic conditions was common reed and rye grass (both 38% mass/mass), with gum (33% mass/mass) and willow (30% mass/mass) being smaller contributors. The most bioavailable DOC was released by rye grass and common reed, with between 83 and 94% of this DOC microbially mineralised after 30 days in oxic conditions. When conditions were not inhibited, microbial growth was evident almost immediately in willow, rye grass and common reed leaf extracts. However, microbial growth was suppressed for the first 48 hours in gum leaf extracts. After this suppression period, the rate of DOC mineralisation was equal in willow and gum leaf extracts (0.1 day-1). Under anoxic conditions, the rate and extent of DOC mineralisation of willow and gum leaves depended on the type of electron acceptor provided. Added nitrate and iron III enhanced the mineralisation of both willow and gum leaves relative to no terminal electron acceptors (from zero to 0.01-0.04 and 0.002- 0.004 moles/day respectively), but added sulphate only enhanced the mineralisation of gum leaves (0.04 moles/day). When no additional electron acceptors were provided, particulate leaf mineralisation was more extensive under oxic than anoxic conditions. However, the mineralisation of leaf derived DOC were the same regardless of oxygen availability, and after 35 days in either condition the percentage of leaf DOC mineralised for each leaf type was of the order common reed > rye grass > willow > gum. All the leaf types tested were able to sustain the caddis fly larvae Triplectides australis under controlled laboratory conditions, and survival rates were high using all four leaf types as a food source. Triplectides australis did not significantly increase the amount of DOC released from each type of leaf matter, but they did consistently increase the proportion of simple carbohydrates present within the DOC fraction. The results of these experiments suggest that changes to riparian vegetation, particularly from the native to exotic species used in this study, will inherently alter in-stream concentrations of dissolved carbon and nutrients (particularly SRP). This potentially will affect in-stream, hyporheic and subsurface processes, particularly in areas where surface water flow is low and riparian leaf inputs are high.

Les plantes envahissantes sont considérées comme l'une des plus grandes menaces sur les espèces, mais leurs impacts sur les amphibiens demeurent peu connus. L’objectif de ce projet est de déterminer l’effet de l’établissement du roseau commun (Phragmites australis) sur la répartition des amphibiens et sur leur développement larvaire. Il est présumé que cette plante s'accapare l'espace et les ressources disponibles en produisant une importante biomasse, qu’elle peut modifier l’hydrologie des marais et la structure des communautés d’amphibiens. J’ai évalué les facteurs influençant la répartition des amphibiens selon les caractéristiques des étangs et du paysage dans 50 sites envahis ou non à divers degrés. Des expériences ont également été menées afin d’étudier les répercussions de trois densités de roseau sur des têtards de la Grenouille des bois (Lithobates sylvaticus) et sur la qualité de son habitat. Mes résultats suggèrent que le roseau à forte densité ralentit le développement larvaire de la grenouille des bois et influence les assemblages phytoplanctoniques. Cependant, il n’y a aucune relation entre la densité de la plante et la survie, la morphologie des têtards et les caractéristiques biotiques et abiotiques de l’eau. Dans notre aire d’étude, le paysage autour des étangs a une plus grande influence sur la répartition des amphibiens que l'établissement du roseau. Toutefois, la probabilité d’assèchement est plus élevée lorsque la plante est établie en grande quantité, ce qui, si l’envahissement s’intensifie, aura un effet néfaste sur la survie des têtards et mettra en péril la persistance des populations. / Invasive plants are considered one of the greatest threats to species, but their impact on amphibians is still poorly understood. The objective of this project is to determine the effect of the establishment of common reed (Phragmites australis) on amphibian distribution and larval development. It is thought that this plant monopolizes space and resources by producing a large biomass, and may alter wetland hydrology and amphibian community structure. I evaluated the factors influencing amphibian distribution according to the characteristics of ponds and the surrounding landscape in 50 sites invaded or not by reeds to varying degrees. Experiments were also conducted to study the impacts of three reed densities on wood frog tadpoles (Lithobates sylvaticus) and the quality of their habitat. My results suggest that high reed density slows wood frog larval development and influences phytoplankton assemblages. However, there is no relationship between, plant density and survival, tadpole morphology and water biotic and abiotic characteristic. In our study area, the landscape surrounding ponds has a greater influence on amphibian distribution than does reed establishment. However, the desiccation probability is higher when the plant is established in high quantities, which, if the invasion intensifies, will have an adverse effect on tadpole survival and therefore population persistence.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

No description available.

Many plant species are closely related to river biotopes or to biotopes influenced by rivers. River systems create important linear corridors in ecosystems and directly or non-directly influence spatial spread of species in these environments. This offer many questions about species spread in this system. We can answer these questions by using molecular methods. Using 10 microsatellite (SSRs) primers, 202 individuals of Phragmites australis from 60 populations were analysed. Those analyses allowed reveal kinship of individuals, obtain information about spatial spread of populations and about spreading of common reed. Phragmites australis creates both - monoclonal and polyclonal - populations. Dependence of rate of clonality on environment was revealed. Populations from river banks are more monoclonal, populations from pond shores are more polyclonal. Populations are isolated. The highest percentage of variability was explained on among-population level. This is common for anemochoric species. Communication between populations is present, more on shorter distances. Evidence for vegetative spread was found on short distance. Generative spread is much more common. Long-distance spreading is mediated by generative diaspores - seeds. This spreading includes within-river spread, among-river spread and spreading...