Dissertations / Theses on the topic 'Soils Soil colloids'

Thesis (M.S.)--University of Kentucky, 2002.
Title from document title page. Document formatted into pages; contains xiii, 163 p. :ill. Includes abstract. Includes bibliographical references (p. 152-162).

Particulate P constitutes a significant portion of the total P found in surface runoff water. Water dispersed P-containing particles can travel long distances via surface runoff and reach water bodies causing decrease in water quality. The main objective of the study was to evaluate the potential facilitation of P transport by the water dispersed soil colloids (WDC) using three KY soils with a long-term record of poultry manure, and fertilizer P applications. Sequential fractionation for both whole soils and colloidal samples revealed that the WDC had a greater total and labile P content than the soil as a whole. Also, application of manure and fertilizer P seemed to decrease colloidal organic P fractions and increase the inorganic P fractions over the period of a growing season (May to September). Laboratory settling kinetics experiments were set up for the clay-colloidal fractions of the soils. It was shown that particulate P fractions paralleled WDC settling kinetics whereas dissolved P fractions remained in solution even after 36 hours. Field taken intact soil cores were leached with colloidal suspensions to test the effect of WDC on the vertical P movement. Results illustrated the preferential flow of particulate P though the macropores. When water was applied to the manure amended soil, dissolved P levels increased significantly over the control. WDC additions lowered dissolved P levels to the manure-amended columns, by sorbing to the WDC particles, but still greater than the dissolved P levels of the columns that had not been applied with manure.

La prévision du transport et de la rétention des colloïdes représente un enjeu environnemental majeur car ces particules peuvent entraîner des polluants adsorbés ou bien être des polluants eux-mêmes. Les modèles utilisés actuellement pour prédire le devenir des colloïdes dans les sols sont basés sur des mécanismes déduits des courbes de percée (évolution de la concentration en fonction du volume de pore ou du temps) après injection de particules dans une colonne de milieu poreux. Le but de cette thèse est de compléter cette compréhension avec des mesures internes grâce à l’Imagerie par Résonance Magnétique (IRM).L’IRM permet de mesurer la distribution 1D et/ou 2D de particules super-paramagnétiques le long d’un échantillon pendant une expérience de transport dans un milieu poreux. Le couplage de cette technique avec l'étude des courbes de percée donne une approche globale. Nous avons effectué plusieurs expériences de transport dans des colonnes de milieux poreux de complexité de porosité croissante : billes de verre, sable, agrégats de sol, et sol non perturbé.A partir des expériences de transport dans les milieux poreux modèles saturés, nous avons montré que la dispersion est moins importante que la théorie le prévoit et qu’elle est fortement dépendante des effets d’entrée dans la colonne. Cette dépendance est aussi observée pour les mécanismes d’adsorption. Les expériences dans les agrégats de sol ont montré une forte adsorption et un relargage constant, dépendants de la vitesse d’injection. Finalement, des expériences de pluie dans des colonnes de sol non perturbé insaturé ont permis de suivre l’évolution des teneurs en eau et en particules dans le temps
The ability to predict transport and retention of colloidal particles is a major environmental concern as such particles can carry adsorbed pollutants towards the groundwater or be pollutants themselves. The models currently used to predict the fate of colloids in soils are based on mechanisms inferred from breakthrough curves (evolution of concentration as a function of pore volume or time) after injection of particles into a column of porous media. In this thesis we aim to complement this comprehension with internal measurements by Magnetic Resonance Imaging (MRI).MRI provides 1D and/or 2D distribution of contrast agent particles in time along the sample axis during transport experiment through a porous medium. This technique, together with the study of breakthrough curves gives a global approach. We performed several transport experiment in columns of porous media of increasing complexity: glass beads, sand, soil aggregates, and undisturbed soil.From transport experiments in model porous media we show that dispersion is less important than expected and strongly dependent on entrance effects in the column. This dependence is also observed for adsorption. Experiments in soil aggregates showed a strong adsorption but also a constant release, dependent on the flow rate. Finally, rain experiments in undisturbed sol columns allowed following water content and particles as a function of time

Exposure of sulfidic sediments to atmospheric conditions can under various environmental and anthropogenic influences. The oxidation of sulfides results in the production of acidity, dissolution of aluminosilicates and pedogenci development. This process has acid sulfate landscapes throughout the world identified as major emitters of elevated concentrations of chemical metals. This emission of acidity and metals alters the bioaccessibility and subsequently has a deleterious impact on the surrounding biologic environment. Despite this, the examination of the biologic impact in these landscapes has received only minimal attention. Passive and dynamic hydrogel techniques were used to measure the bioaccessibility of metals in sediments and waters. The technique involved the construction of a restricted pore-size thin-film hydrogel that allowed for the diffusion of the bioaccessible fraction, composed of the free-ion and easily dissociable metal-complexes. The dynamic hydrogel technique contained a resin sink, which allowed for a time-integrated flux concentration to be calculated. The dynamic hydrogel technique was trialled and found to correlate with the pygmy mussel (Xenostrobus securis) aluminium uptake for short exposure periods (24 hours).The dynamic hydrogel metal concentration was also found to correlate to indpendantly measured pore water and simultaneously extracted metal (SEM) concentrations. The hydrogel techniqe was further applied to investigate the sediment-water interface in drained and non-drained acid suflate landscapes. The studied Australian and Finnish acid sulfate landscapes showed contrasting relationships between the acid volatile sulfides (AVS) and SEM fractions. In the Australian sediments, a conversion of AVS-S to FeS2-S occurs with depth driven by a polysulfide pathway, whilst the Finnish sediments displayed a persistence of AVS-S with depth with limited conversion to FeS2-S. Distinct variations exist at the sediment-water interface of the two contrasting landscapes, with AVS-S to FeS2-S ratios of 2.5 for the Australian and 0.2 in the Finnish sediments. The sediment geochemistry regulated metal mobility. A two-dimensional passive and dynamic hydrogel approach illustrated microniches and supply zones of aluminium iron, manganese and zinc at varying depths near the sediment-water interface. The measurement of bioaccessibility using an in situ technique in acid sulfate landscapes is a first for both Australia and Finland, and this research provides an important avenue for future water and sediment quality monitoring.

Liquefiable soils are common at ports due to the use of hydraulic fills for construction of waterfront facilities. Liquefaction-induced ground failure can result in permanent ground deformations that can cause loss of foundation support and structural damage. This can lead to substantial repair and/or replacement costs and business interruption losses that can have an adverse effect on the port and the surrounding community. Although numerous soil improvement methods exist for remediating a liquefaction-prone site, many of these methods are poorly suited for developed sites because they could damage existing infrastructure and disrupt port operations. An alternative is to use a passive remediation technique. Treating liquefiable soils with colloidal silica gel via permeation grouting has been shown to resist cyclic deformations and is a candidate to be used as a soil stabilizer in passive mitigation. The small-strain dynamic properties are essential to determine the response to seismic loading. The small-to-intermediate strain shear modulus and damping ratio of loose sand treated with colloidal silica gel was investigated and the influence of colloidal silica concentration was determined. The effect of introducing colloidal silica gel into the pore space in the initial phase of treatment results in a 10% to 12% increase in the small-strain shear modulus, depending on colloidal silica concentration. The modulus reduction curve indicates that treatment does not affect the linear threshold shear strain, however the treated samples reduce at a greater rate than the untreated samples in the intermediate-strain range above 0.01% cyclic shear strain. It was observed that the treated sand has slightly higher damping ratio in the small-strain range; however, at cyclic shear strains around 0.003% the trend reverses and the untreated sand begins to have higher damping ratio. Due to the nature of the colloidal silica gelation process, chemical bonds continue to form with time, thus the effect of aging on the dynamic properties is important. A parametric study was performed to investigate the influence of gel time on the increase in small-strain shear modulus. The effect of aging increases the small-strain shear modulus after gelling by 200 to 300% for the 40-minute-gel time samples with a distance from gelation (time after gelation normalized by gel time) of 1000 to 2000; 700% for the 2-hour-gel time sample with a distance from gelation of 1000; and 200 to 400% for the 20-hour-gel time samples with a distance from gelation of 40 to 100. The treatment of all potentially liquefiable soil at port facilities with colloidal silica would be cost prohibitive. Identifying treatment zones that would reduce the lateral pressure and resulting pile bending moments and displacements caused by liquefaction-induced lateral spreading to prevent foundation damage is an economic alternative. Colloidal silica gel treatment zones of varying size and location were evaluated by subjecting a 3-by-3 pile group in gently sloping liquefiable ground to 1-g shaking table tests. The results are compared to an untreated sample. The use of a colloidal silica treatment zone upslope of the pile group results in reduced maximum bending moments and pile displacements in the downslope row of piles when compared to an untreated sample; the presence of the treatment zone had minimal effect on the other rows of piles within the group.

Soils disturbed by strip mining practices may have increased colloid loads moving to groundwater resources, also enhancing the transport of contaminants into our water resources. We hypothesize that contaminant transport within soils following mining is enhanced by colloid mobility. Two sites were chosen for this study, a 30-year old reclaimed strip mine in southwest Virginia and a recently mined area from eastern Kentucky. Intact reclaimed soil monoliths were retrieved from sandstone derived soils in southwestern Virginia. Reclaimed monoliths from eastern Kentucky were recreated in the lab. Intact undisturbed (native) soil monoliths representing the soils before mining were also sampled for comparison. Biosolids were added to an additional reclaimed monolith at a rate of 20 T/acre. Leaching experiments with deionized water at a rate of 1.0 cm/h involved 6 cycles of 8 hours each, giving each monolith at least 2 pore volumes of leaching. Native soil monoliths from Virginia had an average colloid elution of 857 mg over all cycles, reclaimed soil monoliths had an elution of 1460 mg, reclaimed soil monoliths with spoil material had a colloid elution of 76 mg, and when biosolids were amended to reclaimed soil and spoil monoliths, 870 mg colloids were eluted. Native soil monoliths from eastern Kentucky eluted 7269 mg colloids, reclaimed monoliths from eastern Kentucky eluted 10,935 mg colloids, and reclaimed soils with spoil material eluted no colloids. Lime stabilized biosolids enhanced colloid elution due to high pH dispersing material within the monoliths, while spoil materials with high density and salt content reduced colloid elution. Metal loads in solution were mobilized by DOC, particularly in low sulfate environments, while colloid bound metals increased the total metal loads in the order of Pb > Ni > Cu > Cd > Zn > Cr.

Despite indications that they are potential contaminant transport systems and threats to groundwater quality, very little effort has been invested in comparing contaminant transport behavior of natural environmental nanocolloids and their corresponding macrocolloid fractions in the presence of As, Se, Pb, and Cu contaminants. This study involved physico-chemical, mineralogical, stability and contaminant-transport characterizations of nano- (< 100 nm) and macro-colloids (100-2000 nm) fractionated from three Kentucky soils and one biosolid waste. Particle size was investigated with SEM/TEM and dynamic light scattering. Surface reactivity was estimated using CEC and zeta potential. Mineralogical composition was determined by XRD, FTIR, and thermogravimetric analyses. Sorption isotherms assessed affinities for Cu2+, Pb2+, AsO3-, and SeO4-2 contaminants, while settling kinetics experiments of suspensions at 0, 2 and 10 mg/L contaminants determined stability and transportability potential. Undisturbed 18x30 cm KY Ashton Loam soil monoliths were also used for transport experiments, involving infusion of 50 mg L-1 colloid suspensions spiked with 2 mg L-1 mixed contaminant loads in unsaturated, steady state, unit gradient downward percolation experiments. Overall, nanocolloids exhibited greater stability over corresponding macrocolloids in the presence and absence of contaminants following specific mineralogy trends. Physicochemical characterizations indicated that extensive organic carbon surface coatings and higher Al/Fe:Si ratios may have induced higher stability in the nanocolloid fractions, in spite of some hindrance by nano-aggregation phenomena. In the transport experiments, nanocolloids eluted significantly higher concentrations of colloids, total, and colloid-bound metals than corresponding macrocolloids. Contaminant elutions varied by colloid type, mineralogy and contaminant, with the following sequences: soil-colloids>bio-colloids, smectitic>mixed≥kaolinitic>biosolid, and Se>Pb/Cu≥As. Our findings demonstrate that even though they behave more like nano-aggregates rather than individual nano-particles, nanocolloids may exhibit significantly higher mobility and contaminant transport potential over great distances in subsoil environments than their corresponding macrocolloid fractions.

Cette thèse s'inscrit dans une approche résolument pluridisciplinaire, centrée sur l'étude biogéochimique des cycles d'éléments majeurs - éléments en trace dans les eaux contrôlées par l'activité des microorganismes (piégeage/rélargage par la biomasse ou dégradation de la matière organique dissoute et particulaire). Le caractère innovant de ?ette thèse réside dans l'étude, pour la première fois, de l'impact de l'activité microbienne (minéralisation aerobiques par les bactéries typiques des sols, Pseudomonas) sur les cycles biogéochimiques des éléments grâce à la mise en oeuvre en parallèle d'outils géochimiques, physicochimiques et microbiologiques. Cette étude simultanée des cycles biogéochimiques des éléments et des paramètres d'activité biologique nous permettra de prédire les réponses des systèmes naturels aux changements climatiques et aux interventions humaines (sous forme de pollution organique ou métallique). Les études de terrain ont été accompagnés par des étude plus detaillés en laboratoire des mécanismes réactionnels. Dans le cadre de ce travail, mes efforts ont été consacrés à l'étude physicochimique des processus via la modélisation expérimentale de la dégradation de la matière organique des extraits du sol. Et des recherches des relations quantitatives entre la dégradation de la matière organique par les bactéries hétérotrophes Pseudomonas et les cycles des éléments associés
Multidisciplinary approach for the study of the biogeochemical cycles of the main elements in soils and waters controlled by the activity of microorganisms (by uptake/release of cells or in the process of degradation of dissolved organic matter) was used in the thesis. The innovation of this work is to study the effect of microbial activity (soil typical aerobic bacteria Pseudomonas) on the biogeochemical cycles of elements due to take place geochemical, physical, chemical and microbiological processes. The simultaneous study of the biogeochemical cycles of elements and parameters of biological activity will allow us to predict the response of natural systems to climate change and human-induced disturbance (organic or metallic contamination). Field studies were accompanied by detailed laboratory studies of the reaction mechanisms. The thesis considers to the study of physical and chemical processes using of experimental modeling of the degradation of organic matter in soil extracts and to the study of the quantitative relation between the degradation of organic matter by heterotrophic bacteria Pseudomonas and cycles elements

Prediction of arsenic transport and transformation in soil environment requires understanding the transport mechanisms and proper estimation of arsenic partitioning among all three phases in soil/aquifer systems: mobile colloids, mobile soil solution, and immobile soil solids. The primary purpose of this research is to study natural dissolved organic matter (DOM)/colloid-facilitated transport of arsenic and understand the role of soil derived carriers in the transport and transformation of both inorganic and organoarsenicals in soils. DOM/colloid facilitated arsenic transport and transformation in porous soil media were investigated using a set of experimental approaches including batch experiment, equilibrium membrane dialysis experiment and column experiment. Soil batch experiment was applied to investigate arsenic adsorption on a variety of soils with different characteristics; Equilibrium membrane dialysis was employed to determine the ‘free’ and ‘colloid-bound/complexed’ arsenic in water extracts of chosen soils; Column experiments were also set up in the laboratory to simulate arsenic transport and transformation through golf course soils in the presence and absence of soil-derived dissolved substances. The experimental results revealed that organic matter amendments effectively reduced soil arsenic adsorption. The majority of arsenic present in the soil extracts was associated with small substances of molecular weight (MW) between 500 and 3,500 Da. Only a small fraction of arsenic was associated with higher MW substances (MW > 3,500 Da), which was operationally defined as colloidal part in this study. The association of arsenic and DOM in the soil extracts strongly affected arsenic bioavailability, arsenic transport and transformation in soils. The results of column experiments revealed arsenic complicated behavior with various processes occurring in soils studied, including: soil arsenic adsorption, facilitated arsenic transportation by dissolved substances presented in soil extracts and microorganisms involved arsenic species transformation. Soil organic matter amendments effectively reduce soil arsenic adsorption capability either by scavenging soil arsenic adsorption sites or by interactions between arsenic species and dissolved organic chemicals in soil solution. Close attention must be paid for facilitated arsenic transport by dissolved substances presented in soil solution and microorganisms involved arsenic species transformation in arsenic-contaminated soils.

This study examines the fundamental properties of Colloidal Gas Aphrons, CGA, relevant to its application in soil and groundwater decontamination. It also presents the results of laboratory experiments on the applicability of CGA in treating soils contaminated with organic chemicals. CGA is a collection of spherical, 10 to 100 micron-sized gas bubbles dispersed in an aqueous surfactant solution with a volumetric gas fraction (quality) of at most 0.74. It is characterized by its quality, bubble size, stability and apparent viscosity. The stability can be described by the half life, the time needed for 50% of its liquid phase to separate by gravitational drainage. CGA is a non-Newtonian fluid. The apparent viscosity is higher than that of its liquid or gas phase and increases with increase in quality. At quality above 0.6, CGA is a pseudoplastic fluid and can be modelled by the power law. In this quality range, apparent viscosity decreases with increase in shear rate. Measured apparent viscosity can be as high as 25 centipoise at low shear rates for a CGA quality of 0.72. But at low quality, CGA is best described by the Bingham fluid model. CGA flow through porous media follows the discontinuous fluid flow model with the liquid phase advancing faster than the gas phase. The presence of CGA bubbles causes considerable reduction of effective mobility compared to water flow. The bubbles act to reduce the effective flow area by first blocking the wider pores and re-directing flow to narrower pores. The tenacity of the bubbles in the presence of adequate surfactant molecules account for its flow characteristics in porous media. CGA is more effective in flushing hydrophobic organics from saturated sand-packed columns compared with surfactant flushing. CGA provides the surface active agent needed to lower the interfacial tension of the non-wetting phase and at the same time creates enough viscous force to mobilize any trapped fluid. Its ability to preferentially block large pores in a heterogeneous media and direct fluid flow to smaller pores also contributes to the demonstrated effectiveness as a soil flushing agent.
Ph. D.

La réutilisation des eaux usées traitées pour l’irrigation est globalement acceptée et pratiquée pour faire face à la pénurie d'eau et économiser les ressources de haute qualité. Bien que cette pratique présente des avantages indéniables et contribue à un usage plus durable de l'eau douce, elle n’est pas exempt de problèmes liés à l'impact potentiel sur la qualité des sols récepteurs et sur les cultures de micropolluants contenus dans l'eau réutilisée. Parmi ces polluants, les métaux lourds (ML) en concentrations traces jouent un rôle primordial en raison de leur présence systématique dans l'eau utilisée et de leur persistance une fois libéré dans l'environnement. Le devenir des ML dans les sols peut difficilement être prédit parce que les mécanismes de mobilité à travers les sols sont extrêmement variés et liés à des phénomènes simultanés et très complexes impliquant différents équilibres chimiques. Les ML, comme beaucoup d'autres contaminants, ne sont pas seulement partagé entre la phase immobile (le sol) et les phases mobiles présentes dans l'eau. En effet, les colloïdes et les nanoparticules agissent comme une troisième phase mobile, avec leurs propres propriétés rhéologiques et des vitesses de migrations qui leur sont propres. Ce dernier aspect a été l'un des principaux objectifs d’étude de la thèse. Plusieurs essais expérimentaux ont été menés en irriguant un sol standard selon l'Organisation de coopération et de développement économiques (OCDE) avec une eau usés traités réel et / ou synthétiques, contenant des ML en concentrations traces. Pour chaque test, un sol spécifique (avec différentes teneurs en matière organique) et des eaux usées traitées de composition différente (avec différentes concentrations en métaux traces, de salinité, de la teneur en matière organique pour les eaux usées synthétiques, ou des eaux usées traitées réelles) ont été choisi afin d'évaluer les effets des conditions différentes sur le devenir global des ML. L'augmentation de la matière organique du sol de 2,5 à 10% a linéairement amélioré la mobilité des Cd, Cu et Ni avec une augmentation de la mobilité maximum de 35,6, 43,7 et 49,19% pour le Cd, Cu et Ni, respectivement. Pour la plupart des expériences, les ML ont été capturés dans la couche superficielle du sol (0,5 à 1 cm). Néanmoins, des pics de contamination ont été détectés à des profondeurs différentes dans les couches plus profondes du sol. L’étude de la composition des lixiviats montre des variations de concentrations fonction du métal étudié et des caractéristiques du sol et des eaux usées. Des pics de métaux dans le lixiviat sont apparus en même temps que la libération de la matière et / ou la libération de silicates organiques, ce qui démontre l'implication significative des colloïdes dans le transport des métaux. La concentration en sodium (20 mM) a été démontrée un impact fort sur la réduction de la mobilisation colloïdale et que plus de 95% du métal apporté a été détecté dans la couche superficielle du sol en dépit de sa teneur en matière organique. La salinité affiche donc des effets significatifs. L'irrigation avec des eaux usées traitées présentant une très haute teneur en Ca et Mg (111 et 134 mg / L, respectivement) a abouti à la libération moyenne plus élevée de silicium à partir de la matrice inorganique du sol (8,2 mg / L) par rapport à la faible salinité des eaux usées artificielle (1,9 mg / L). Par conséquent, la mobilisation ultérieure de Cd, Cu, Ni et Zn a été observée lorsque le sol a été irrigué avec des eaux usées traitées réelles. Une caractérisation spectroscopique avancée des lixiviats a été réalisée pour identifier les agrégats colloïdaux libérés par le sol dans le but d’en déterminer leur nature, leurs propriétés chimiques et leur état d'agrégation
Reuse of treated wastewater for agricultural purposes is worldwide accepted and practiced to face water scarcity and save high quality resources. Although such practice has undoubtable advantages and is certainly more sustainable respect to the use of fresh water, it is not exempt from severe concerns related to the potential impact on the receiving soil and on the crops of potentially harmful pollutants contained in the reused water at trace levels. Among these pollutants, trace heavy metals (HMs) play a primary role due to their spread presence in the used water and to their persistence once released in the environment. The fate of HMs in the soils can be hardly predicted as mechanisms of mobility through soils are extremely diverse and related to highly complex simultaneous phenomena and chemical equilibria. HMs, in fact, as many other contaminants, are not only partitioned between the solid immobile and the water mobile phases. Indeed, colloids and nanoparticles act as a third mobile phase, with their own rheological properties and velocity. This latter aspect has been one of the main focus of the thesis. In details the thesis describes the results of several experiments conducted irrigating the OECD standard soil with real and/or synthetic wastewater, containing HMs in trace. For each test a specific soil (e.g. varying the organic matter content) and wastewater composition (e.g. varying the metals concentration, the salinity, the organic matter content, or testing real treated wastewaters) has been chosen in order to evaluate the effects of different conditions on the overall HMs fate. The increase of soil organic matter from 2,5 to 10% linearly enhanced the mobility of Cd, Cu and Ni up to a maximum mobility increase of 35.6, 43.7 and 49.19 % for Cd, Cu and Ni, respectively. In most experiments metals accumulated in the top soil layer (0.5 - 1 cm). Nevertheless peaks of contamination were detected at different depths in the soil deeper layers and at different leaching time in the leachates depending on the metal and on the soil and wastewater characteristics. Peaks of metals in the leachate appeared simultaneously with release of organic matter and/or release of silicates, demonstrating outstanding involvement of colloids in metals transport. Sodium concentration (20mM) decidedly reduced colloidal mobilization whereas more than 95 % of the influent metal was detected in the top layer despite the soil organic matter content. Salinity displayed different effects. The irrigation with real treated wastewater with quite high content of Ca and Mg (111 and 134 mg/L, respectively) resulted in higher average release of silicon from the soil inorganic matrix (8.2 mg/L) compared to the low salinity artificial wastewater (1.9 mg/L). Consequently higher mobilization of Cd, Cu, Ni and Zn was observed when the soil was irrigated with real treated wastewater. An advanced spectroscopical characterization of the leachates was performed to identify such colloidal aggregates. The observation of 3D excitation-emission matrix demonstrated in all the leachates samples the presence of fulvic (230-450 nm ex-em fluorescence area) and humic (330-445 nm ex-em) substances. In this context, a novel analytical method was developed to quantify phenolic substances in soil matrices allowing the monitoring of humic matter migration in soil profiles. The novel method was more accurate and more precise respect to the traditional one, allowing to obtain higher recovery of total phenols in peat soil (15.5 % increase) with a decrease of the coefficient of variation (30.1% decrease). Organic water soluble colloids were extracted from the peat used to prepare the OECD standard soil and characterized. Results of size exclusion chromatography highlighted the supramolecular structure of the extracted organic matter. Such structure was further confirmed through fluorescence and 1H-NMR spectroscopy

Steroidal estrogens in the environment exert toxicological effects at very low concentrations. Furthermore, dissolved and colloidal fractions of soil and manure play an important role in the environmental fate and transport of steroidal estrogens. One objective of this study was to quantify the association of the natural estrogen, 17?-estradiol (E2), with the dissolved fraction and colloidal fraction isolated from liquid swine manure (LSM), soil, and soil+LSM mixtures. The second objective of this study was to evaluate whether the E2 associated with the dissolved fraction/colloidal fraction, dissolved fraction and colloidal fraction of the various media could induce an estrogenic response. Estrogenicity was assessed using an E2 receptor (ER) competitor assay, which provided E2 equivalent concentration (EEQ) of dissolved fraction/colloidal fraction, dissolved fraction and colloidal fraction solutions created from the Soil, Soil+LSM and LSM.

Steroidal estrogens in the environment exert toxicological effects at very low concentrations. Furthermore, dissolved and colloidal fractions of soil and manure play an important role in the environmental fate and transport of steroidal estrogens. One objective of this study was to quantify the association of the natural estrogen, 17β-estradiol (E2), with the dissolved fraction and colloidal fraction isolated from liquid swine manure (LSM), soil, and soil+LSM mixtures. The second objective of this study was to evaluate whether the E2 associated with the dissolved fraction/colloidal fraction, dissolved fraction and colloidal fraction of the various media could induce an estrogenic response. Estrogenicity was assessed using an E2 receptor (ER) competitor assay, which provided E2 equivalent concentration (EEQ) of dissolved fraction/colloidal fraction, dissolved fraction and colloidal fraction solutions created from the Soil, Soil+LSM and LSM.

Pour des raisons environnementales et de santé publique, la remédiation des sites et sols pollués est impérative. Une des techniques in-situ utilisées pour dépolluer des sols présentant une pollution aux hydrocarbures, est l’utilisation de mousse liquide. Grâce à son effet bloquant, la mousse crée une barrière entre l’eau et le polluant, et facilite le pompage de celui-ci. La principale problématique de cette technique est la stabilité de la mousse face à l’huile. Des techniques de renforcement de la mousse en présence d’huile sont développées, notamment grâce à l’ajout de polymère ou de particules solides.Ce travail portera donc sur la formulation d’une mousse résistante à l’huile en milieu poreux, et ce grâce à l’utilisation de polymère ou de particules colloïdales.La première partie de ce travail présente les tests de moussabilité et de stabilité effectués hors milieu poreux, ayant permis de présélectionner les produits nécessaires à l’obtention de telles mousses. Dans une seconde partie, des essais en colonne de milieu poreux ont mené à l’optimisation des conditions d’injection, ainsi qu’au choix final des produits à utiliser. Ils ont montré comment l’ajout de polymère permet d’augmenter la résistance à l’écoulement sans augmenter la force de la mousse, et comment l’ajout de particules renforce la résistance de la mousse face à l’huile. Des essais en pilote 2D ont ensuite été réalisés dans le but de comprendre le déplacement de la mousse en milieu poreux 2D vertical. Grâce aux formulations trouvées en colonne 1D, les expériences 2D effectuées en présence d’huile ont permis de tester le renforcement face à l’huile en deux dimensions. Pour finir, la méthodologie et les contraintes à prendre en compte pour réaliser un essai de pompage 3D sont présentées en perspectives
Given the possible environmental and health issues occurring when facing a hydrocarbon polluted site, soil remediation is necessary. One of the in-situ technique to remediate a Light Non Aqueous Phase Liquid pollution is the use of foam. Because of its blocking effect, foam is able to create a water blocking barrier, to confine water beneath the floating pollutant. However, the main issue with this technique is the stability of foam facing the oily pollutant. Several options are currently under review to reinforce foam against oil, which includes polymer or particles addition.The present study thus describes the work performed to obtain an oil-resistant foam in porous media, with the use of polymer or solid colloidal particles.In the first part of the study, foamability and stability tests were performed in bulk to select a broad range of products used to formulate such foams. Then, sandpacks experiments were realized in 1D columns in order to optimize the foam injection parameters and finalize the choice of surfactant and additives. Column experiments showed how additives impacted foam strength. Polymer addition led to an increased flow resistance without improving foam strength while particles addition proved to reinforce foam resistance against oil. Those results were then applied to carry out 2D-tank experiments to study foam displacement in a vertical two dimensions’ porous medium. The 2D tank also helped to simulate a foam injection below an oily layer and observe foam behaviour. Finally, the methodology and constrains to take into account to perform a pumping test in a 3D-pilot, were presented in the outlook section

A novel multi-coloured method for tracing several different sizes of colloid at once was developed using fluorescently dyed latex polystyrene microspheres and employing a solvent dissolution method (SDM) developed from that used in bio-medical research for the detection of these tracers. The use of this method means that both the breakthrough characteristics, and colloidal mobilisation and deposition patterns within the soil profile, can be investigated as it allows detection of the micro sphere tracers in both water and soil samples. A series of laboratory based rainfall simulation experiments carried out on a four large intact soil cores showed that the four sizes of fluorescent microsphere used in this research (1.2Ilm, O.8Ilm, OAllm and O.2Ilm) could mimic the behaviour of the corresponding size fractions of both TP and MRP extremely successfully, though the correlation was stronger for TP. These experiments also showed that the colloidal and colloid-borne P could make a significant contribution to phosphorus losses from agricultural soils. Further, a high proportion of all four size fractions were found to be molybdate reactive, indicating that current water quality monitoring which uses MRP