A concentração demográfica e de sistemas coletivos de esgotamento sanitário dentro do perímetro urbano da maioria dos municípios brasileiros, dificulta a viabilização do fornecimento de serviços de tratamento de esgotos domésticos à habitações e núcleos habitacionais isolados situados em áreas periurbanas e rurais, intensificando os danos provocados pela poluição de origem antrópica ao meio ambiente e à preservação da saúde pública. Para contribuir no equacionamento deste problema, o presente estudo teve por finalidade avaliar uma wetland construída híbrida em escala real, composta por uma unidade com fluxo contínuo subsuperficial vertical seguida por uma unidade de fluxo contínuo subsuperficial horizontal, cultivadas com capim Vetiver, para o tratamento de efluente proveniente de tanque séptico. A presente configuração experimental busca uma solução de baixo custo e simplificada para o tratamento descentralizado de esgotos domésticos. A estação experimental de tratamento de esgotos, parte integrante e um dos produtos da Rede Nacional de Tratamento de Esgotos Descentralizados RENTED, foi construída no Centro Tecnológico de Hidráulica CTH / Escola Politécnica EPUSP, campus Butantã da USP, em São Paulo. O esgoto bruto foi proveniente do Conjunto Residencial da USP e do restaurante central da Cidade Universitária. As vazões média e máxima de esgoto bruto, respectivamente, de 640L.d-1 e 1600L.d-1, foram aplicadas à entrada do TS de 5.000L e deste escoaram por gravidade à entrada da wetland construída híbrida, com TDH total de 2,8d e 1,1d, respectivamente, sob aplicação das vazões média e máxima de projeto. O monitoramento do experimento em campo, incluindo o período inicial de partida, durou 6 meses consecutivos. Foram avaliados os parâmetros físico-químicos e microbiológicos do esgoto bruto e do efluente do tanque séptico e das câmaras da wetland construída híbrida durante 97 dias consecutivos. Os resultados indicaram que tanto as mudas jovens quanto as adultas de capim Vetiver adaptaram-se bem às condições ambientais. As eficiências médias de remoção no efluente tratado final quanto à matéria orgânica carbonácea foram de 96 por cento para DBO5,20 e 90 por cento para DQO, 40 por cento para N-total, 23 por cento para N-amoniacal total, 60 por cento para P-total, 52 por cento para P-PO4, 74 por cento para SST, 96 por cento para SSV, 75 por cento para sólidos sedimentáveis, 44 por cento para SDV, 88 por cento para sulfeto total, e 97 por cento para óleos e graxas totais, variando entre 73 por cento a 100 por cento . Cerca de 80 por cento da fração orgânica da matéria nitrogenada presente no esgoto bruto foi removida. A remoção de coliformes termotolerantes foi, em média, de 2 e 3 unidades log, e de Escherichia Coli, média de 1 e 3 unidades log, respectivamente, sob aplicação das vazões máxima e média, Giardia sp, média de 99,995 por cento , Cryptosporidium sp, média de 98,7 por cento , Enterovírus, média de 99,6 por cento , e Ascaris sp, média de 0,10 ovo/L. A remoção de sulfetos propiciou a geração de efluente tratado sem odores desagradáveis. A diminuição da vazão aplicada e a elevação do TDH influenciaram positivamente no desempenho do sistema com relação às remoções dos parâmetros físico-químicos e microbiológicos. Com base no presente estudo, ficou evidente o benefício da associação de wetlands construídas com fluxo vertical e horizontal no tratamento de efluente de tanque séptico. O capim Vetiver apresentou bom potencial de utilização em wetlands 8 construídas para tratamento de esgotos domésticos. O sistema experimental de tratamento apresentou flexibilidade operacional, mantendo bom desempenho inclusive nos períodos de sobrecarga. A qualidade do efluente tratado final obtido no presente estudo atende às exigências de lançamento e aos padrões de emissão de efluentes líquidos em corpos dágua e em sistemas públicos de esgotamento sanitário definidos na legislação ambiental federal e do Estado de São Paulo. A tecnologia de wetlands construídas híbridas associada ao tratamento de efluentes de tanque séptico apresentou bom potencial para o tratamento descentralizado de esgotos domésticos, inclusive em regiões com pouca disponibilidade de área livre. / The demographic concentration and collective systems of sanitation inside the urban perimeter of most Brazilian municipalities, hampers the feasibility of providing sewage treatment services to domestic dwellings and housing isolated nuclei located in peri-urban and rural areas, intensifying the damage caused by pollution of human origin to the environment and to the preservation of public health. For help in solving this problem, the present study had the purpose to evaluate a hybrid constructed wetland full-scale, composed of a unit with continuous vertical subsurface flow followed by a continuous horizontal subsurface flow unit, grown with Vetiver grass, for the treatment of effluent from septic tank. This experimental search setting a low-cost and simplified solution for decentralized treatment of household sewage. The experimental sewage treatment station, integral and one of the products of the Rede Nacional de Tratamento de Esgotos Descentralizados RENTED, was built on the Centro Tecnológico de Hidráulica CTH / Escola Politécnica EPUSP, campus Butantã of USP, in São Paulo. The raw sewage was coming from the residential condominium of the USP and the central restaurant of the University City. The average and maximum flows of raw sewage, respectively, of 640L.d-1 and 1600L.d-1, have been applied to the septic tank input to 5,000L and drained by gravity from the edge of the hybrid constructed wetland with TDH total of 2.8d and 1.1d, respectively, under application of the average and maximum flow rates. Monitoring the experiment in the field, including the early period, lasted 6 months. They were evaluated the physico-chemical and microbiological parameters of raw sewage and effluent from septic tank and the chambers of hybrid constructed wetland during 97 consecutive days. The results indicated that both the young seedlings as the adults of Vetiver grass have adapted well to environmental conditions. The average removal efficiencies in the final treated effluent as to carbonaceous organic matter were 96 per cent for BOD5,20 and 90 per cent for COD, 40 per cent for Ntotal, 23 per cent for N-ammoniacal, 60 per cent for P-total, 52 per cent for P-PO4, 74 per cent for SST, 96 per cent for SSV, 75 per cent for settleable solids, 44 per cent for SDV, 88 per cent for total sulfide, and 97 per cent for oils and greases totals, ranging from 73 per cent to 100 per cent . About 80 per cent of the organic fraction of nitrogen matter present in the raw sewage has been removed. The thermotolerants coliforms removal was, in average, of 2 and 3 log units, and Escherichia Coli, average of 1 and 3 log units, respectively, under application of the maximum and average flow rates, Giardia sp, average of 99.995 per cent , Cryptosporidium sp, average of 98.7 per cent , Enterovirus, average of 99.6 per cent , and Ascaris sp, average of 0.10 eggs/L. Removal of sulfides allowed the generation of treated effluent without unpleasant odors. The decrease in flow rate applied and the elevation of TDH influenced positively on system performance with respect to removals of chemical-physical and microbiological parameters. Based on this study, it became apparent the association benefit constructed wetlands with vertical and horizontal flow in the treatment of wastewater of septic tank. The Vetiver grass has good potential for use in constructed wetlands for wastewater treatment. The experimental system of treatment presented operational flexibility while maintaining good performance even in periods of overload. The quality of the final treated effluent obtained in this study 10 meets the requirements and emission standards of liquid effluents in water bodies and in public sanitation systems defined in federal environmental legislation and the State of São Paulo in Brazil. Hybrid constructed wetlands technology associated with the septic tank effluent treatment showed good potential for decentralized domestic wastewater treatment, including in regions with low availability of free area.

The quantity of stormwater runoff from the city of Adelaide almost matches the demand for drinking water. It therefore becomes increasingly important as an alternative source for water supply. This research focused at the Parafield Stormwater Harvesting Facility near Adelaide in order to better understand: (1) nutrient dynamics between the water column, sediments and plant community, (2) allochthonous and autochthonous sources of nutrients and (3) nutrient retention capacity of the reed bed. A weekly monitoring programme for the physical and chemical parameters of the water column, sediment and plant community was carried out over three years for specific locations within the reed bed. Ordination and clustering of the time series data revealed distinctive seasonal and spatial nutrient patterns. The concentrations for total nitrogen (TN) showed high concentrations for the summer period (1.04 to 1.86 mg/L) and low concentration for the winter season (0.25 to 0.46 mg/L). For the other nitrogen fractions in form of nitrate (NO₃⁻) and ammonium (NH₄⁺) the seasonal patterns were different to that of TN. In NO₃⁻ the concentrations were high during the summer and winter seasons and NH₄⁺ showed high concentration during the spring. The seasonality for total phosphorus (TP) showed high concentration for the spring period (0.049 to 0.163 mg/L) and low concentration for the other seasons (0.01 to 0.019 mg/L). A similar pattern has been observed for phosphate (PO₄³ ⁻) as well. The dissolved organic carbon (DOC) concentrations showed high concentrations during the summer period (21.36 to 31.64 mg/L) and low concentration during the winter seasons (5.48 to 7.14 mg/L). The seasonal pattern for the nutrient contents of the plant community showed highest concentrations during summer (5.5 to 34.2 gTN/kg) and lowest concentrations in winter (0.2 to 7.7 gTN/kg). Nutrient concentrations in the sediments were highest during the non-growing seasons (autumn and winter). This result indicated that the function of sediments changes seasonally from being a sink during the non-growing season by accumulating both allochthonous and autochthonous nutrients in the rainy season, and becoming a source during the growing seasons due to nutrient release from anaerobic sediments supporting the growth of the macrophyte community. Overall the function of sediment in reed bed pond of the Stormwater Harvesting Facility was to be a source of nutrients and therefore no accumulation of nutrients occurred during the study period. The research has demonstrated that the reed bed currently performs as a reasonable nutrient retention system with following nutrient removal rates: 0.85 mg TN /m²/day, 0.79 mg NO₃⁻ /m²/day, 0.28 mg NH₄⁺/m²/day, 0.05 mg TP /m²/day, 0.04 mg PO₄³ ⁻ /m²/day, and 5.75 mg DOC /m²/day. Seasonal difference in the water retention time showed that the for most of the nutrients the removal performance was most effective during autumn and winter with the exception of the removal performance of P forms, which most effective during spring and summer. For TN, NO₃⁻ and DOC the RE was most efficient at a residence time > 15days, for TP and PO₄³ ⁻ it is 5-10 days and for NH₄⁺ it is <;5days. Time–series modelling of the monitoring data resulted in rule-based prediction models for the different nutrients. Sensitivity analyses of the models revealed key driving variables for the nutrient dynamics of the reed bed. The prediction results revealed that the DO was the key driving variable influencing the nutrient concentrations in the water column and therefore to improve the water quality of the treatment water DO levels have to maintained above the threshold of 4 mg/L. Beside DO other key driving variables were turbidity, ORP and the nutrient levels from the previous site. Therefore the control of these parameters would be the start to develop a management plan for best-practice management in terms of water quality at the Parafield Stormwater Harvesting Facility. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1458926 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Science, 2010

<p>This report deals with the performance of a batch flow treatment of landfillleachate compared with a continuous flow system. The parameters in focus were total Kjeldahl nitrogen (TKN), BOD5 and COD. The pilot-scale experiment used eight barrels with a volume of 150 liters. Each barrel was constructed differently concerning its flow, its bed material grain size and its presence of plants or not. Four of the barrels worked in batch mode, thus four in continuous flow mode. The continuous flow systems were provided with water trough small tubes with regulators. Samples were collected once a week and analysis was carried out yielding results of BOD5, COD, TKN, pH and conductivity of the effluents. The same parameters were analyzed for the influent every week. The result shows that a wetland is a good way of treating the landfill leachate as the BOD5, COD and TKN decreases. Moreover the color, which contravenes with legislative demands in the region, was distinctly decreased. Yet the report failed to show a significant difference between batch loaded and continuous flow wetlands. More studies have to be carried out in order to determine or contradict whether batch mode in fact provides a better treatment.</p>

This report deals with the performance of a batch flow treatment of landfillleachate compared with a continuous flow system. The parameters in focus were total Kjeldahl nitrogen (TKN), BOD5 and COD. The pilot-scale experiment used eight barrels with a volume of 150 liters. Each barrel was constructed differently concerning its flow, its bed material grain size and its presence of plants or not. Four of the barrels worked in batch mode, thus four in continuous flow mode. The continuous flow systems were provided with water trough small tubes with regulators. Samples were collected once a week and analysis was carried out yielding results of BOD5, COD, TKN, pH and conductivity of the effluents. The same parameters were analyzed for the influent every week. The result shows that a wetland is a good way of treating the landfill leachate as the BOD5, COD and TKN decreases. Moreover the color, which contravenes with legislative demands in the region, was distinctly decreased. Yet the report failed to show a significant difference between batch loaded and continuous flow wetlands. More studies have to be carried out in order to determine or contradict whether batch mode in fact provides a better treatment.

The euthropthication of the Baltic Sea is a threat that is beginning to be taken seriously by the governments concerned. In Sweden, regulations concerning the allowed nitrogen (N) concentration in the effluent water from wastewater treatment plants are being tightened up. The Rimbo wastewater treatment plant has been imposed to reduce the annual mean concentration of total N in the effluent water to levels below 15 mg l-1. A more and more common way to reduce the nitrogen level in wastewater is to let the water pass through a wetland. This study investigates the possibility to build this kind of wetland at the outlet of the Rimbo wastewater treatment plant. A prestudy of the topography, soil characteristics and groundwater flow indicates that the land area in question is well suited for the construction of a wetland. A proposal for the design has been made by using a physically based computer model developed in the PRIMROSE project (PRocess based Integrated Management of constructed and Riverine wetlands for Optimal control of wastewater at catchment ScalE), which is financed by the EU. Analysis of the residence time distribution (RTD) is a tool for understanding wetland design characteristics and can be used for wetland engineering such as optimizing design for best possibleefficiency in nitrogen removal. In order to characterize the performance of a wetland, it is useful to translate the RTD to a key figure representing the treatment efficiency. In this work, two types of such key figures have been used. Key figure 1 gives the hydraulic efficiency and Key figure 2 gives an estimation of the nitrogen retention by an integration of hydraulic characteristics and the chemical transformation of nitrogen. The results of this study show that constructing a wetland in Rimbo probably would be an efficient way to reduce the nitrogen level at the effluent of the wastewater plant below the limits of the regulations. In addition, a wetland would form a nice place of recreation for the people in Rimbo and also make a good habitat for birds. / Övergödningen i Östersjön är ett problem som uppmärksammas alltmer. Ett led i att minska kvävebelastningen på Östersjön är ökade krav på rening i de svenska kommunala reningsverken. Rimbo avloppsreningsanläggning har blivit ålagd ett riktvärde för totalkväve på 15 mg l-1 i utgående vatten, vilket motsvarar en reningsgrad som inte uppnås idag. Ett alltmer vanligt sätt att minska föroreningshalterna är att anlägga våtmarker i anslutning till reningsverken för att efterpolera spillvattnet. Det här arbetet är en del av en förstudie till en sådan våtmark i Rimbo. En förundersökning av topografi, jordart och grundvattenflöden indikerar att det område som föreslagits i anslutning till reningsverket i Rimbo lämpar sig väl för ett våtmarksbygge. Förslag till utformning har tagits fram med hjälp av en fysikaliskt baserad modell över vattenströmning, utvecklad inom det EU-finansierade projektet PRIMROSE (PRocess based Integrated Management of constructed and Riverine wetlands for Optimal control of wastewater at catchment ScalE). Analys av vattnets uppehållstidsfördelning ger förståelse för våtmarkens egenskaper och kan därför användas vid t ex optimering av våtmarksdesign med avseende på kväverening. För att på ett enkelt sätt kunna jämföra olika våtmarkers effektivitet är det praktiskt att översätta uppehållstidsfördelningen till ett nyckeltal för reningseffekten. I det här arbetet har två olika sådana nyckeltal beräknats. Det första ger den hydrauliska effektiviteten och det andra bygger på en metod där våtmarkens interna hydraulik integreras med den kemiska omvandlingen av kväve. Nyckeltal 1 ger ett mått på hur stor del av volymen i våtmarken som används för kväverening, medan Nyckeltal 2 ger ett mått på den procentuella kväveavskiljningen. Den här förstudien visar att en våtmark sannolikt skulle vara ett utmärkt sätt att klara riktvärdet för kvävehalten vid reningsverket i Rimbo. Därutöver skulle en våtmark kunna utgöra ett positivt inslag i landskapet och öka den biologiska mångfalden, inte minst vad gäller fågelliv.

Vertical flow constructed wetlands (VF CWs) are becoming increasingly popular for onsite wastewater treatment due to their high oxygen transfer capacity and high nitrification rates. However, there are still some question marks regarding (1) how the treatment performance of VF CWs is affected by design and operational parameters, and (2) the treatment processes happening inside the wetland bed as the wastewater percolates through. In this study, we investigated the effects of filter media (coarse sand or fine gravel), dosing regime (hourly with 4 mm or bi-hourly with 8 mm) and plant presence (with or without Phragmites australis) on the  treatment performance and concentration depth profiles of pollutant removal in six pilot-scale VF CWs treating primary treated domestic wastewater. Grab samples of wastewater were collected every 2-3 weeks during 5 months and analyzed for organic matter, suspended solids, nitrogen and E. coli. We found that sand beds performed better than gravel beds for removal of all pollutants except total nitrogen, although for long term operation gravel may be less susceptible to clogging. The overall treatment performance was not affected by different dosing regimes, but the concentration depth profiles showed that smaller and more frequent doses led to more pollutant removal in the upper part of the beds. The presence of plants was moderately important for the removal of ammonium, but had no effect on other pollutants.

<p>Treatment wetlands play an important role in reducing nitrogen content in wastewater and agricultural run-off water. The main removal process is denitrification and the removal efficiency depends on the hydrological and microbiological features of the wetland, especially in terms of water residence times and denitrification rates. The aim of this thesis was to increase the understanding of the coupled hydrological and microbiological processes regulating the denitrification capacity. This was done by applying a broad spectrum of analyses methods, including tracer experiment, water flow modeling, denitrification rate measurements, and analyses of the microbial community structures. The tracer experiment and flow modeling revealed that the wetland design, especially the vegetation, largely can affect the water residence time distributions in wetlands. In the investigated wetland, vegetation dominated the water flow, explaining 60-80% of the variance in water residence times, whereas basin shape only explained about 10% of the variance, but also mixing phenomena significantly affected the residence times and could considerably delay solutes. Measured potential denitrification rates in the wetland exhibited significant spatial variations, and the variations were best described by concentration of nitrogen in sediments and water residence time. Analyses of the denitrifying bacteria populations indicated that a few key populations dominated and that the community diversity increased with decreasing nutrient levels and increasing water residence times. Moreover, it was found that denitrification rates in terms of Menten and first order kinetics can be evaluated by fitting a mathematical expression, considering denitrification and other nitrogen transforming processes to measured product formation in nitrate limited experiments.</p>

No description available.

To foster the practical development of constructed wetlands used for wastewater treatment in Turkey, a pilot-scale subsurface constructed wetland system (90 m2) was designed to treat the domestic wastewater produced by 60 PE living in the residential area of METU. In summer 2001, two parallel sets of hybrid wetland systems (vertical flow connected with horizontal flow) with identical design configuration, but with different fill media (blast furnace granulated iron slag and gravel) were built on the old sludge-drying bed of the abandoned wastewater treatment plant of METU, which has not been operating since the 1990s. Wetland cells were planted with common reed (Phragmites australis). The main objective of this research was to quantify the effect of different filter media on the removal performance of subsurface flow constructed wetlands in the prevailing climate of Ankara. Thus, slag-filled and gravel-filled vertical flow wetlands were operated identically with pre-settled domestic wastewater (3 m3.d-1) at a hydraulic loading rate of 110 mm.d-1 for 12 months, intermittently. According to the first year results, annual average removal efficiencies for the slag and gravel wetland cells were as follows: TSS (63% &amp / 59%), COD (47% &amp / 44%), NH4+-N (88% &amp / 53%), TN (44% &amp / 39%), PO43--P (44% &amp / 1%) and TP (45% &amp / 4%). The slag-filled vertical flow system removed phosphorus and ammonium efficiently than the gravel-filled system due to the differences in physical structures and chemical compositions of the fill media, and the different aerobic and anaerobic environments within the wetland cells. These results indicated that the well-designed constructed wetlands could also be used for secondary and tertiary treatment in Turkey, successfully.

I investigated if constructed wetlands provide breeding habitat for the Horned Grebe (Podiceps auritus) in northwest Alberta. Over two years, I conducted bird surveys of 201 borrow-pits (ponds created during road construction) and 18 natural wetlands and collected data on local habitat and landscape features. For subsets of ponds, I also collected water chemistry and invertebrate data, and conducted stable isotope analysis. Grebes occurred on 36% of borrow-pits and produced chicks on 61% of occupied sites in 2007 and 81% in 2008. Grebes occurred more frequently on larger ponds, with more emergent vegetation, and avoided forested ponds that supported beaver activity. Horned Grebes are generalist foragers that did not select nesting ponds based on food-web structure. Twenty-six other bird species used borrow-pits, with distinct assemblages occurring on agricultural versus forested ponds. My study indicates that wetland construction offers a viable method for creating habitat for Horned Grebes and other species. / Ecology