M³: a multiphase, multiconstituant and multiprocess code to model contaminated

70% of the contaminated sites in France are with organic compounds (hydrocarbons, chlorinated solvents,…). Modeling such contamination can be difficult as it is governed by numerous and highly coupled mechanisms (multiphase flow, dissolution and volatilization of Non Aqueous Phase Liquids(NAPL), sorption and biodegradation). Whereas many numerical codes include some of these mechanisms, none of them, to our knowledge, allows the modeling of the full set of mechanisms. A new code, called M3 for Multiphase, Multicomponent, Multiprocess, is then being developed to address this kind of modeling. The originality of the code stands both in the diversity of the mechanisms and in original formalisms such as non-local equilibrium dissolution of NAPL or biodegradation formalism dedicated to chlorinated solvents. After a short description of the numerical code, test cases will be presented to highlight the capacity of the code to model many situations that might be accoutered when dealing with contaminated sites (prediction of an accidental spill, temporal evolution of a source zone and its impact on aquifers, assessment of biodegradation…)

Une approche innovante pour modéliser la biodégradation des composés organochlorés volatils en aquifères poreux

International audienc

CubicM, un code de calcul pour simuler le devenir de polluants organiques dans le milieu souterrain

Le logiciel CubicM est dédié à la modélisation du devenir des polluants organiques dans le milieu souterrain. L'originalité du code tien dans le fait que i)il intègre l'ensemble des mécanismes qui régissent le comportement de ce type de polluants (écoulements triphasiques / transport / dissolution / biodégradation ...); ii) des formalismes mathématiques originaux ont été inclus afin de gagner en précision. Cet outil permet ainsi de modéliser un grand nombre de situations rencontrées sur des sites pollués

Multiphase multicomponent modelling of the NAPL transfer in the subsurface using Method of Lines

This paper presents the three dimensional multicomponent multi-phase simulator CUBICM (M3 ) combining reactive transport and mass transfer modules. The main purpose of this tool is to evaluate and quantify Non-Aqueous Phase Liquid (NAPL) plume attenuation by soil microorganisms and kinetic mass transfer processes such as dissolution, volatilization, sorption. Physical, biological and numerical concepts are given here in a fully embedded method of lines scheme using control volume finite element. The aim of the developed numerical code is to allow a flexible selection of physical formalisms via a dedicated Graphical User Interface in order to study the fate of pollutants in time and space. Various test cases are then illustrated with 2D and 3D semi-realistic heterogeneous configurations

Conditions d’emploi de l’approximation de l’état quasi-stationnaire : cas du réacteur dynamique parfaitement agité

On montre que l’emploi de l’approximation de l’état quasi-stationnaire, lors du calcul d’un réacteur dynamique parfaitement agité à partir d’un mécanisme réactionnel, est légitime pour une réaction non explosive et lorsque le temps de passage est supérieur à une valeur appelée « période d’induction ». On établit les conditions pour lesquelles une réaction devient explosive. On montre que la période d’induction est fonction de la précision de calcul demandée, de la vitesse des processus d’amorçage et des constantes de vitesse des processus de ramification et de terminaison du mécanisme

Assessment for combined phytoremediation and biomass production on a moderately contaminated soil

International audienceOnce previous industrial activity has ceased, brownfields are found in urban and suburban environments and managed in different ways ranging from being left untouched to total reconversion. These situations apply to large surface areas often impacted by residual diffuse pollution. Though significant and preventing any sensitive use, residual contamination does not necessarily require treatment. Moreover, conventional treatments show their technical and economic limits in these situations and gentle remediation options such as phytomanagement might appear more relevant to the management of those sites. Thus, these sites face up two major issues: managing moderate contamination levels and providing an alternative use of economic interest. This work proposes to assess a management strategy associating the phytoremediation of organic pollution along with the production of biomass for energy generation production. A 16-week controlled growth experiment was conducted on a soil substrate moderately impacted by multiple pollution (trace elements, mainly Zn and Pb, and hydrocarbons), by associating rhizodegradation with Medicago sativa or biomass production with Robinia pseudoacacia or Alnus incana in monocultures. The effect of a microbial inoculum amendment on the performances of these treatments was also evaluated. Results showed total hydrocarbons (TH), and to a lesser extent polycyclic aromatic hydrocarbons (PAH), concentrations decreased over time, whatever the plant cover. Good biomass production yields were achieved for both tree species in comparison with the control sample, even though R. pseudoacacia seemed to perform better. Furthermore, the quality of the biomass produced was in conformity with the thresholds set by the legislation concerning its use as a renewable energy source

Tests d'outils innovants pour la caractérisation haute résolution des sites pollués

International audienceLa caractérisation de la pollution du milieu souterrain d’un site est un enjeu essentiel pour définir les actions de remédiation et atteindre les objectifs associés. Parmi les verrous récurrents à cette caractérisation, se situent la complexité des sites, les hétérogénéités géologiques des sols, les grandes différences de comportement et de mobilité des polluants d’intérêts. La compréhension de la distribution des polluants et des contextes physiques dans lesquels ils se situent représente une clé du succès d’une opération de remédiation.La caractérisation des pollutions, par l’intermédiaire d’un prélèvement classique d’eaux souterraines réalisé dans un piézomètre, fournit généralement une information trop partielle pour permettre d’établir un schéma conceptuel de qualité des milieux complexes. Dans pareil cas, des prélèvements multi niveaux et l’acquisition de données complémentaires aux données de qualité chimiques des eaux sont indispensables.Cette étude organise un atelier participatif pour tester différents outils innovants de caractérisation détaillée des matrices souterraines :Mesures de flux de nappe (sens, vitesse …),Mesures multiniveaux de la matrice eau (concentrations, flux…).Les résultats attendus portent sur des connaissances partagées des périmètres d’utilisation de ces outils (typologies de site, géologie, hydrogéologie, contaminants…), des conditions opérationnelles de leur mise en œuvre (conditions d’accès à la technique, facilités d’utilisation, compétences nécessaires, coûts associés, …), de leurs performances techniques (précisions, incertitudes, quantifications, …), de leurs limites (selon les différents contextes de sites…).Cette comparaison doit favoriser l’appropriation d’outils innovants (français et étrangers) pour une caractérisation détaillée de sites pollués (D-L-NAPL), permettant de mieux comprendre les dynamiques et le fonctionnement des systèmes. Elle pourrait permettre de proposer des schémas conceptuels plus précis pour une meilleure connaissance des transferts et une meilleure conception des opérations de remédiation

Chemotherapy of metastatic colon cancer in France: A population-based study

International audienceAims: to describe, using data from a cancer registry in a well-defined French population, the therapeutic strategies and survival of patients with metastatic colon cancer (mCC).Methods: all patients with synchronous mCC diagnosed within the 2005-2014 period recorded in the digestive cancers registry of Burgundy were included.Results: 1286 mCC patients were included (57% male), of which 34.5% did not receive any antitumor treatment. Both, advanced age (≥75 years) and the Charlson comorbidity score ≥2 were significantly associated with the absence of antitumor treatment. Among the patients treated with chemotherapy, 59 and 33% received at least two and three lines, respectively. Most patients treated with chemotherapy (68%) did not receive first-line targeted therapy. Of patients aged ≥75 years, 57% received no chemotherapy and 56% of treated patients had first-line treatment only.Conclusion: this population-based study shows that more than one-third of patients with mCC receive no chemotherapy and that only 59% of treated patients receive treatment beyond the first line. This study also highlights the fact that more than half of patients ≥75 years do not get any antitumor treatment. In patients <75 years, the proportion of patients receiving chemotherapy and/or undergoing curative intent surgery tended to increase over time

M³ : a multiphase, multiconstituant and multiprocess code to model contaminated

International audience70% of the contaminated sites in France are with organic compounds (hydrocarbons, chlorinated solvents,…). Modeling such contamination can be difficult as it is governed by numerous and highly coupled mechanisms (multiphase flow, dissolution and volatilization of Non Aqueous Phase Liquids(NAPL), sorption and biodegradation). Whereas many numerical codes include some of these mechanisms, none of them, to our knowledge, allows the modeling of the full set of mechanisms. A new code, called M3 for Multiphase, Multicomponent, Multiprocess, is then being developed to address this kind of modeling. The originality of the code stands both in the diversity of the mechanisms and in original formalisms such as non-local equilibrium dissolution of NAPL or biodegradation formalism dedicated to chlorinated solvents. After a short description of the numerical code, test cases will be presented to highlight the capacity of the code to model many situations that might be accoutered when dealing with contaminated sites (prediction of an accidental spill, temporal evolution of a source zone and its impact on aquifers, assessment of biodegradation…)

M³ : a multiphase, multiconstituant and multiprocess code to model contaminated

International audience70% of the contaminated sites in France are with organic compounds (hydrocarbons, chlorinated solvents,…). Modeling such contamination can be difficult as it is governed by numerous and highly coupled mechanisms (multiphase flow, dissolution and volatilization of Non Aqueous Phase Liquids(NAPL), sorption and biodegradation). Whereas many numerical codes include some of these mechanisms, none of them, to our knowledge, allows the modeling of the full set of mechanisms. A new code, called M3 for Multiphase, Multicomponent, Multiprocess, is then being developed to address this kind of modeling. The originality of the code stands both in the diversity of the mechanisms and in original formalisms such as non-local equilibrium dissolution of NAPL or biodegradation formalism dedicated to chlorinated solvents. After a short description of the numerical code, test cases will be presented to highlight the capacity of the code to model many situations that might be accoutered when dealing with contaminated sites (prediction of an accidental spill, temporal evolution of a source zone and its impact on aquifers, assessment of biodegradation…)