Figure - available from: Transport in Porous Media
This content is subject to copyright. Terms and conditions apply.
Oil transmissivity (a) and hydraulic oil conductivity (b) values versus oil saturation using Huntley (2000), Beckett and Lyverse (2002) Bail-down Test Interpretations, and Parker (1987) Analytical Model
Source publication
This paper presents a comparison of hydraulic oil conductivity obtained from interpreting bail-down test data to values calculated from theory. The bail-down tests were performed at laboratory scale, on a radial portion of a circular domain filled with calibrated sand allowing hydraulic oil conductivity to be calculated using Parker’s theoretical m...
Similar publications
The present paper relates to the development of a novel centrifugal pump with lowest specific speed. After a short review of actual developments in the field of low specific speed pumps (e.g. side channel high pressure pump, developments based on the principle of pierced discs and low specific speed API pumps) the design steps for such a high head...
Citations
... The data set comes from a site that is a former automobile manufacturing facility, located in the southwest of France [37][38][39]. The site was operative from 1973 until 2008. ...
The estimation of the soil volume exceeding a contamination threshold over decommissioned industrial sites is critical for the design of remediation strategies. In practice, the volume calculation is mostly based on preliminary sampling surveys and the use of interpolation methods. However, if the volume is not estimated correctly, this can lead to environmental and economic risks. Geostatistical-oriented methodologies have been developed to better assess the volume using uncertainty ranges. In our study, we propose a methodology entitled “Evol” to better estimate the volume and reduce the uncertainty ranges with a combination of classic non-parametrical interpolation techniques and deep learning. Evol consists of generating a synthetic model from a real polluted site, extracting descriptive variables (features) from multiple sample sets, and evaluating the error in the volume calculation. A Deep Neural Network model is then trained with the features to estimate the volume and uncertainty range for any sample set. Our methodology demonstrated high accuracy in error estimation, as evidenced by a low RMSE of 0.008 across most sample sets. Additionally, the confidence volume intervals produced by our approach were narrower than those generated by classic techniques, resulting in interval size reductions of up to 89%.
... However, this type of in situ test is laborious as it requires considerable time and effort to pump and measure the LNAPL, as well as managing the free LNAPL and impacted groundwater pumped during the test. Furthermore, the accurate interpretation of the Bail-Down test data that is used to assess the actual LNAPL thickness is still under discussion (Dippenaar et al. 2005;Batu 2012;Jeong and Charbeneau 2014;Palmier et al. 2017;Ahmed et al. 2019). On the other hand, some analytical models have been proposed for predicting the LNAPL distribution in the subsurface. ...
The present study proposes a methodology for predicting the vertical LNAPL distribution within an aquifer by considering the influence of water table fluctuations. The LNAPL distribution is predicted by combining (i) information on air/LNAPL and LNAPL/water interface elevations with (ii) the initial elevation of the water table without LNAPL effect. Data used in the present study were collected during groundwater monitoring undertaken over a period of four months at a LNAPL-impacted observation well. In this study, the water table fluctuations raised the free LNAPL in the subsurface to an elevation of 206.63 m, while the lowest elevation was 205.70 m, forming a thickness of 0.93 m of LNAPL-impacted soil. Results show that the apparent LNAPL thickness in the observation well is found to be 3 times greater than the actual free LNAPL thickness in soil; a finding that agrees with previous studies reporting that apparent LNAPL thickness in observation wells typically exceeds the free LNAPL thickness within soil by a factor estimated to range between 2 and 10. The present study provides insights concerning the transient variation of LNAPL distribution within the subsurface and highlights the capability of the proposed methodology to mathematically predict the actual LNAPL thickness in the subsurface, without the need to conduct laborious field tests. Practitioners can use the proposed methodology to determine by how much the water table should be lowered, through pumping, to isolate the LNAPL-impacted soil within the unsaturated zone, which can then be subjected to in-situ vadose zone remedial treatment.
... Les parois du dièdre sont collées ensemble au moyen de silicone lipophobe renforcé par du silicone d'aquarium pour permettre le maintien mécanique. Ce pilote a déjà été utilisé pour réaliser des expériences de pompage de flottant (Palmier et al., 2017). Il est fermé par le dessus par un bouchon en PVC maintenu au moyen de vis. ...
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.
... The modified solution (Eq. 1) offered by Huntley [2] is based on the work of Bouwer and Rice [13], in which they offered a solution for the slug test for water. Interpretation of the bail-down test using an analytical solution is under debate [15][16][17][18][19]. Palmier et al. [19] interpreted in an experimental setting that the modified Bouwer and Rice and modified Cooper et al. methods performed well in estimating the oil transmissivity. ...
... The modified solution (Eq. 1) offered by Huntley [2] is based on the work of Bouwer and Rice [13], in which they offered a solution for the slug test for water. Interpretation of the bail-down test using an analytical solution is under debate [15][16][17][18][19]. Palmier et al. [19] interpreted in an experimental setting that the modified Bouwer and Rice and modified Cooper et al. methods performed well in estimating the oil transmissivity. They also suggested that further numerical investigation should be performed under different subsurface conditions and for different fluid properties. ...
Bail-down testing is commonly used to determine the LNAPL transmissivity, volume and initial recovery rate for LNAPL contamination in soil. In this study, a non-compositional three-phase LNAPL/water/air bail-down test model is simulated on the multiphase simulator \(\hbox {DuM}u^x\) (DUNE for Multiphase, Component, Scale, Physics flow and transport in porous media). Field observation data validate the model. Then, different scenarios were simulated to compare the estimated transmissivity using the modified Bouwer and Rice (Huntley in Groundwater 38:46–52, 2000) approach for different soil properties and fluid viscosity. The results show that (1) estimates are reliable for subsurface layers of variable permeability ranges and yield accurate results for low-permeable soil; (2) estimates are sensitive to the Van Genuchten \(\alpha \). Results show poor estimation using low \(\alpha \) values. Employing the modified Bouwer and Rice approach for bail-down test interpretation at sites where the capillary fringe is thick is not recommended; (3) estimates are sensitive to the initial LNAPL thickness \(h_{n}\). Results show that interpretation is not possible if the initial thickness of the contamination is below 1 m for selected parameters; (4) estimates were flawed for low-viscosity fluid and improved as the viscosity of fluid increased; and (5) for scenarios where contamination exists in multilayer soil, the modified Bouwer and Rice approach yields reliable estimates. However, this study tested only one arrangement of this type, wherein the bottom layer consisted of coarse soil.
... These factors are usually related to T n in a complex way: for instance hysteresis impacts the relationships between relative permeability, capillary pressure and saturation, determined by the geological and fluid properties. A 20% difference in T n during imbibition or drainage periods in homogeneous porous media has been documented (Palmier et al., 2017). It is also crucial to assess if the LNAPL is under confined, unconfined or perched conditions since it affects the data analysis methodology. ...
... (Bouwer and Rice, 1976) are not necessarily met for multiphase systems and T n analysis (Batu, 2012). However, several authors have defended this methodology claiming that is robust enough under both field and laboratory conditions (Charbeneau et al., 2013;Palmier et al., 2017), with different analytical solutions presenting a good correlation at field scale under unconfined conditions (Palmier et al., 2016). ...
Water table fluctuations affect the recoverability of light non-aqueous phase liquid (LNAPL) petroleum hydrocarbons. LNAPL transmissivity (Tn) is being applied as an improved metric for LNAPL recoverability. In this paper, the applicability of Tnas a lagging and leading metric in unconsolidated aquifers under variable water table conditions was investigated. Tnvalues obtained through baildown testing and recovery data-based methods (skimming) were compared in three areas of a heterogeneous gasoline contaminated site in Western Australia. High-resolution characterisation methods were applied to account for differences in the stratigraphic profile and LNAPL distribution. The results showed a range of Tnfrom 0 m2/day to 2.13 m2/day, exhibiting a strong spatial and temporal variability. Additionally, observations indicated that Tnreductions may be more affected by the potentiometric surface elevation (Zaw) than by the application of mass recovery technologies. These observations reflected limitations of Tnas a lagging metric and a Remedial Endpoint. On the other hand, the consistency and accuracy of Tnas a leading metric was affected by the subsurface conditions. For instance, the area with a larger vertical LNAPL distribution and higher LNAPL saturations found Tnto be less sensitive to changes in Zawthan the other two areas during the skimming trials. Tnvalues from baildown and skimming tests were generally in a close agreement (less than a factor of 2 difference), although higher discrepancies (by a factor up to 7.3) were found, probably linked to a preferential migration pathway and Zaw. Under stable Zaw, Tnwas found to be a relatively reliable metric. However, variable water table conditions affected Tnand caution should be exercised in such scenarios. Consequently, remediation practitioners, researchers and regulators should account for the nexus between Tn, LNAPL distribution, geological setting and temporal effects for a more efficient and sustainable management of complex contaminated sites.
Contamination by Light Non-Aqueous Phase Liquids (LNAPL) represents a challenge due to the difficulties encountered in its underground assessment and recovery. The major risks arising from subsoil LNAPL accumulation face human health and environment, gaining a social relevance also in the frame of a continuously changing climate. This paper reports on a literature review about the underground contamination by LNAPL, with the aims of providing a categorization of the aspects involved in this topic, analyzing the current state of the art, underlying potential lacks and future perspectives. The review was focused on papers published in the 2012-2022 time-interval, in journals indexed in Scopus and WoS databases, by querying "LNAPL" within article title, abstract and/or key words. 245 papers were collected and classified according to three "key approaches" -namely laboratory activity, field based-data studies and mathematical simulations- and subordinate "key themes", so to allow summarizing and commenting the main aspects based on the application setting, content and scope. Results show that there is a wide experience on plume dynamics and evolution, detection and monitoring through direct and indirect surveys, oil recovery and natural attenuation processes. Few cues of innovations were found regarding both the use of new materials and/or specific field configuration for remediation, and the application of new techniques for plume detection. Some limitations were found in the common oversimplification of the polluted media in laboratory or mathematical models, where the contamination is set within homogeneous porous environments, and in the low number of studies focused on rock masses, where the discontinuous hydraulic behavior complicates the address and modeling of the issue. This paper represents a reference for a quick update on the addressed topic, along with a starting point to develop new ideas and cues for the advance in one of the greatest environmental banes of the current century.
RESUMO Fases líquidas não aquosas leves (LNAPL), como combustíveis líquidos, estão presentes em muitas áreas contaminadas. Para o gerenciamento dessas áreas, é importante conhecer a mobilidade desse produto, a fim de subsidiar decisões sobre sistemas de remediação e avaliação de risco. Uma alternativa para quantificar a mobilidade é o parâmetro transmissividade de LNAPL, ainda pouco aplicado no Brasil. Esse trabalho avaliou a aplicabilidade desse parâmetro em diferentes áreas contaminadas por LNAPL. Foram realizados testes em três áreas com litologias, tipos de contaminantes e históricos de contaminação distintos. Em alguns testes, não foi possível determinar a transmissividade de LNAPL devido à instabilidade do nível de fluidos, por consequência da operação de sistemas de bombeamento e precipitação, além de problemas operacionais durante a realização do teste. Apesar de ser um teste simples, em alguns casos, a determinação de transmissividade de LNAPL pode ser inviável, principalmente para LNAPL de baixa mobilidade por requerer testes mais prolongados. Os principais fatores determinantes no valor de transmissividade de LNAPL foram a litologia, a posição do poço na pluma e a posição do nível d’água em relação a série histórica. Assim, a transmissividade de LNAPL pode ser um parâmetro útil no gerenciamento de áreas contaminadas, cuja interpretação deve ser feita de forma cautelosa e integrada com outros dados de investigação da área.
Les sols et les eaux souterraines contaminés par des hydrocarbures aromatiques polycycliques (HAP) sont une source de préoccupation pour l'environnement et la santé humaine. Les friches d'anciens sites industriels, souvent des usines à gaz et des cokeries, sont les principales zones impactées. Elles sont aujourd'hui proches des zones urbaines ou en font partie et constituent des sources de pollution persistantes qui doivent être dépolluées.Plusieurs techniques de dépollution des sols existent mais elles se concentrent principalement sur la pollution par des HAP purs, tandis que la dépollution des zones faiblement contaminées (à la limite de la saturation résiduelle et le panache de pollution) est souvent trop coûteuse et pas assez efficace pour être réalisée avec succès. La biodégradation des HAP dans le sol est souvent limitée par leur faible biodisponibilité due à une forte sorption sur la matrice solide.Le projet AMI BIOXYVAL vise à élaborer des combinaisons de techniques de dépollution des contaminants organiques persistants en utilisant comme site atelier une ancienne cokerie du nord-est de la France.Cette thèse fait partie de ce projet, et avait pour objectif d'améliorer l'efficacité des procédés de dépollution biologique des HAP en élaborant une combinaison de traitements basés sur le lavage par biosurfactants, afin d'augmenter la solubilité et la biodisponibilité des HAP, et la biodégradation dynamisée.Le prélèvement et l'isolement des bactéries du site atelier ont conduit à la sélection d'un consortium bactérien capable de produire des biosurfactants. La sélection des nutriments, l'optimisation du rapport C/N/P et des paramètres physiques ont permis d'augmenter la production du biosurfactant à l'échelle du laboratoire. Après une montée en l'échelle, dans des bioréacteurs de cinq litres, la purification du biosurfactant a été réalisée et les espèces du consortium bactérien ont été identifiées.En utilisant le consortium et le milieu de production optimisé, des essais de désorption et de biodégradation des HAP ont été effectués dans des réacteurs contenant du sable et de l'eau contaminés, avec un suivi de la production du biosurfactant et de l'évolution de la communauté bactérienne. La production de biosurfactant en présence de HAP a été réalisée avec succès, et la présence de biosurfactant dans les réacteurs a entraîné une augmentation de la solubilité des HAP et de leur biodégradation.Des colonnes dynamiques de sable et de sable + argile ont été réalisées pour comparer la capacité du biosurfactant produit à désorber les HAP avec des surfactants commerciaux d'origines biologique et chimique. Le biosurfactant a montré une meilleure capacité à désorber les HAP que le Tween 80® et qu’un mélange de rhamnolipides ainsi que des taux de désorption proches de ceux du SDS, mais sans les atteindre en raison de quantités injectées plus faibles.La production de biosurfactants par un consortium de bactéries provenant d'un site contaminé pour la mise en œuvre d'un processus de lavage par biosurfactants combiné à un procédé de biodégradation semble être une voie prometteuse pour l'avenir, en raison de la forte capacité du biosurfactant à désorber et à solubiliser les HAP et de la capacité des bactéries productrices de biosurfactants à survivre à la pollution et à dégrader les molécules solubilisées
