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Showing 1 to 20 of 23 for “"PHREEQC"”.
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Modeling Groundwater Denitrification by Ferrous Iron Using PHREEQC
… of aquifer sediments. Geochemical modeling (PHREEQC) was employed to get an insight into the in situ denitrification processes that take place via all the common electron donors. Emphasis was given to Fe(II)-supported denitrification reactions because it has been overlooked in our region. …
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Predicting the time related generation of acid rock drainage from mine waste: a copper case study
… simple geochemical mass transport models such as PHREEQC can be used. PHREEQC V.2 has capabilities to simulate a wide range of processes that include equilibrium controlled reactions, kinetically controlled reactions and 1-D advective-dispersion transport, and has been used in a wide range of …
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Redox-induzierte Speziesverteilung von Arsen im Eisenreduktionsmilieu hervorgerufen durch Catechol
… zu ortho-Chinon wurde in das geochemische Modell PHREEQC eingebaut und geprüft, ob mit diesem Ansatz eine realistische Abbildung der Versuchsergebnisse möglich ist. Die Laborversuche zeigen, dass Catechol in einem System aus Quarzsand und Eisenhydroxid eine leichte, konstante Eisenreduktion …
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Influence of Water Chemistry Parameters on the Dissolution Rate of the Lead (II) Carbonate Hydrocerussite
… expected equilibrium concentrations predicted by PHREEQC using solubility constants from literature for cerussite and hydrocerussite. The geochemical modelling program PHREEQC was used to speciate total dissolved lead equilibrium concentrations under experimental conditions to determine an …
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Direct mixing of geothermal water and condensate into heated groundwater at Nesjavellir power station
… the scaling potential of various mixing ratios. PHREEQC modeling and simulation techniques were employed to determine the optimal mixing ratio that minimizes scaling while maximizing energy utilization. The research findings suggest that mixes containing condensate water potentially decrease the …
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Modeling & Optimization of CO2-Mixture Frost Growth as a Carbon Capture Process & Integration with Sequestration
… in-house model, performed by coupling PHREEQC geochemical modeling with flow and continuity equations, examines the behavior of the injected brine in deep saline aquifers. The model quantifies permeability changes driven by geochemical reactions and fines migration. By linking cryogenic …
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Vorkommen, Speziesverteilung und Transportverhalten von Cyaniden im Grundwasser des Testfeldes Süd
… im Grundwasserleiter. Modellierungen mit PHREEQC (PARKHURST & APPELO 2001) zeigten, dass die beobachtete Speziesverteilung der Cyanide nicht thermodynamischen Gesetzmäßigkeiten folgt. Vielmehr scheint sich die Speziesverteilung unter dem Einfluss eines vermutlich mikrobiellen Abbaus von …
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Geochemical modeling of an aquifer storage and recovery project in Union County, Arkansas
… is to use the geochemical modeling software PHREEQC to simulate the scenario of injecting partially treated surface water from Ouachita River into the Sparta aquifer at the city of El Dorado. Key reactions modeled include the initial mixing of the two waters in the proximal zone, surface …
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Hydrogeochemical and radiometric investigation of the uranium tailings Schneckenstein
… elements in the areas. The hydrochemical model PHREEQC shows high solubility of most of elements. It also shows the change in chemical conditions between the heap materials and the tailing sediments which is characterised by a decrease of the Eh values with depth. This indicates the change of …
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Investigating Bisulfide Sorption onto Bentonite through Laboratory Experiments and Numerical Modelling
… sorption model was developed in PHREEQC assuming that sorption was driven by three key processes: (i) redox reaction with the structural Fe3+ sites, (ii) surface precipitation as iron sulfide, FeS (likely mackinawite), and (iii) surface complexation reactions with surface hydroxyl …
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The synthesis of calcium phosphate from municipal wastewater and its application for the removal of metals from acidic effluents
… Thenceforth, the PH REdox EQuilibrium (PHREEQC) (in C language) was used to substantiate the experimental results. The aqueous samples were characterised using Atomic Absorption Spectrometer (AAS) and anions were ascertained using Ion chromatography (IC). All experiments were done in …
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Geochemical modeling-based prediction of water-rock interaction during aquifer storage and recovery utilizing selected Colorado Front Range aquifers
… the USGS geochemical modeling computer program PHREEQC (PH REdox EQuilibrium). Model results include mixed solution compositions, mineral saturation indices and estimates of mineral mass precipitation during simulated injection. Results of modeling suggest there is limited geochemical water-rock …
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The hydrochemical and isotopic characterization of groundwater in southern Mozambique
… were calculated using the thermodynamic software PHREEQC. All samples were undersaturated with respect to gypsum and halite, suggesting that the conditions were thermodynamically favored for their dissolution. Samples that were from boreholes that plotted in the limestone layers and >40m depth in …
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Μελέτη των συνθηκών που διέπουν την εναπόθεση κρυστάλλων σε ουρολογικές ενδοπροθέσεις : συσχετισμός της εναπόθεσης σε μοντέλα προσομοίωσης του ουροποιητικού με υπερκορεσμένα διαλύματα
… επικαθίσεων. Τέλος, χρησιμοποιήθηκε το λογισμικό Phreeqc Interactive v 2.6 για τον υπολογισμό του υπερκορεσμού των ούρων ασθενών όσον αφορά στο μονοένυδρο οξαλικό ασβέστιο, στον υδροξυαπατίτη και στον βρουσίτη με ικανοποιητικά αποτελέσματα. Δεδομένου ότι ο υπερκορεσμός είναι μία αναγκαία αλλά όχι …
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Investigating the Fate of Mg-bearing Calcium Carbonates During Early Diagenesis
… are also investigated here. Based on Phreeqc modeling of Silurian seawater composition, the saturation indices (SIs) of calcite, aragonite and dolomite increase with increasing temperature (< 65°C), and slightly decrease with increasing pressure. While detectable dolomite was not …
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Examination of hydrated and accelerated carbonated cement-heavy metal mixtures
… modelling using a geochemical code, PHREEQC, and the edited database, was carried out to elucidate the chemical reactions occurring in cement/heavy metal systems. Heavy metals acted as accelerators for hydration of CaO, CaS and Portland cement except that Zn2+ retarded the early-age …
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Mechanistic Modeling, Design, and Optimization of Low Salinity Waterflooding
… model were validated against the following: (1) PHREEQC geochemistry software; (2) North Sea sandstone coreflooding; and (3) Texas sandstone coreflooding. In these tests, validation results were excellent, in terms of average oil saturation, ion evolution and effluent pH profile. Although the …
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Characterisation of Schwertmannite - Geochemical Interactions with Arsenate and Chromate and Significance in Sediments of Lignite Opencast Lakes
… input for calculations of chemical reactions (“PhreeqC”). It was shown that this mineral is the Fe(III)-controlling phase which is in a redox equilibrium with most surface waters. Geochemical analysis of sediment proved that schwertmannite is the primary mineral forming in the AML. It was …
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Mineral sequestration of CO2 by reaction with alkaline residues
… geochemical model based on the freely available PHREEQC algorithm. The software offers the access to databases, which containing thermodynamic constants of all common dissolved species in natural and industrial processes. Experimental assays conducted in an aqueous carbonation reactor (see …
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Investigation of the Iron Oxidation Kinetics in Mantua Reservoir
Irrigation of the municipal cemetery in Brigham City, Utah resulted in stained headstones in 2001 and 2002. The water used in the irrigation came from Mantua reservoir, a medium sized impoundment situated near the mouth of Box Elder Canyon. In order for Brigham City to establish a city wide …
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