During the 1950's and 1960's a railroad yard located in Oneida, Tennessee, was used as a creosote treatment facility for railroad ties. After the cross-ties were treated with creosote, the excess creosote was stored in an holding pond located about 100 feet north of Pine Creek (Fetterolf 1998). In 1990, during a creek modification project, creosote was discovered seeping through the banks of Pine Creek. The creosote had leached through the bottom of the pond and migrated towards the creek. In 1997, the Tennessee Department of Environment and Conservation authorized a remedial strategy prepared by Geraghty & Miller, Inc (Fetterolf 1998). The strategy involved the use of phytoremediation and a previously installed interception trench system. The primary goals of the phytoremediation plan are to stimulate biodegradation and to decrease groundwater flow, thus minimizing the migration of the contaminant into Pine Creek. Poplar trees were selected for the phytoremediation plan and were planted in two sections. The objectives of this report involved analyzing the hydrogeology of the Oneida, Tennessee site and organizing the collected data for the purpose of evaluating the impact of the phytoremediation and interception trench systems on the aquifer. The water level data was used to evaluate water level and hydraulic gradient changes due to evapotranspiration, rainfall, and groundwater extraction. It was obvious from the water level and rainfall comparison plots that the rainfall has a measurable effect on the water table elevation (i.e. groundwater flow). Some areas may be less affected because the coal layer has a tendency to decrease recharge. Meanwhile, the interception trench lowers the water level around the trench. The decrease in head occurs before and after the trench, thus the water level forms a "v-shape" at the trench. This "v-shape" lends to the notion that the hydraulic gradient also slopes towards the trench in both directions. As for the phytoremediation, there was not sufficient evidence to suggest that the water levels were being lowered by evapotranspiration. This was expected since the poplar trees were had only completed their second growing season. GMS MODFLOW was used to predict the effects on the water table due to the phytoremediation and the interception trench systems. The calibrated model did an adequate job in simulating the site when the interception trench was not in operation and the trees were not in their growing season. By using variable recharge in some areas, the results are expected to improve. For example, it is important to know the location of the coal layer so this area can be given a lower recharge value than the other areas in the model. As for the trench model, the simulated heads were much lower than the observed heads, which emphasizes that using wells is not the best method to simulate the interception trench. In the future, a transient model should be used to simulate the site with the trench operation, and the drain package could be used to model the trench itself. Meanwhile, the ET model was a valuable simulation, because it illustrates how effective the poplar trees can be even under conservative conditions. With an assumed root zone of just 3 feet and a maximum potential evapotranspiration rate of 4.6 gallons per day per tree, the majority of the site will experience the dry conditions expected. / Master of Science

This thesis focuses on reimagining what Beckholmen could be in the future, once reactivated throught architecture in both a natural and social sense. It addresses the damaging shipyard activites that have taken place over time and the public disinterest in this neglected central spot of Stockholm.

No description available.

For me, architecture is a service--a way of helping people and the environment--and I wanted my thesis to reflect this idea. This thesis combines human rehabilitation and environmental remediation in order to study how these two types of healing interact. Specifically, the program of the building is a rehabilitation center for Obsessive-Compulsive Disorder (OCD) patients (who stereotypically have an obsession with order and cleanliness). Both the patients and the site are going through the process of healing, but they are doing so in ways that juxtapose each other: while the dirt, plants, and water on the site are made cleaner, the patients are undergoing therapy that helps them understand that it is okay to be "dirtier." This brings into question what the terms "clean" and "dirty" really mean. Through my year-long research into OCD rehabilitation, environmental remediation, and the meaning of dirt, I came across a quotation that summed up this idea within my thesis. It came from the appropriately titled book, Dirt: "A landscape architect's understanding of dirt--as a fertile medium--overturns the term's negative connotations to understand it as explicitly productive." (Born 8) Therefore, my thesis explores dirt's productivity and challenges visitors' and patients' preconceptions of order and disorder. Overall, however, my goal was to create a project that allowed a forgotten, polluted site to be reclaimed by the city and for the patients, through therapy, to reclaim their lives. / Master of Architecture

In 1990, creosote contamination was discovered at a railroad tie yard in Oneida, Tennessee. A phytoremediation system that included over 1,200 hybrid poplar trees was installed between 1997 and 1998 for hydraulic control of the groundwater and enhancement of the natural biodegradation processes in the subsurface. Since then, Virginia Polytechnic Institute and State University has monitored eight polycyclic aromatic hydrocarbons (PAHs) in the soil and groundwater. They have found that concentrations of smaller and more volatile PAHs have decreased over the years as the DNAPL contamination has become more enriched with the larger PAHs. This thesis focuses on the movement of naphthalene through the subsurface because it comprises the majority of the creosote and evidence for its remediation exists. Of the many mechanisms within the phytoremediation system that serve to remediate contaminated groundwater and soil, the most important are rhizosphere bioremediation and plant uptake. However, another mechanism, direct volatilization through the soil, was thought to have significant remediation capabilities at this site. Because naphthalene is a highly volatile PAH, it was hypothesized that naphthalene is volatilizing directly through the soil to the atmosphere and that the rate of volatilization may be enhanced by the presence of the phytoremediation system. The goals of this research are to measure the amount of naphthalene that volatilizes from the subsurface and determine the factors that significantly influence this direct volatilization. A flux chamber was designed and constructed to measure naphthalene fluxes from the soil. Factors that influence direct volatilization include the groundwater level, soil moisture, precipitation, pressure changes, temperature and humidity, the most important of which we found to be the groundwater level through its influence on naphthalene concentrations in the groundwater. We found that the presence of the trees significantly affects groundwater levels. As trees transpire and lower the groundwater table, concentrations in the uppermost portion of the groundwater increase, and under dry conditions, naphthalene fluxes from the soil are maximized. To complement the field measurements of direct volatilization, we also investigated rates of volatilization and biodegradation in the laboratory. Column experiments were conducted to determine the importance of direct volatilization on biodegradation in the vadose zone. We hypothesize that the combined mechanisms of contaminant transfer to the vadose zone, followed by rapid biodegradation, speeds up remediation in contrast to biodegradation that occurs only in the saturated zone under high groundwater conditions. Several columns using contaminated and uncontaminated soil from the site were constructed with a naphthalene source. Vertical naphthalene vapor concentration profiles were measured, and first-order biodegradation rates were determined. We found that biodegradation rates in the bacterially active columns were small initially, but that the biodegradation rates of the contaminated soil dramatically increased at day 60, while the biodegradation rates of the uncontaminated soil did not begin to increase until day 150. By the end of the experiment, both soil types had approximately the same biodegradation rate, signifying that soil that had previously been exposed to naphthalene degrades naphthalene more efficiently in the early stages than soil that has not been exposed, but that over time the non-exposed soil degrades naphthalene as efficiently as the pre-exposed soil. We determined that the combined mechanisms of diffusion and biodegradation in the unsaturated zone have significant remediation capabilities. Because long-term exposure risks are associated with inhaling indoor contaminant vapors, the Johnson and Ettinger vapor intrusion model was applied to the creosote-contaminated site, as outlined in Appendix C. This model takes into account soil, chemical, and building foundation characteristics to determine a dimensionless attenuation ratio, which is the ratio of contaminant vapor concentration in an enclosed space (i.e. basement) to the vapor concentration directly above the source. For a conservative case, the Johnson and Ettinger model without biodegradation was used. We found that if the land were developed, naphthalene vapor intrusion would not pose any health risks based on regulatory standards and levels at which health effects have been recorded. / Master of Science

A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science. Johannesburg, South Africa, 2015. / Unable to load abstract

CONTEXTE GENERAL: En raison des activités anthropiques, les sols sont souvent contaminés par des métaux lourds et des hydrocarbures pétroliers. Le nombre important de sites multi-contaminés dans l'environnement met en lumière la nécessité de trouver des solutions adéquates à ces scénarios complexes d'assainissement, qui, de plus, sont rarement étudiés. Parmi les techniques d'assainissement biologique, la phytoremédiation est une technique qui se base sur les propriétés naturelles des plantes pour assainir les sols. L'utilisation conjointe des plantes et des microorganismes pour dépolluer les sols multi-contaminés est une stratégie de traitement en plein essor. Cependant, l'obstacle majeur qui entrave la réussite de tels traitements est la faible biodisponibilité des polluants dans le sol. Par conséquent, la phytoremédiation peut être assistée par des traitements chimiques et/ou biologiques afin de surmonter cette limitation et d'améliorer l'efficacité de l'assainissement. Dans cette étude, l'approche chimique implique l'ajout d'amendements biodégradables. Enfin, la stratégie biologique retenue dans ce travail est la bioaugmentation qui consiste à ajouter dans le sol des bactéries capables d'améliorer l'assainissement des polluants et/ou favoriser la croissance des plantes. PRINCIPAUX OBJECTIFS: a) Étudier le potentiel de la luzerne pour la phytoremédiation des sols multi-contaminés, b) Étudier les effets de l'acide organique de faible poids moléculaire acide citrique et le tensioactif Tween® 80 sur le processus de phytoremédiation et c) Étudier l'effet de la bioaugmentation avec la bactérie Pseudomonas aeruginosa sur le processus de phytoremédiation. METHODES: Détermination des taux de germination et de mortalité, évaluation des paramètres physiologiques des plantes. Quantification de la biomasse végétale, des métaux lourds dans les plantes, hydrocarbures pétroliers totaux (HCT) dans le sol, et indicateurs microbiologiques du sol. Calcul des paramètres de phytoremediation.RESULTATS REMARQUABLES: La luzerne a présenté une faible tolérance aux HCT du sol à 8400 mg kg-1 de matière sèche (MS). Celle-ci qui a été améliorée lorsque les HCT étaient présents à plus faible concentration (3600 mg kg-1 MS). La luzerne a été en mesure de prendre les métaux dans une proportion limitée (<100 mg kg-1 MS), tandis qu'elle a eu un effet positif sur le nombre de microorganismes du sol capables de dégrader les alcanes et sur l'activité de la lipase dans la rhizosphère. En outre, l'application combinée de l'acide citrique et du Tween® 80 a donné lieu à une amélioration plus importante de nombre et de l'activité microbienne dans la rhizosphère. La bioaugmentation avec P. aeruginosa a eu un effet sur l'amélioration de la biomasse de luzerne (augmentation de la biomasse végétale sèche totale de 71%). En outre, les taux les plus élevés d'élimination des HCT (68%, après 90 jours d'expérience) ont été obtenues dans les sols plantés avec la luzerne et bioaugmentées par P. aeruginosa. CONCLUSION GENERALE: La luzerne pourrait tolérer le sol co-contaminé par des métaux lourds et des hydrocarbures pétroliers, ce qui est une caractéristique essentielle en phytoremédiation. La luzerne ne peut cependant pas être considérée comme une espèce capable d'extraire activement les métaux lourds, même en présence d'amendements chimiques ou par bioaugmentation. Néanmoins, l'augmentation du nombre et de l'activité microbienne dans la rhizosphère a confirmé le potentiel de cette plante à être utilisée avec succès dans le traitement des hydrocarbures pétroliers. Ces effets ont été par ailleurs renforcés par l'application conjointe d'acide citrique et de Tween® 80. Enfin, la combinaison de la phytoremédiation et de la bioaugmentation semble une approche prometteuse pour réaliser l'assainissement des hydrocarbures pétroliers, lorsqu'ils sont présents dans des sols multi-contaminés / GENERAL BACKGROUND : As a result of anthropogenic activities, soil resources remain contaminated with heavy metals and petroleum hydrocarbons. The high frequency of occurrence of multi-contaminated soils in the environment brings to light the necessity to find remediation solutions adequate in such complex scenarios, which besides have seldom been studied. Phytoremediation is a biologically based remediation technology, which takes advantage of the intrinsic physiological abilities of plants to remediate contaminated media. Plants and their associated microorganisms perform phytoremediation processes (e.g. phytoextraction and rhizodegradation), which can bring about the clean-up of multi-contaminated soils. However, a major constraint which hinders the success of phytotechnologies is low bioavailability of pollutants in soil. As a result, chemically- and biologically-assisted phytoremediation are possible strategies used to overcome this limitation and improve the remediation efficiency. The chemical approach presented in this study involves the addition of biodegradable soil amendments to increase the ability of contaminants to be transferred from a soil compartment to plants and microorganisms. The biological strategy explored herein consists of inoculating contaminated soils with bacteria (bioaugmentation) able to improve remediation of pollutants and/or promote plant features.MAIN OBJECTIVES: a) To investigate the phytoremediation potential of alfalfa (Medicago sativa) in multi-contaminated soils b) To study the effects of the low molecular weight organic acid citric acid and the surfactant Tween® 80 on the phytoremediation process c) To assist phytoremediation with a bioaugmentation approach using Pseudomonas aeruginosa bacteria. METHODOLOGIES: Determination of germination and mortality rates, assessment of plant physiological parameters. Quantification of plant biomass, heavy metals in plants, total petroleum hydrocarbons (TPH) in soil, soil microbiological indicators. Calculation of phytoremediation parameters. REMARKABLE RESULTS : Alfalfa presented low tolerance to TPH contaminated soil at 8400 mg kg-1 soil, which was improved when TPH were present at lower concentration (3600 mg kg-1 soil). Alfalfa was able to take up metals to a limited extent (<100 mg kg-1 dry matter), while had a positive effect in promoting microbial number of alkane degraders and lipase activity in the rhizosphere. Moreover, the combined application of citric acid and Tween® 80 resulted in a greater improvement of these parameters. Bioaugmentation with P. aeruginosa had a promoting effect on alfalfa biomass (71% increase of plant total dry biomass). In addition, the highest TPH removal rates (68%, after 90 days of experiment) were obtained in soils vegetated with alfalfa and bioaugmented with P. aeruginosa.OVERALL CONCLUSION: Alfalfa could tolerate a heavy metal and petroleum hydrocarbon co-contaminated soil (subject to TPH levels), which is an essential characteristic for any plant species to be used in phytoremediation. Alfalfa could not be considered as an actively heavy metal removal species as it was not able to phytoextract significant amounts of heavy metals (still in the presence of soil amendments or bioaugmentation). Nevertheless, the enhancement of microbial number and activity in the rhizosphere encouraged the potential of this plant species to be successfully used in the remediation of petroleum hydrocarbons. These effects were additionally enhanced by the joint application of soil amendments. Finally, the combination of phytoremediation and bioaugmentation seems a promising approach to achieve the remediation of petroleum hydrocarbons, when present in multi-contaminated soils

Thesis (M. Tech.: Biotechnology)-Dept. of Biotechnology and Food Technology, Durban University of Technology, 2008. xiv, 103 leaves : ill. / Phytoremediation is an emerging technology where specially selected and engineered metal-accumulating plants are used for bioremediation. Amaranthus dubius (marog or wild spinach) is a popular nutritious leafy vegetable crop which is widespread especially in the continents of Africa, Asia and South America. Their rapid growth and great biomass makes them some of the highest yielding leafy crops which may be beneficial for phytoremediation. This study was undertaken to evaluate the potential of A. dubius for the phytoremediation of Chromium (Cr), Mercury (Hg), Arsenic (As), Lead (Pb), Copper (Cu) and Nickel (Ni). Locally gathered soil and plants of A. dubius were investigated for the metals from a regularly cultivated area, a landfill site and a sewage site. Metals were extracted from the samples using microwave-digestion and analyzed using Inductively Coupled Plasma – Mass Spectroscopy (ICP-MS). Further experiments were conducted with plants from locally collected seeds of A. dubius, in a tunnel house under controlled conditions. The mode of phytoremediation, the effect of the metals on the plants, the ability of the plant to extract metals from soil (Bioconcentration Factor - BCF), and the ability of the plants to move the metals to the aerial parts of the plants (Translocation Factor - TF) were evaluated for the different metals. Finally, A. dubius was micro-propagated in a tissue culture system with and without exposure to the metal, and the effect was studied by electron microscopy.

The use of natural remediation methods to remove contaminants from waste water is becoming more popular. Plants have been used for several decades, yet their use for municipal waste water contaminated by heavy metals is limited to a few studies which focus on the Mercury and Chromium (Bennicelli, et.al, 2004). This study specifically attempted to determine the viability for using Lemna minor to remediate municipally generated wastewater contaminated with copper. The study used 100 ml samples of wastewater, artificially spiked with 8 mg/L of copper sulfate and seeded with approximately 100 Lemna minor fronds. Each treatment was repeated 15 times and distilled water was added daily to maintain 100 ml samples. The addition of Lemna minor statistically lowered the copper concentration of the treatment groups (55% reduction in total Cu concentration). No significant decrease was seen in the control groups. While Lemna minor has metals accumulation potential, its wide spread use is limited by the toxic effect of copper on Lemna minor at relatively low levels.

Ces travaux contribuent à caractériser des compartiments environnementaux (i.e. eau, sol et solution du sol, substrat, macrophytes à l’échelle individuelle et des communautés) et leur fonctionnement pour in fine améliorer l’efficacité de zones humides construites (CW) à décontaminer une masse d’eau contaminée en cuivre. Les connaissances sur le maintien de l’homéostasie de Cu chez les végétaux ainsi que sa phytotoxicité aux expositions élevées sont résumées. Les principaux mécanismes physico-chimiques et biologiques intervenant en phytoremédiation d’eaux contaminées en Cu en CW sont également discutés. Plusieurs solutions de phytoremédiation de type phytostabilisation aidée ont été évaluées en lysimètres in situ sur un site de traitement du bois contaminé au Cu, afin d’établir le potentiel de certains amendements à sorber Cu dans le substrat des CW. Les concentrations en éléments traces potentiellement toxiques (PTTE, dont Cu) et macroéléments des lixiviats migrants vers les horizons aquifères ont été quantifiées. Un laitier sidérurgique de type Linz-Donawitz enrichi en P (LDS, 1%) a permis le meilleur développement de Lemna minor L., utilisé ici comme bioindicateur, exposée aux lixiviats. En parallèle, les communautés de macrophytes ont été suivies le long du parcours de la Jalle d’Eysines, une rivière urbaine contaminée en Cu et autres PTTE. Les concentrations en PTTE ont été déterminées dans le sol, l’eau, l’eau interstitielle et les feuilles de 7 espèces de macrophytes. Un modèle statistique multivarié (analyse discriminante linéaire, LDA) a ensuite été élaboré sur la base des concentrations foliaires en PTTE pour biosurveiller l’exposition des macrophytes. Des populations de macrophytes ont aussi été prélevées sur des zones humides de contamination croissante en Cu en Europe (France, Espagne, Portugal et Italie), Biélorussie et Australie. La production de racines chez les macrophytes exposées pendant 3 semaines à des concentrations croissantes en Cu (0,08 ; 2,5 ; 5 ; 15 et 25 µM Cu) montre une variabilité intra-spécifique de la tolérance au Cu pour des populations de Juncus effusus, Schoenoplectus lacustris et Phalaris arundinacea. A l’inverse, une réponse similaire à une tolérance constitutive a été obtenue chez Typha latifolia et Iris pseudacorus, deux espèces à forte production de rhizomes. L’importance des rhizomes est discutée. Phragmites australis produit également des rhizomes, mais a présenté une variabilité intra-spécifique dans sa production racinaire en réponse à une exposition au Cu. En CW, à l’échelle du mésocosme (110 dm3), jusqu’à 99% du Cu de la masse d’eau (concentration initiale: 2.5µM Cu) ont été éliminés dans les trois modalités plantées de Juncus articulatus, P. arundinacea et P. australis, ainsi que dans le contrôle non planté. Les rôles du biofilm microbien, du substrat et des macrophytes en CW ainsi que leurs interactions sont discutés. La sélection d’écotypes de macrophytes tolérants aux PTTE pour leur utilisation en zone humide construite ainsi que les mécanismes moléculaires impliqués dans la variabilité intra-spécifique de cette tolérance, notamment chez P. australis, sont deux thèmes de recherche à promouvoir. / This work aims at characterizing environmental compartments (i.e. water, soil and soil pore water, substrate, macrophytes at the individual and community scale) and their functioning to in fine improve the effectiveness of constructed wetlands (CW) for cleaning Cu-contaminated waters. Knowledge on the homeostasis of Cu in plants and its phytotoxicity at medium and high exposures are summarized. The main physico-chemical and biological mechanisms involved in the phytoremediation of Cu-contaminated water in CW are discussed. Several aided-phytostabilisation options were in situ evaluated in lysimeters at a Cu-contaminated wood preservation site to assess the potential of four amendments to sorb Cu in a CW substrate. Concentrations of potentially toxic trace elements (PTTE, including Cu) and macronutrients of leachates migrating from the root zone to the aquifers were quantified. Based on the responses of Lemna minor L. used as a bioindicator, exposed to the leachates,.Linz-Donawitz slag spiked with P (LDS, 1%) best performed to sorb labile Cu in the root zone. In parallel, macrophyte communities were monitored along the Jalle Eysines River, an urban river slightly contaminated by Cu and other PTTE. The PTTE concentrations were determined in the soil, water, soil pore water, and in the leaves of seven macrophyte species. A multivariate statistical model was developed based on the foliar PTTE concentrations for biomonitoring macrophyte exposures. Populations of macrophytes were also collected in wetlands displaying an increasing Cu contamination in Europe (France, Spain, Portugal, and Italy), Belarus and Australia. Root production of macrophytes exposed for 3 weeks at increasing Cu concentrations (0.08, 2.5, 5, 15 and 25 µM Cu) shows an intra-specific variability of Cu tolerance in populations of Juncus effusus, Schoenoplectus lacustris and Phalaris arundinacea. In contrast, a similar response to constitutive tolerance occurred for Typha latifolia and Iris pseudacorus, two species with high production of rhizomes. The rhizome influence is discussed. Phragmites australis also produces rhizomes but showed intra-specific variability in response to Cu exposure. In a CW at mesocosm scale (110 dm3), up to 99% of Cu in water (initial concentration: 2.5μM Cu) was removed after 2 weeks in the three modalities planted with Juncus articulatus, P. arundinacea and P. australis, and in the unplanted control. The influences of microbial biofilms, the substrate, and the macrophyte species and their interactions in CW are discussed. The selection of PTTE-tolerant macrophytes for their used in CW and the understanding of molecular mechanisms underlying the intra-specific variability in PTTE- tolerance, i.e for P. australis, require further investigations.