Effects of thermal and chemical enhancements on the recovery of heavy chlorinated compounds in saturated porous media: Treatability tests and modeling

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Author Correction: SciPy 1.0: fundamental algorithms for scientific computing in Python.

An amendment to this paper has been published and can be accessed via a link at the top of the paper

Array programming with NumPy.

Array programming provides a powerful, compact and expressive syntax for accessing, manipulating and operating on data in vectors, matrices and higher-dimensional arrays. NumPy is the primary array programming library for the Python language. It has an essential role in research analysis pipelines in fields as diverse as physics, chemistry, astronomy, geoscience, biology, psychology, materials science, engineering, finance and economics. For example, in astronomy, NumPy was an important part of the software stack used in the discovery of gravitational waves1 and in the first imaging of a black hole2. Here we review how a few fundamental array concepts lead to a simple and powerful programming paradigm for organizing, exploring and analysing scientific data. NumPy is the foundation upon which the scientific Python ecosystem is constructed. It is so pervasive that several projects, targeting audiences with specialized needs, have developed their own NumPy-like interfaces and array objects. Owing to its central position in the ecosystem, NumPy increasingly acts as an interoperability layer between such array computation libraries and, together with its application programming interface (API), provides a flexible framework to support the next decade of scientific and industrial analysis

Plateforme d'interopérabilité sémantique gérant les terminologies d'interface au sein d'un espace de partage

Session 1 : Construction, peuplement et exploitation d'ontologiesNational audienceLes systèmes d'information de santé (SIS) sont complexes, hétérogènes et sont rarement interopérables, surtout au niveau sémantique. Dans le cadre du projet ANR/TeRSan, nous proposons une plateforme d'interopérabilité sémantique fondée sur les technologies du web sémantique ayant pour objectif de faciliter l'échange d'informations cliniques standardisées entre SIS au sein d'un espace de partage. L'originalité de la plateforme est d'offrir des services adaptables à tout SIS déployé dans un établissement de santé et préservant l'usage de terminologies et de modèles locaux, souvent propriétaires mais adaptés aux professionnels de santé. La plateforme repose sur 1) une modélisation ontologique des standards HL7 de partage d'information clinique, 2) la constitution d'alignements entre terminologies d'interface locales et terminologies de référence et 3) des services sémantiques permettant de transcoder des termes locaux en termes de référence en tenant compte du type de message et du contexte d'échange. Notre approche a été évaluée dans le cadre du développement d'un prototype d'échange inter-établissements d'informations cliniques dans le domaine de la télépathologie pour la demande d'avis d'expert

Projet ATTENA : Développement de mesures de terrain permettant la mise en évidence de l'atténuation naturelle des polluants organiques

National audienceDe nombreux acteurs se trouvent actuellement confrontés au problème de la gestion de sites contaminés et à leur réhabilitation. La mise en place de méthodes de traitement dites classiques peut engendrer des investissements importants et se révéler difficile d'un point de vue technique, voire inefficace, notamment dans le cas de pollutions d'aquifères ou de contamination étendue des sols. A partir de ce constat, la gestion des sites pollués peut être abordée différemment en intégrant une approche alternative privilégiant les mécanismes naturels de dégradation et communément appelée atténuation naturelle surveillée (ANS)

Environmental Soil Remediation and Rehabilitation Existing and Innovative Solutions

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Effects of thermal and chemical enhancements on the recovery of heavy chlorinated compounds in saturated porous media: Treatability tests and modeling

International audienc

Drainage-imbibition tests and pumping of heavy chlorinated solvents in saturated porous media: measurements and modeling of the effects of thermal and chemical enhancement

International audienceRecovery of chlorinated solvents (CSs) as a free product is mainly based on pumping and pumping/skimming (Perez et al., 2014). However, this technique is time consuming and does not allow significant recovery of CSs in the form of free product and associated dissolved emissions (McGuire et al., 2006). Our study focuses on the beneficial effects of thermal and chemical enhancements for recovering free product composed of heavy chlorinated compounds (Hexachlorobutadiene, Hexachloroethane, Perchloroethylene, Pentachlorobenzene, Trichloroethylene…).This study is part of the SILPHES project, financially supported by ADEME (French Environment and Energy Agency) in the framework of the Investing for the Future (“Investissements d'Avenir”).1. Materials and methodsThe rheological parameters of the DNAPL were characterized: density, dynamic viscosity, interfacial tension (water/DNAPL) and contact angles (water/DNAPL). First, the imbibition-drainage tests were conducted in small columns to determine the capillary pressure-saturation functions. Then, the tests were elaborated in a one-dimensional large column, in order to validate the numerical model. Finally, pumping tests at different flow rates were carried out in a 2D tank, in order to improve the processes. These tests were carried out using glass beads of different diameters (0.1 to 1 mm) at different temperatures (10 °C and 45 °C) and with application of different surfactants (SDBS, Triton X-100, Aerosol MA-80, Tween 80). DNAPL flow was monitored using Time Domain Reflectometry (TDR) probes, geophysical probes (induced polarization) and also imaging technique (Light Reflected Method-LRM).Numerical models have been developed using COMSOL Multiphysics® for 1D and 2D cases and the experimental results were compared with simulations.2. Results and DiscussionThe results show that increasing the temperature from 10 to 45 °C decreases the dynamic viscosity of DNAPLs (respectively from 5.5 (±0.2) to 2.8 (±0.08) mPa.s) and has a limited influence on the interfacial tension (12 mN/m) and the contact angles (70 °). However, surfactants reduce the interfacial tensions (from 12 mN/m to 1 mN/m, depending on surfactant nature and concentration).Retention curves of the two-phase system (capillary pressure as a function of water saturation) obtained using small column are compared to various analytical models (Chen et al., 2006). The best correlations are obtained with the van Genuchten - Mualem model and the Brutsaert - Burdine model.These retention curves show that: (i) The residual saturation of DNAPL decreases by 30% with increasing the temperature from 10 to 45 °C; (ii) Adding the surfactants globally decreases the irreducible saturation of water by 25% (i.e., the surfactants can, at constant pressure, increase the mobility of DNAPLs) and; (iii) Aerosol MA-80 decreases the residual saturation by 24%.The pumping experiments using 2D tanks are under way to confirm these data and to estimate the radius of influence and the optimal pumping rate.Finally, the developed two-phase pressure-pressure numerical model accurately reproduces the experiments, in particular, the movements of the water-DNAPL interface.Perez, J., Lang, C., Roure, J. and Baccelli, A.: 2014, Taux d’utilisation et coûts des différentes techniques et filières de traitement des sols et des eaux souterraines pollués en France - synthèse des données 2012, Technical report, Agence de l’Environnement et de la Maîtrise de l’Energie (ADEME) / Ernst & Young, Angers, France. 148 p.McGuire, T., McDade, J. and Newell, C.: 2006, Performance of DNAPL source depletion technologies at 59 chlorinated solvent-impacted sites, Ground Water Monitoring and Remediation 26(1), 73–84.Chen, Z., Huan, G. and Ma, Y.: 2006, Computational methods for multiphase flows in porous media, number 978-0-898716-06-1, Society for industrial and applied mathematics edn, Philadelphia, PA , USA. 531 p

Polluted soil remediation of heavy chlorinated solvents in saturated porous media: effects of thermal and chemical enhancements

International audienc