Bibliografie tematiche / PHREEQC

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Letteratura scientifica selezionata sul tema "PHREEQC"

Autore: Grafiati
Pubblicato: 4 giugno 2021
Ultima modifica: 11 marzo 2023

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Articoli di riviste sul tema "PHREEQC"

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Toran, Laura, e David Grandstaff. "PHREEQC and PHREEQCI: Geochemical Modeling with an Interactive Interface". Ground Water 40, n. 5 (settembre 2002): 462–64. http://dx.doi.org/10.1111/j.1745-6584.2002.tb02528.x.

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Ji, Shu Hua, e Mei Ling Wu. "Study on Simulation of Heavy Metal Transport in Soil Using PHREEQC". Applied Mechanics and Materials 522-524 (febbraio 2014): 153–60. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.153.

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This paper looked back on the current situation about simulation using PHREEQC of heavy metal transport in soil and the current situation of coupling with other value simulation software. On such a base, the feasibility, advantages and problems of heavy metal reactive solute transport in soil using PHREEQC were discussed.
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Huber, Patrick, Christophe Neyret e Eric Fourest. "Implementation of the anaerobic digestion model (ADM1) in the PHREEQC chemistry engine". Water Science and Technology 76, n. 5 (26 maggio 2017): 1090–103. http://dx.doi.org/10.2166/wst.2017.282.

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Anaerobic digestion is state-of-the-art technology to treat sludge and effluents from various industries. Modelling and optimisation of digestion operations can be advantageously performed using the anaerobic digestion model (ADM1) from the International Water Association. The ADM1, however, lacks a proper physico-chemical framework, which makes it difficult to consider wastewater of complex ionic composition and supersaturation phenomena. In this work, we present a direct implementation of the ADM1 within the PHREEQC chemistry engine. This makes it possible to handle ionic strength effects and ion-pairing. Thus, multiple mineral precipitation phenomena can be handled while resolving the ADM1. All these features can be accessed with very little programming effort, while retaining the full power and flexibility of PHREEQC. The distributed PHREEQC code can be easily interfaced with process simulation software for future plant-wide simulation of both wastewater and sludge treatment.
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Parkhurst, David L., e Laurin Wissmeier. "PhreeqcRM: A reaction module for transport simulators based on the geochemical model PHREEQC". Advances in Water Resources 83 (settembre 2015): 176–89. http://dx.doi.org/10.1016/j.advwatres.2015.06.001.

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de Moel, P. J., A. W. C. van der Helm, M. van Rijn, J. C. van Dijk e W. G. J. van der Meer. "Assessment of calculation methods for calcium carbonate saturation in drinking water for DIN 38404-10 compliance". Drinking Water Engineering and Science 6, n. 2 (18 novembre 2013): 115–24. http://dx.doi.org/10.5194/dwes-6-115-2013.

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Abstract. The new German standard on the calculation of calcite saturation in drinking water, DIN 38404-10, 2012 (DIN), marks a change in drinking water standardization from using simplified equations applicable for nomographs and simple calculators to using extensive chemical modeling requiring computer programs. The standard outlines the chemical modeling and presents a dataset with 10 water samples for validating used computer programs. The DIN standard, as well as the Standard Methods 2330 (SM) and NEN 6533 (NEN) for calculation of calcium carbonate saturation in drinking water were translated into chemical databases for use in PHREEQC (USGS, 2013). This novel approach gave the possibility to compare the calculations as defined in the standards with calculations using widely used chemical databases provided with PHREEQC. From this research it is concluded that the computer program PHREEQC with the developed chemical database din38404-10_2012.dat complies with the DIN standard for calculating Saturation Index (SI) and Calcite Dissolution Capacity (Calcitlösekapazität) or Calcium Carbonate Precipitation Potential (CCPP). This compliance is achieved by assuming equal values for molarity as used in DIN (obsolete) and molality as used in PHREEQC. From comparison with widely used chemical databases it is concluded that the use of molarity limits the use of DIN to a maximum temperature of 45 °C. For current practical applications in water treatment and drinking water applications, the PHREEQC database stimela.dat was developed within the Stimela platform of Delft University of Technology. This database is an extension of the chemical database phreeqc.dat and thus in compliance with SM. The database stimela.dat is also applicable for hot and boiling water, which is important in drinking water supply with regard to scaling of calcium carbonate in in-house drinking water practices. SM and NEN proved to be not accurate enough to comply with DIN, because of their simplifications. The differences in calculation results for DIN, SM and NEN illustrate the need for international unification of the standard for calcium carbonate saturation in drinking water.
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de Moel, P. J., A. W. C. van der Helm, M. van Rijn, J. C. van Dijk e W. G. J. van der Meer. "Assessment of calculation methods for calcium carbonate saturation in drinking water for DIN 38404-10 compliance". Drinking Water Engineering and Science Discussions 6, n. 2 (1 agosto 2013): 167–98. http://dx.doi.org/10.5194/dwesd-6-167-2013.

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Abstract (sommario):
Abstract. The new German standard for calcium carbonate saturation in drinking water, DIN 38404-10, 2012 (DIN), marks a change in drinking water standardization from using simplified equations applicable for nomographs and simple calculators to using extensive chemical modeling requiring computer programs. The standard specifies the chemical outlines for the modeling and presents a dataset with 10 water samples for validating used computer programs. The DIN standard, as well as the Standard Methods 2330 (SM) and NEN 6533 (NEN) for calculation of calcium carbonate saturation in drinking water were translated into chemical databases for use in PHREEQC (USGS, 2013). This novel approach gave the possibility to compare the calculations as defined in the standards and internationally accepted chemical databases provided with PHREEQC. From the research it is concluded that the computer program PHREEQC with the developed chemical database din38404-10_2012.dat complies with the DIN standard for calculating Saturation Index (SI) and Calcite Dissolution Capacity (Calcitlösekapazität) or Calcium Carbonate Precipitation Potential (CCPP). This compliance is achieved by assuming equal values for molarity as used in DIN (obsolete) and molality as used in PHREEQC. From comparison with internationally accepted chemical databases it is concluded that the use of molarity limits the use of DIN to a maximum temperature of 45 °C. For current practical applications in water treatment and drinking water applications, the PHREEQC database stimela.dat was developed within the Stimela platform of Delft University of Technology. This database is an extension of the internationally accepted chemical database phreeqc.dat and thus in compliance with Standard Methods 2330. The database stimela.dat is also applicable for hot and boiling water, which is important in drinking water supply with regard to scaling of calcium carbonate in in-house drinking water practices. The SM and NEN proved to be not accurate enough to comply with DIN, because of their simplifications. The differences in calculation results for DIN, SM and NEN illustrate the need for international unification of the standard for calcium carbonate saturation in drinking water.
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Holmes, Niall, Mark Tyrer, Roger West, Aaron Lowe e Denis Kelliher. "Using PHREEQC to model cement hydration". Construction and Building Materials 319 (febbraio 2022): 126129. http://dx.doi.org/10.1016/j.conbuildmat.2021.126129.

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Aris, A. Z., S. M. Praveena, M. H. Abdullah e M. Radojevic. "Statistical approaches and hydrochemical modelling of groundwater system in a small tropical island". Journal of Hydroinformatics 14, n. 1 (12 aprile 2011): 206–20. http://dx.doi.org/10.2166/hydro.2011.072.

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The aquifer of Manukan Island of Borneo, Malaysia had been found to be affected by seawater intrusion associated with excessive groundwater exploitation. This research attempted to characterize the chemistry of an impacted zone in the island using factor analysis (FA), cluster analysis (CA) and a hydrochemical model package (PHREEQC). The factor scores were used to plot the spatial map and to group the relationships among the monitoring wells using CA. The results of FA analysis revealed that the three main processes associated with the seawater intrusion event are aquifer salinization, cation exchange process and redox sequences. Output from the PHREEQC simulation was used to support the findings from the multivariate analysis.
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Abdelaziz, Ramadan, Broder J. Merkel, Mauricio Zambrano-Bigiarini e Sreejesh Nair. "Particle swarm optimization for the estimation of surface complexation constants with the geochemical model PHREEQC-3.1.2". Geoscientific Model Development 12, n. 1 (8 gennaio 2019): 167–77. http://dx.doi.org/10.5194/gmd-12-167-2019.

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Abstract. Sorption of metals on minerals is a key process in treatment water, natural aquatic environments, and other water-related technologies. Sorption processes are usually simulated with surface complexation models; however, identifying numeric values for the thermodynamic constants from batch experiments requires a robust parameter estimation technique that does not get trapped in local minima. Recently, particle swarm optimization (PSO) techniques have attracted many researchers as an efficient and effective optimization technique to find (near-)optimum model parameters in several fields of research. In this work, uranium at low concentrations was sorbed on quartz at different pH, and the hydroPSO R optimization package was used – the first time – to calibrate the PHREEQC geochemical model, version 3.1.2. Results show that thermodynamic parameter values identified with hydroPSO are more reliable than those identified with the well-known parameter estimation (PEST) software, when both parameter estimation software are coupled to PHREEQC using the same thermodynamic input data. In addition, post-processing tools included in hydroPSO were helpful for the correct interpretation of uncertainty in the obtained model parameters and simulated values. Thus, hydroPSO proved to be an efficient and versatile optimization tool for identifying reliable thermodynamic parameter values of the PHREEQC geochemical model.
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Lu, Peng, Guanru Zhang, John Apps e Chen Zhu. "Comparison of thermodynamic data files for PHREEQC". Earth-Science Reviews 225 (febbraio 2022): 103888. http://dx.doi.org/10.1016/j.earscirev.2021.103888.

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Più fonti

Tesi sul tema "PHREEQC"

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Faxö, Alina. "Modellering av oorganiskt kol i boreal jord och vattendrag med hjälp av PHREEQC : Modelling of dissolved inorganic carbon in boreal soils and streams using PHREEQC". Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-256895.

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Syftet med examensarbetet har varit att studera kol i mindre vattendrag med hjälp av jämviktsmodellering i PHREEQC. Fokus har varit dynamik av löst icke organiskt kol (DIC) samt att förstå hur mycket koldioxid (CO2) som avges från mindre vattendrag och om den mängden har signifikant inverkan på den globala kolbalansen. Med hjälp av provtagen data från Krycklans avrinningsområde år 2003-2007 och 2009 har modellering av DIC och pCO2 utförts med målet att se förändring både över säsong och nedströms i ytvattensystemet. För att utvärdera modellen har tillhandahållen data över uppmätt pCO2 använts. Målet var att jämföra modellerade och tillhandahållna pCO2-värden för att se hur väl modellen kunde beskriva verkligheten och om den fungerade bättre för någon plats eller under vissa delar av året. Analysen visade att pCO2-värden för modellen följer uppmätta pCO2-värden förhållandevis bra. Avvikelserna var störst för en av provpunkterna (provpunkt 6). Modellerade pCO2-värden följde de uppmätta pCO2-värden bäst under vårfloden. Modellen och analys av data visade tydliga indikationer på en avgång av CO2 från vattendraget.
The purpose of this Master thesis has been to study carbon flux in creeks. Chemical equilibrium models were produced to this end using PHREEQC. Specifically, dissolved inorganic carbon (DIC) quantities have been studied in order to understand the discharge of carbon dioxide (CO2) from the creek headwaters and how that affects the global carbon balance. Modeling of DIC and pCO2 was conducted using data from 2003-2007 and 2009 sampled at two points in the Krycklan research catchment located in northern Sweden. Seasonal variation of DIC and pCO2 in the two sample points was studied as well as the difference of these quantities between the two points. Evaluation of the model was done in part by comparing predicted pCO2 values with actual values stemming from a previous study leading to an assessment of the validity of the model. One of the sample points showed larger discrepancies between predictedand actual values than the other. Studying the seasonal variation of discrepancies, they were at the minimum during the spring flood. Finally, the analysis showed clear indications of a net CO2 discharge from the creekstretch between the two sample points.
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Thadée, Anne Laure. "Étude des saumures naturelles et industrielles : Approche expérimentale et par modélisation de l'extraction du lithium par évaporation". Thesis, Pau, 2017. http://www.theses.fr/2017PAUU3012/document.

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Le lithium est une matière première en demande croissante suite au fort développement des appareils nomades et des véhicules électriques. Ce manuscrit s’intéresse à la production de lithium à partir d’une ressource naturelle : les saumures lithinifères. Une étude bibliographique sur l’extraction du lithium présent dans les saumures a mis en avant que cette dernière requiert des quantités importantes d’énergie, d’eau et de réactifs. Cela met ainsi en évidence l’enjeu environnemental et la nécessité d’améliorer les procédés existants. A cette fin, la présente étude allie la modélisation à un travail expérimental. Le modèle sélectionné pour calculer les coefficients d’activité des éléments dissous dans les saumures est le modèle de Pitzer (1991). Un travail de paramétrisation a été effectué pour mettre au point une base de données thermodynamiques disposant des éléments nécessaires (propriétés des sels, paramètres d’interaction) à la description des systèmes électrolytiques d’intérêt. Après un travail de validation appuyé sur des données expérimentales issues de la bibliographie, cette base de données, associée au logiciel PhreeqC pour les calculs géochimiques, permet de simuler différentes transformations des saumures (dilution, évaporation, ajout de réactifs). L’outil mis en place a permis d’analyser des scenarios exploratoires de production de zabuyelite (Li2CO3) et d’effectuer une étude de sensibilité des paramètres opératoires. Des travaux expérimentaux sur des saumures modèles ont été effectués sur deux pilotes distincts : une enceinte climatique et une unité d’évaporation. Les techniques d’analyses utilisées pour suivre l’évolution de la composition de la saumure et la qualité des cristaux sont la chromatographie ionique, la DRX et l’EDX. Le modèle mis au point permet de décrire les systèmes salés complexes à l’équilibre à 25°C. Il parvient à décrire les essais dans le pilote d’évaporation du LaTEP à condition que l’on émette l’hypothèse que la zabuyelite ne précipite pas au cours du temps (sursaturation nécessaire). Il pourrait certainement être optimisé au niveau thermodynamique (spéciations, constantes de solubilité), mais également en y ajoutant une dimension cinétique et transferts liquide-vapeur
Lithium is a critical element regarding to the development of portable devices and electric vehicles. This manuscript is dedicated to lithium production from natural lithium bearing brines. A bibliographic review shows that lithium production consumes lots of water, energy and reactive. It underlines environmental issues and the necessity to improve existing processes. In order to achieve this, modeling and experimental work are associated for this study. The Pitzer model (Pitzer, 1991) is used to calculate the activity coefficients of dissolved aqueous species in brines. After parametrization (salt properties, interaction parameters) and validation with experimental data from literature, a database was optimized to allow the description of key electrolytic systems. Associated with phreeQC software, it is possible to simulate transformations of the brine (such as dilution, evaporation, reactions). It can be used as a predictive tool to explore zabuyelite (Li2CO3) production and study the sensibility of the operative parameters (temperature, pH, pCO2). Experimental work on model-brines was done on two separate pilots: a climatic chamber and a crystallization unit. The evolution of the brine composition and quality of crystals produced was monitored by ionic chromatography, XRD and EDX. The model designed in this study can describe the equilibrium of complex brines at 25°C. It can also describe the experiment in the crystallization unit if a hypothesis of supersaturation (Li2CO3) is used. It could be improved thermodynamically with more speciation and solubility constants, and also with kinetics and liquid-vapor transfers
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Sanchez, Thomas. "Etude comparative de la diffusion d'espèces anioniques et cationiques dans les matériaux cimentaires : étude expérimentale et numérique". Thesis, La Rochelle, 2018. http://www.theses.fr/2018LAROS001/document.

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Dans le cadre du projet Cigeo (centre industriel pour le dépôt géologique de déchets radioactifs), le comportement diffusif des radionucléides dans les matériaux cimentaires est un sujet d’étude de l’Andra. Après la fermeture du site d’entreposage de déchets radioactifs, les radionucléides se retrouveront à terme en solution sous forme d’ions. Ils seront alors susceptibles de migrer vers la roche argileuse entourant le site d’entreposage et ses ouvrages en béton seront la première barrière qu'ils rencontreront lors de leur diffusion. Lorsque l'eau provenant de la roche se trouvera en contact avec les ouvrages, cela entrainera une décalcification et une dégradation progressive du matériau cimentaire. De nombreux travaux de recherche traitent de la diffusion d’espèces ioniques dans les matériaux cimentaires. Il existe cependant très peu d'études comparatives sur la diffusion de traceurs différemment chargés dans les matériaux cimentaires à différents états de dégradation, et notamment sur le matériau qui est à l'étude par l'Andra (à base de CEM V). Cette thèse a donc pour objectif d’étudier la diffusion de différentes espèces anioniques, cationiques et neutres dans un matériau cimentaire à base de CEM V à différents états de dégradation. Dans cette optique, un protocole expérimental optimisé a été mis au point et une étude numérique sur un logiciel de transport réactif multi-espèces a été menée. Des essais de diffusion sur des pâtes de ciment à base de ciment CEM I ont d'abord été réalisés afin de calibrer la procédure. Les essais principalement réalisés sont des essais de diffusion accélérée sous champ électrique, appelés aussi essais de migration. Des essais complémentaires de diffusion naturelle, tels que les essais de lixiviation et d’immersion, permettent de valider et de compléter les résultats des essais de migration. On utilise le logiciel PhreeqC (v3.3.12 Ampère prenant en compte l'application d'un champ électrique lors de la diffusion). Il permet de comparer les comportements diffusifs des traceurs utilisés à l’aide d’un facteur unique, appelé facteur de formation F(i) = D(E,i) / D(L,i) qui représente le chemin accessible à la diffusion de l'espèce i. Ce facteur prend en compte la topologie de la microstructure (porosité, tortuosité…) et les phénomènes électro-capillaires d’adsorption. Afin d'affiner notre modèle numérique, nous nous appuyons sur les courbes d’évolution du courant électrique et des concentrations (traceurs et espèces secondaires). L'étude comparative a été réalisée sur des pâtes de ciment puis du béton à base de CEM V. Les pâtes ont été conservées à différents états de dégradation : sain (la solution porale du matériau est riche en alcalins), lixivié (le matériau s’appauvrit en alcalins au contact d'une solution d'eau pure) et dégradé à pH 12,5 (une solution calcaire remplace la solution porale du matériau sans modifier sa microstructure). Il a alors été observé que les espèces ioniques ne diffusaient pas de la même manière suivant leur charge et l’état de dégradation du matériau (donc de la composition de sa solution porale). Cette observation a été confirmée par les essais de diffusion sur du béton, un matériau de microstructure plus complexe. Sur un type de matériau donné, le facteur de formation F(i) varie d'une espèce à l'autre alors que la géométrie macroscopique du matériau est la même. Cela semble donc faire apparaitre des phénomènes microscopiques qui pourraient influencer la diffusion de l'espèce i et qui dépendent de l’espèce étudiée et de la composition de la solution porale du matériau
Radionuclides diffusive behavior in cement materials is one of the topics studied by Andra for the Cigeo project (industrial center for geological disposal of radioactive waste). After the site closure, radionuclides will be released in solution by the end as ionic species. Therefore, it has high potential to migrate to the argillaceous rock surrounding the disposal site and its concrete vaults will be the first barriers against radionuclides diffusion. When water coming from the argillaceous rock is in contact with concrete vaults, it will lead to a decalcification and a progressive degradation of the cement materials. Numerous research works deal with diffusion of ionic species in cement materials. However, there are very few comparative studies about diffusion of tracer differently charged in cement material untainted and at different degraded states, particularly on the material studied by Andra on its Cigeo project (based on CEM V cement). The aim of this thesis is to study ionic diffusion of different anionic, cationic and neutral species in a cement material based on CEM V at different degradation states. In this purpose, an optimized experimental protocol has been developed and a numerical multi-species reactive transport software study has been lead. Firstly, diffusion tests on CEM I cement paste have been carried out in order to calibrate the procedure. Main tests are electrical field applied accelerated diffusion, also named migration tests. Complementary tests of natural diffusion, like in-diffusion or out-diffusion tests, allow us to validate and round off migration test results. We use PhreeqC software (v3.3.12 Ampère taking into account the application of an electrical field during the diffusion). It permits us to compare diffusive behavior of the studied tracers thanks to a unique factor, named formation factor F(i) = D(E,i) / D(L,i), which represents the accessible way for a ionic species i diffusion. This factor takes into account the microstructure topology (porosity, tortuosity…) and electro-capillarity adsorption phenomenon. In order to improve the numerical model, we use electrical current and concentrations (tracer and secondary species) evolution curves. Comparative study has been conducted on cement pastes and concrete based on CEM V. Pastes were stored at different degradation states : untainted (material pore solution full of alkaline), leached (material depleted in alkaline on contact with pure water) and degraded at pH 12.5 (a calcium solution replace the pore solution without modifying microstructure). We notice that ionic species do not diffuse the same way depending on their charge and the material state (it is therefore a function of the pore solution). These observations had been corroborated by diffusion tests on concrete, a material whose microstructure is more complex. On a given material, the formation factor F(i) changes with the studied ionic species, whereas the macroscopic geometry of the material is the same. It seems to emphasize that microscopic phenomenon influence the species diffusion that depends on the species studied, as well as the pore solution composition of the material
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Parsons, Christopher. "Distribution et mobilité de l'arsenic dans les sols : effets de cycles redox successifs". Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00637484.

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L'arsenic est un metalloïde toxique et cancérigène. Ubiquiste dans la pedosphere, il est très sensibleaux fluctuations des conditions redox du sol, ce qui influe significativement sa toxicité et mobilité. Nousétudions le cycle biogéochimique global de l'arsenic, en tenant compte de l'usage croissant des ressources, etpassons en revue l'importance respective de l'arsenic geogénique et anthropogénique dans l'environnement.La contamination à l'arsenic est souvent diffuse dans les bassins sédimentaires de l'Europe. Cependant, desconcentrations dans l'eau interstitielle du sol peuvent être élevées lors de périodes de saturation du solcausées par la monté des eaux souterraines ou les inondations, prévues d'augmenter dû aux changementsclimatiques. La spectrométrie de fluorescence X quantitative et sans standard a été utilisée pour analyserl'arsenic dans des sols relativement contaminés de la plaine alluviale de la Saône au moyen de protocoles depréparation d'échantillons conçus pour optimiser la précision d'analyse et l'exactitude in situ aux bassesconcentrations d'arsenic. L'arsenic dans ces sols est associe aux (hydr)oxydes du fer et de manganèse de lataille d'argile colloïdale. Ceux-ci subissent une dissolution réductrice par les microorganismes lors desinondations, libérant une importante concentration d'arsenic dans la phase aqueuse. Si, par la suite, l'arsenicdégagé n'est pas éliminé avec l'eau de crue évacuée, il est ré-immobilisé pendant l'oxydation du sol et lareprécipitation des oxydes métalliques. Grâce à une combinaison novatrice d'analyses chimiques par voiehumide, d'écologie microbienne, de spectroscopie ainsi que de modélisation thermodynamique et cinétique,nous démontrons que les cycles d'oxydo-réduction séquentiels entraînent une atténuation d'arsenic aqueuxdans des conditions réductrices dû à la coprécipitation croissante, et a une diminution de l'activitémicrobienne causée par l'appauvrissement en matière organique labile. Des processus d'atténuationsimilaires sont observés en l'absence d'activité microbienne pour Cr et As dans des argiles pyriteuses lorsquecelles-ci sont exposés aux oscillations redox provoquées par l'ajout de substances humiques réduites. Ainsi,nous montrons que les effets cumulatifs de cycles redox successifs sont extrêmement importants pour lamobilité de divers contaminants dans l'environnement.
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Almeida, JoÃo Roberto FaÃanha de. "AnÃlise EstatÃstica Multivariada e Modelo GeoquÃmico Inverso no Estudo da Qualidade da Ãgua SubterrÃnea da Bacia de Forquilha em Quixeramobim-CearÃ". Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=3954.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
Os aqÃÃferos aluviais presentes na regiÃo semi-Ãrida do Nordeste brasileiro hospedam importantes recursos hÃdricos naturais para as populaÃÃes que vivem nessa regiÃo, devido a sua excelente qualidade, quando comparado aos aqÃÃferos localizados nas Ãreas de embasamento cristalino. No entanto, constituem recursos frÃgeis, sendo susceptÃveis a processos de degradaÃÃo da sua qualidade por aÃÃes antrÃpicas, variaÃÃes climÃticas ou modificaÃÃes hidrogeolÃgicas. Com o objetivo de identificar e quantificar os principais processos responsÃveis pelo aumento da salinidade observada no aqÃÃfero aluvial durante o perÃodo nÃo chuvoso usou-se, alÃm de estudos hidroquÃmicos (diagramas e estudo de razÃes iÃnicas), a anÃlise estatÃstica multivariada (agrupamento hierÃrquico e discriminante) e a modelagem geoquÃmica inversa. Os diagramas de Piper e Stiff mostraram a classificaÃÃo das Ãguas quanto à presenÃa dos Ãons dominantes, onde as Ãguas aluviais apresentaram caracterÃsticas intermediÃrias entre as Ãguas do aqÃÃfero fissural e Ãgua dos reservatÃrios. Com o diagrama de RAS obteve-se a mesma interpretaÃÃo. As relaÃÃes iÃnicas revelaram forte relaÃÃo das Ãguas aluviais com a litologia da regiÃo e a provÃvel dissoluÃÃo de aerossÃis contendo compostos de MgCl2 nos aqÃÃferos do embasamento cristalino. A anÃlise de agrupamento mostrou as similaridades entre os poÃos, enquanto a anÃlise discriminante ajudou a compreender o processo de salinizaÃÃo no aqÃÃfero aluvial. As modelagens geoquÃmicas inversas realizadas com o PHREEQC identificaram trocas catiÃnicas de CaX2, MgX2, NaX e KX, alÃm de precipitaÃÃes de K-mica e albita e dissoluÃÃes de anortita e K-feldspato, evidenciando a aÃÃo intempÃrica das Ãguas sobre as rochas. A grande dissoluÃÃo de CO2 nas Ãguas aluviais justifica a caracterÃstica bicarbonatada dessas Ãguas. A contribuiÃÃo volumÃtrica de Ãguas do aqÃÃfero fissural, como forma de justificar o aumento da salinidade nos poÃos aluviais, foi estimada entre 1,53% e 27,99% para diferentes pontos, na mÃdia foi de 15,8%. No entanto, esta contribuiÃÃo representa quase 64% da salinidade no aluviÃo.
The alluvial aquifers in the semi-arid region of Brazilâs Northeast host an important natural water resource for the populations that live in that region, owing to its excellent quality, when compared to the crystalline basement rock aquifers. However, they are fragile resources and are susceptible to processes of degradation of quality by anthropic action, climatic changes or hydrogeological modifications. The objective of this research is to identify and quantify the primary processes responsible for the increase in salinity observed in the alluvial aquifers during the dry season. Besides hydrochemical analysis (Piper and Stiff diagrams and ionic relations), multivariate statistical analysis (hierarchical clustering and discriminant analyses) and inverse geochemical modeling were also used. The Piper and Stiff diagrams presented water classification according to dominant ions, where the alluvial water showed intermediate characteristics between the hard-rock basement aquifer water and that from the reservoirs. With the SAR diagram, the same result was observed. The ionic relations revealed a strong relation of the alluvial water with the lithology of the region and the probable dissolution of aerosols containing composites of the MgCl2 type in the aquifers of the crystalline rock shield. Cluster analysis showed the similarities between the wells, whereas discriminant analysis helped to understand the process of salinization in the alluvial aquifer. The inverse geochemical modeling carried out with PHREEQC identified cationic exchanges of CaX2, MgX2, NaX and KX, as well as precipitation of K-mica and albite and dissolutions of anorthite and K-feldspar, evidencing the intemperic action of the water on the rocks. Strong dissolution of CO2 in the alluvial water justifies the bicarbonated characteristics of that water. The volume contribution from crystalline rock aquifer water was estimated as between 1.53% and 27.99% at different points with a mean value of 15.8%. However, this contribution represents nearly 64% of the salinity of the water in the alluvium.
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6

Kasedde, Hillary. "Characterization of Raw Materials for Salt Extraction from Lake Katwe, Uganda". Licentiate thesis, KTH, Mekanisk metallografi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-134708.

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Uganda is well endowed with economic quantities of salt evident in the interstitial brines and evaporite deposits of Lake Katwe, a closed saline lake located in the western branch of the great East African rift valley. Currently, rudimentally methods of salt mining based on solar evaporation of brine continue to be used for salt extraction at the lake. These have proved to be hazardous and unsustainable to the salt miners and the environment. In this work, literature concerning the occurrence of salt and the most common available technologies for salt extraction is documented. Field studies were undertaken to characterize the salt lake deposit and to devise strategies of improving salt mining and extraction from the salt lake raw materials. The mineral salt raw materials (brines and evaporites) were characterized to determine their physical, chemical, mineralogical, and morphological composition through field and laboratory analyses. In addition, laboratory extraction techniques were undertaken to evaluate possibilities of future sustainable salt extraction from the lake deposit. Also, PHREEQC simulations using Pitzer models were carried out to determine the present saturation state of the lake brine and to estimate which salts and the order in which they precipitate from the brine upon concentration by evaporation. Results reveal that the raw materials from the salt lake contain substantial amounts of salt which can be commercialized for optimum production. The brines are highly alkaline and rich in Na+, K+, Cl-, SO42-, CO32-, and HCO3-. Moreover, they contain trace amounts of Mg2+, Ca2+, Br-, and F-. The lake is hydro-chemically of a carbonate type with the brines showing an intermediate transition between Na-Cl and Na-HCO3 water types. The evaporites are composed of halite mixed with other salts such as hanksite, burkeite, trona etc, with their composition varying considerably within the same grades. The laboratory extraction experiments indicate that various types of economic salts such as thenardite, anhydrite, mirabilite, burkeite, hanksite, gypsum, trona, halite, nahcolite, soda ash, and thermonatrite precipitate from the brine of Lake Katwe. The salts crystallize in the order following the sequence starting with sulfates, followed by chlorides and carbonates, respectively. Moreover, thermodynamic modeling in PHREEQC accurately predicted the solubility and sequence of the salt precipitation from the lake brine. Understanding the sequence of salt precipitation from the brine helps to control its evolution during concentration and hence, will lead to an improved operating design scheme of the current extraction processes. The work providesinformation towards future mineral salt exploitation from the salt lake.

QC 20131129

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7

Santiago, Roberto Namor Silva. "Processos hidrogeoquÃmicos em Ãguas subterrÃneas no cristalino em Caucaia/CE. ContribuiÃÃo da modelagem inversa atravÃs do PHREEQC". Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5468.

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Universidade Federal do CearÃ
A interaÃÃo entre a Ãgua subterrÃnea e as rochas, ocorre atravÃs de processos de dissoluÃÃo e precipitaÃÃo que atestam a evoluÃÃo hidroquÃmicas dentro do sistema aqÃÃfero com a influÃncia direta na qualidade da Ãgua. Nesse trabalho, foi utilizado o aplicativo PHREEQC para simular esses processos em Ãguas de 7 poÃos no cristalino coletadas nos perÃodos seco e chuvoso, com o objetivo de identificar a origem da salinidade dessas Ãguas. Os resultados mostram que (i) a salinidade varia no espaÃo e no tempo; (ii) predomina Ãgua do tipo cloretada mista; (iii) o tipo de Ãgua se mantÃm em cada poÃo (iv) a salinidade diminui no perÃodo chuvoso e aumenta no perÃodo seco, atingindo valores caracterÃsticos de cada poÃo, (v) Ãguas saturadas de goetita, hematita e hidrÃxido de ferro III ocorreram em dois poÃos; calcita, dolomita e aragonita em 3 poÃos e hematita em 2 poÃos. No perÃodo seco e chuvoso, ocorreram dissoluÃÃes de anortita e K-feldspato, precipitaÃÃo de K-mica e albita e trocas catiÃnicas dos tipos CaX2, MgX2, NaX e KX. As Ãguas mais salinas estÃo nos poÃos que receberam menores recargas e as diferenÃas nas recargas à caracterÃstica de Ãreas no cristalino.
The interaction between groundwater and rocks, occurs through processes of dissolution and precipitation that attest to the hydrochemical evolution within the aquifer system with direct influence on water quality. In this study, we used the application PHREEQC to simulate these processes in water from seven wells in crystalline collected during dry and wet, with the aim of identifying the origin of the salinity of these waters. The results show that (i) the salinity varies in space and time, (ii) are mainly chlorinated water from the mixed type, (iii) the type of water remains in each well (iv) the salinity decreases during the rainy season and increases in dry period, reaching values characteristic of each well, (v) water-saturated goethite, hematite and iron hydroxide III occurred in two wells, calcite, dolomite and aragonite in three wells and two wells in hematite. In the dry and rainy season, there were dissolution of anorthite and K-feldspar, precipitation of K-mica and albite and cationic exchange types CaX2, MgX2, NaX and KX. The waters are more saline in wells that received minor differences in recharges and refills is characteristic of areas in the lens
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8

Santiago, Roberto Namor Silva. "Processos hidrogeoquímicos em águas subterrâneas no cristalino em Caucaia/CE. Contribuição da modelagem inversa através do PHREEQC". reponame:Repositório Institucional da UFC, 2010. http://www.repositorio.ufc.br/handle/riufc/13672.

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SANTIAGO, Roberto Namor Silva. Processos hidrogeoquímicos em águas subterrâneas no cristalino em Caucaia/CE. Contribuição da modelagem inversa através do PHREEQC. 2010. 77 f. Dissertação (Mestrado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2010.
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The interaction between groundwater and rocks, occurs through processes of dissolution and precipitation that attest to the hydrochemical evolution within the aquifer system with direct influence on water quality. In this study, we used the application PHREEQC to simulate these processes in water from seven wells in crystalline collected during dry and wet, with the aim of identifying the origin of the salinity of these waters. The results show that (i) the salinity varies in space and time, (ii) are mainly chlorinated water from the mixed type, (iii) the type of water remains in each well (iv) the salinity decreases during the rainy season and increases in dry period, reaching values characteristic of each well, (v) water-saturated goethite, hematite and iron hydroxide III occurred in two wells, calcite, dolomite and aragonite in three wells and two wells in hematite. In the dry and rainy season, there were dissolution of anorthite and K-feldspar, precipitation of K-mica and albite and cationic exchange types CaX2, MgX2, NaX and KX. The waters are more saline in wells that received minor differences in recharges and refills is characteristic of areas in the lens.
A interação entre a água subterrânea e as rochas, ocorre através de processos de dissolução e precipitação que atestam a evolução hidroquímicas dentro do sistema aqüífero com a influência direta na qualidade da água. Nesse trabalho, foi utilizado o aplicativo PHREEQC para simular esses processos em águas de 7 poços no cristalino coletadas nos períodos seco e chuvoso, com o objetivo de identificar a origem da salinidade dessas águas. Os resultados mostram que (i) a salinidade varia no espaço e no tempo; (ii) predomina água do tipo cloretada mista; (iii) o tipo de água se mantém em cada poço (iv) a salinidade diminui no período chuvoso e aumenta no período seco, atingindo valores característicos de cada poço, (v) águas saturadas de goetita, hematita e hidróxido de ferro III ocorreram em dois poços; calcita, dolomita e aragonita em 3 poços e hematita em 2 poços. No período seco e chuvoso, ocorreram dissoluções de anortita e K-feldspato, precipitação de K-mica e albita e trocas catiônicas dos tipos CaX2, MgX2, NaX e KX. As águas mais salinas estão nos poços que receberam menores recargas e as diferenças nas recargas é característica de áreas no cristalino.
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9

Rizk, Nancy. "Caractérisation du colmatage chimique et biologique et leurs interactions au sein d’un dispositif de micro-irrigation dans le contexte de la réutilisation des eaux usées épurées en irrigation". Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0224/document.

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Dans un contexte de stress hydrique, la micro-irrigation avec des eaux usées traitées constitue une solution visant à réduire les dépenses en eau. Cependant, le colmatage des goutteurs constitue une contrainte à l’utilisation de ces eaux bien chargées à cause des précipitations chimiques et du développement de biofilm. Les objectifs de cette étude sont de: a) Caractériser la précipitation des sels dissous en fonction des conditions opératoires, b) étudier le développement des biofilms sous différentes conditions hydrodynamiques, c) analyser l’interaction entre le carbonate de calcium et le développement du biofilm. En premier lieu une étude fut conduite sur l’impact de la température le pH et la pression partielle du CO2 sur la précipitation chimique. Cette étude a permis de quantifier l’augmentation de la masse du carbonate de calcium en fonction du pH et de la température. Les résultats expérimentaux ont permis de valider et de calibrer un modèle numérique (PHREEQC) qui permet de prédire la précipitation chimique pour une qualité d’eau donnée dans des conditions opératoire variées. Des expérimentations ont ensuite été réalisées à l’aide d’un banc d’essai d’irrigation pour étudier l’influence du carbonate de calcium sur la croissance des biofilms au niveau des conduites et des goutteurs. En parallèle un réacteur de Taylor-Couette fut utilisé pour étudier l’influence de la contrainte de cisaillement sur le développement des biofilms. Le biofilm a tendance à se développer selon la plus forte contrainte de cisaillement (4.4 Pa comparée à des contraintes de 2.2 et 0.7 Pa). Une précipitation du carbonate de calcium a été observée en interaction avec la croissance du biofilm
In a context of water stress, micro-irrigation with treated wastewater is a solution to reduce water expenditure. However, the clogging of micro-irrigation systems constitutes a constraint on the use of these well-laden waters due to chemical precipitation and the development of biofilm. The objectives of this study are to: a) characterize precipitation of dissolved salts as a function of operating conditions, b) study the development of biofilms under different hydrodynamic conditions and c) analyze the interaction between calcium carbonate and the development of biofilm. First, a study was conducted on the impact of pH, temperature and partial pressure of CO2 on chemical precipitation. This study permits the quantification of the increase in the mass of the precipitate produced in the form of calcite (calcium carbonate) as a function of the increase in pH and temperature. The experimental results allowed validation and calibration of the modeling of the precipitation under PHREEQC’s software. This numerical model allows prediction and quantification of chemical precipitation for a given water quality under various operating conditions. Experiments were then carried out using an irrigation set-up to study the influence of calcium carbonate on the growth of biofilms inside pipes and drippers. In parallel, a Taylor-Couette reactor was used to study the influence of shear stress on the development of biofilms. Biofilm tends to develop under the highest shear stress (4.4 Pa compared to 2.2 and 0.7 Pa). Precipitation of the calcium carbonate in the form of calcite was observed in interaction with the growth of the biofilm
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Cruz, Ingrid Fernandes Dias da. "Modelagem hidrogeoquímica das águas minerais do Parque Salutaris, Paraíba do Sul, RJ". Niterói, 2016. https://app.uff.br/riuff/handle/1/2274.

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Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências - Geoquímica. Niterói, RJ
As águas minerais do Parque Salutaris no município de Paraíba do Sul, região centro-sul do estado do Rio de Janeiro, consistem em um recurso explorado para consumo humano desde 1887. Essas águas são provenientes de aquíferos fissurais com litologias variadas, tais como gnaisse, granulito e diabásio que lhes conferem características hidroquímicas excepcionais. O objetivo desse trabalho foi compreender os processos geoquímicos responsáveis pela mineralização das águas subterrâneas do Parque Salutaris e identificar possíveis riscos quanto ao consumo dessa água pela população. Para tanto, dentro do parque, foi realizado um monitoramento das águas minerais durante 10 meses, a partir de 3 poços tubulares que captam as águas, nas fontes de distribuição dessas águas e em uma cava que acumula água subterrânea dentro de uma gruta. Também foram realizadas amostragens no rio Paraíba do Sul e em uma nascente a montante do parque, como medidas de background. Foram realizadas medidas físico-químicas “in situ” e análises laboratoriais dos íons maiores Na, K, Mg, Ca, Cl, SO4, HCO3, constituintes menores e traços Al, Mn, Fe, e F, dos nutrientes, SiO2, N-NO2, N-NO3 e P-PO4, de coliformes totais e termotolerantes. Para os materiais geológicos considerados produtos do intemperismo na região foram realizadas análises mineralógicas por DRX da fração argila e comparadas com a modelagem das espécies minerais, disponíveis em água através do PHREEQC. Os tipos hidroquímicos das águas foram: águas bicarbonatada sódica na gruta, bicarbonatada sódica a mista para o poço Nilo Peçanha, bicarbonatada mista no poço Alexandre Abraão e bicarbonatada magnesiana a mista no poço Maria Rita. Verificou-se que as concentrações dos íons dissolvidos teriam origens principais a partir do intemperismo químico de minerais como micas, feldspatos, piroxênio e plagioclásio, presentes no embasamento gnáissico e granulítico. A modelagem hidrogeoquímica permitiu identificar que as espécies minerais carbonáticas tendem ao equilíbrio, enquanto os argilominerais e óxidos de ferro tendem a saturação. Os minerais secundários, identificados através do DRX, estão de acordo com a modelagem no PHREEQC, sendo encontrados principalmente a caulinita, gibbsita, goethita, calcita e clorita no material geológico. Também foram confirmadas que concentrações dissolvidas do flúor e manganês possuem origens naturais. Não foi identificado contaminação por efluentes nos poços de captação das águas minerais. A pesquisa considerou a ingestão de flúor e manganês das águas minerais por receptores residenciais na avaliação de risco a saúde humana, sendo constatado que bebês e infantes podem estar submetidos a riscos crônicos no que tange o desenvolvimento de fluorose dentária.
The mineral waters of Salutaris Park, located at the south-central part of Rio de Janeiro State, are exploited for human consumption since 1887. Those waters come from fractured aquifers as gneiss, granulite and diabase, yielding a variety of hydrogeochemical features. The aim of this study was to understand the geochemical processes responsible for the groundwater mineralization of Salutaris Park and identify the possible risks for human health through the population consumption of those waters. The monitoring of mineral waters was carried out in 3 wells and their respective sources of distribution, besides an ancient pit lake located in cave, inside the park. In order to considerate background measures for the mineral waters, were also collected samples from the Paraíba do Sul River and a spring in upstream of the park. The physicochemical parameters were directly measured in the field. In laboratory, were carried out the measures of major ions Na, K, Mg, Ca, Cl, SO4, HCO3, minor and traces constituents as Al, Mn, Fe and F, nutrients, SiO2, N- NO2, N-NO3, P-PO4 and total and fecal coliforms. The mineralogical characterization of the geological materials were performed by DRX of the clay fraction, which was posterior compared to the mineral species indicated by the PHREEQC hydrogeochemical modeling, through the measure of the minerals saturation indexes. Three different hydrochemical water types were identified in the studied area, namely: 1) sodium bicarbonate type from the pit lake; 2) sodium and mixed bicarbonate types from the Nilo Peçanha well; 3) mixed bicarbonate type from Alexandre Abraão well and 4) magnesium bicarbonate and mixed types from Maria Rita well. It is noticed that the increase of the dissolved concentrations is due to the weathering processes of primary minerals, mainly micaceous minerals, K-feldspar, pyroxene and plagioclase, which are the main constituents of the regional rocks (gneisses and granulites). The hydrogeochemical modeling identified the carbonate species are in equilibrium with those waters, while the clay minerals and iron oxides trend to be supersaturated. The secondary minerals, estimated by the DRX, are in according to the PHREEQC modeling, identifying mainly kaolinite, gibbsite, goethite, calcite and chlorite. Based on the results, there was no identification of anthropogenic impacts by effluents in the minerals waters wells. The fluoride and manganese have natural sources, although they present concentrations above of the standard potability. For that reason, in order to the accomplishment of a risk assessment for the mineral waters consumption, considering the fluoride and manganese intake by human beings, it was found that the babies and infants may be subjected to chronic risks of dental fluorosis development.
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Libri sul tema "PHREEQC"

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Parkhurst, David L. User's guide to PHREEQC: A computer program for speciation, reaction-path, advective-transport, and inverse geochemical calculations. Lakewood, Colo: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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L, Parkhurst David. User's guide to PHREEQC (version 2): A computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations. Denver, Colo: U.S. Department of the Interior, U.S. Geological Survey, 1999.

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J, Appelo C. A., e Geological Survey (U.S.), a cura di. User's guide to PHREEQC (version 2): A computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations. Denver, Colo: U.S. Geological Survey, 1999.

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Parkhurst, David L. User's guide to PHREEQC: A computer program for speciation, reaction-path, advective-transport, and inverse geochemical calculations. Lakewood, Co: U.S. Geological Survey, 1995.

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Parkhurst, David L. PHREEQE: A computer program for geochemical calculations. Reston, Va: U.S. Geological Survey, 1990.

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Jones, Phree. Words of Phree. CreateSpace Independent Publishing Platform, 2013.

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Falck, W. E. Two Modified Versions of the Speciation Code PHREEQE for Modelling Macromolecule-proton/cation Interaction. European Communities / Union (EUR-OP/OOPEC/OPOCE), 1991.

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Naeem, Muhammad. Microprocessor based phree-phase PWM inverter. Bradford, 1988.

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Quilters of The Bunco Club: Phree & Rosa. Frame Masters, Ltd., 2014.

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Phrenic neural output during hypoxia: Constant flow ventilation (CFV) vs spontaneous breathing. Ottawa: National Library of Canada = Bibliothèque nationale du Canada, 1992.

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Capitoli di libri sul tema "PHREEQC"

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Jenkner, F. L. "Phrenic Nerve". In Electric Pain Control, 103–7. Vienna: Springer Vienna, 1995. http://dx.doi.org/10.1007/978-3-7091-3447-4_22.

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Yonekawa, Yuko. "Phrenic Nerve Block". In Nerve Blockade and Interventional Therapy, 77–78. Tokyo: Springer Japan, 2019. http://dx.doi.org/10.1007/978-4-431-54660-3_20.

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Raj, Prithvi, Hans Nolte e Michael Stanton-Hicks. "Phrenic Nerve Block". In Illustrated Manual of Regional Anesthesia, 86–93. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-61389-0_14.

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Lippert, Herbert, e Reinhard Pabst. "Inferior phrenic arteries". In Arterial Variations in Man, 24. Munich: J.F. Bergmann-Verlag, 1985. http://dx.doi.org/10.1007/978-3-642-80508-0_9.

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Jankovic, Danilo, e Philip W. H. Peng. "Phrenic Nerve Blockade". In Regional Nerve Blocks in Anesthesia and Pain Therapy, 127–31. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-05131-4_9.

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Braun-Falco, Markus, Henry J. Mankin, Sharon L. Wenger, Markus Braun-Falco, Stephan DiSean Kendall, Gerard C. Blobe, Christoph K. Weber et al. "Phrenic Nerve Palsy". In Encyclopedia of Molecular Mechanisms of Disease, 1642. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-29676-8_8329.

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Khanna, Vinod Kumar. "Diaphragmatic/Phrenic Nerve Stimulation". In Implantable Medical Electronics, 355–65. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-25448-7_19.

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Rehncrona, S., G. Sedin e H. Fodstad. "Apnea: Phrenic Nerve Stimulation*". In Textbook of Stereotactic and Functional Neurosurgery, 2991–97. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-69960-6_180.

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Crabbe, David C. G. "Diaphragmatic Eventration and Phrenic Palsy". In Pediatric Thoracic Surgery, 501–8. London: Springer London, 2009. http://dx.doi.org/10.1007/b136543_40.

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Gupta, Arielle Hodari, e Jeffrey A. Morgan. "Robotic Phrenic Nerve Pacemaker Implantation". In Atlas of Robotic Thoracic Surgery, 167–70. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-64508-7_17.

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Atti di convegni sul tema "PHREEQC"

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Paz-Garcia, Juan Manuel, Raquel Maria Sanchez-Varo, Pablo Daniel Franco-Caballero, Juan Jose Fernandez-Valenzuela e Maria Villen-Guzman. "HYDROGEOCHEMICAL MODELING OF CONTAMINATED SOILS USING PHREEQC". In 11th International Conference on Education and New Learning Technologies. IATED, 2019. http://dx.doi.org/10.21125/edulearn.2019.1905.

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Jacquemet, N., P. Chiquet e A. Grauls. "Hydrogen Reactivity with (2) an Aquifer - PHREEQC Geochemical Thermodynamics Calculations". In 1st Geoscience & Engineering in Energy Transition Conference. European Association of Geoscientists & Engineers, 2020. http://dx.doi.org/10.3997/2214-4609.202021028.

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Pavuluri, Saideep, Cyprien Soulaine, Francis Claret e Laurent Andre. "Reactive Transport Modelling with a Coupled OpenFOAM®-PHREEQC platform". In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.4620.

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Skolrood, Lydia N., e Jerry D. Allison. "A DATABASE MANAGEMENT TOOL FOR THE PHREEQC AND MINTEQA2 GEOCHEMICAL MODELS". In 66th Annual GSA Southeastern Section Meeting - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017se-290771.

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Jacquemet, N., P. Chiquet e A. Grauls. "Hydrogen Reactivity with (1) a Well Cement - PHREEQC Geochemical Thermodynamics Calculations". In 1st Geoscience & Engineering in Energy Transition Conference. European Association of Geoscientists & Engineers, 2020. http://dx.doi.org/10.3997/2214-4609.202021018.

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Limaluka, Angelo Kennedy Lino, e Yogarajah Elakneswaran. "Coupling of a Reservoir Simulator with Geochemistry for Chemical Enhanced Oil Recovery". In ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/211450-ms.

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Abstract (sommario):
Abstract Chemical enhanced oil recovery (CEOR) techniques are some of the most effective and economical tertiary oil extraction processes. As a key tool for the recovery performance evaluation, reservoir simulation plays an instrumental role in the expansion of the field application of CEOR. However, their framework models essentially the physical aspect of the recovery process. The significant influence of geochemical interactions on the recovery performance remains largely unintegrated. In this study, MATLAB Reservoir Simulation Toolbox (MRST) was coupled with PHREEQC for improved modeling and simulation of polymer flooding and low salinity water flooding (LSWF). The MRST’s polymer model was extended for multi-phase chemical transport by the addition of chemical species in wells boundary conditions, and phase relative permeabilities were modified to account for the wettability alteration effect of the flooding process. In validation, the coupled model showed a good match against PHREEQC in a simulation of a single-phase carbonate core low salinity water flooding (LSWF). It also validated well in the case of matching high salinity experimental results. A demonstrative application of the coupled model in the simulation of LSWF showed 27% maximum incremental oil recovery with a 3.3 mean water-oil ratio (WOR). Furthermore, combining LSWF with polymer flooding achieved the same recovery potential but with much lower water production (0.2 WOR) and doubled production period. These results preliminarily indicate that polymer flooding and LSWF could be combined for at least 27% additional original oil in place (OOIP) recovery with no more than 1 WOR in carbonate reservoirs. However, as this recovery performance evaluation was done in 1D, further work on the coupled model includes improving it for multi-dimensional application.
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Chaabi, Omar, Emad W. Al-Shalabi e Waleed Alameri. "A Numerical Investigation of Low Salinity Polymer Flooding Effects from a Geochemical Perspective". In Offshore Technology Conference. OTC, 2021. http://dx.doi.org/10.4043/31191-ms.

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Abstract Low salinity polymer (LSP) flooding is getting more attention due to its potential of enhancing both displacement and sweep efficiencies. Modeling LSP flooding is challenging due to the complicated physical processes and the sensitivity of polymers to brine salinity. In this study, a coupled numerical model has been implemented to allow investigating the polymer-brine-rock geochemical interactions associated with LSP flooding along with the flow dynamics. MRST was coupled with the geochemical software IPhreeqc. The effects of polymer were captured by considering Todd-Longstaff mixing model, inaccessible pore volume, permeability reduction, polymer adsorption as well as salinity and shear rate effects on polymer viscosity. Regarding geochemistry, the presence of polymer in the aqueous phase was considered by adding a new solution specie and related chemical reactions to PHREEQC database files. Thus, allowing for modeling the geochemical interactions related to the presence of polymer. Coupling the two simulators was successfully performed, verified, and validated through several case studies. The coupled MRST-IPhreeqc simulator allows for modeling a wide variety of geochemical reactions including aqueous, mineral precipitation/dissolution, and ion exchange reactions. Capturing these reactions allows for real time tracking of the aqueous phase salinity and its effect on polymer rheological properties. The coupled simulator was verified against PHREEQC for a realistic reactive transport scenario. Furthermore, the coupled simulator was validated through history matching a single-phase LSP coreflood from the literature. This paper provides an insight into the geochemical interactions between partially hydrolyzed polyacrylamide (HPAM) and aqueous solution chemistry (salinity and hardness), and their related effect on polymer viscosity. This work is also considered as a base for future two-phase polymer solution and oil interactions, and their related effect on oil recovery.
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Meurer, Cullen, Aaron Tigar, Michael S. Bradley, Kara Tafoya, Raymond Johnson e Charles Paradis. "PHREEQC MODELING OF LABORATORY FLOW-THROUGH COLUMN DATA TO INVESTIGATE THE MECHANISMS OF URANIUM MOBILITY". In Joint 55th Annual North-Central / 55th Annual South-Central Section Meeting - 2021. Geological Society of America, 2021. http://dx.doi.org/10.1130/abs/2021nc-362926.

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Seyyedi Nasooh Abad, S. M., e M. Pasdar. "Investigating the Potential of Saline Aquifers for CO2 Mineral Storage - PHREEQC Batch -1D Diffusion-reaction Simulations". In 77th EAGE Conference and Exhibition 2015. Netherlands: EAGE Publications BV, 2015. http://dx.doi.org/10.3997/2214-4609.201413371.

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Farajzadeh, R., T. Matsuura, D. van Batenburg e H. Dijk. "Modeling of Alkali Surfactant Polymer Process by Coupling a Multi-purpose Simulator to the Chemistry Package PHREEQC". In IOR 2011 - 16th European Symposium on Improved Oil Recovery. Netherlands: EAGE Publications BV, 2011. http://dx.doi.org/10.3997/2214-4609.201404789.

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Rapporti di organizzazioni sul tema "PHREEQC"

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HILBERG, Sylke. Abschätzung von Quelleinzugsgebieten mit Hilfe der hydrochemischen Modellierung mittels PHREEQC – Fallbeispiel Reißeck (Oberkärnten). Cogeo@oeaw-giscience, giugno 2010. http://dx.doi.org/10.5242/cogeo.2010.0020.

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Crosland, Richard D. Effect of Arachidonic Acid on Twitch Tension of the Rat Phrenic Nerve- Diaphragm. Fort Belvoir, VA: Defense Technical Information Center, gennaio 1992. http://dx.doi.org/10.21236/ada265570.

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PHREEQCI: A graphical user interface for the geochemical computer program PHREEQC. US Geological Survey, 1997. http://dx.doi.org/10.3133/wri974222.

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User's guide to PHREEQC, a computer program for speciation, reaction-path, advective-transport, and inverse geochemical calculations. US Geological Survey, 1995. http://dx.doi.org/10.3133/wri954227.

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User's guide to PHREEQC (Version 2): A computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations. US Geological Survey, 1999. http://dx.doi.org/10.3133/wri994259.

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