Description of input and examples for PHREEQC version 3: a computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations

Parkhurst, David L.; Appelo, C.A.J.

doi:10.3133/tm6a43

Cited by 2,595 publications

(2,713 citation statements)

References 30 publications

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“…Stoichiometric matrix of aqueous and surface reactions at the calcite-water interface. The parameters ϕ and K are the electrical potentials at the different planes and the equilibrium constants of the reactions, respectively (adapted from the database Phreeqc.dat of the geochemical software Phreeqc [56] and from Heberling et al [10]). …”

Section: Calcite Surface Complexation Modelmentioning

confidence: 99%

Influence of surface conductivity on the apparent zeta potential of calcite

Leroy

Heberling

et al. 2016

Journal of Colloid and Interface Science

114

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Zeta potential is a physicochemical parameter of particular importance in describing the surface electrical properties of charged porous media. However, the zeta potential of calcite is still poorly known because of the difficulty to interpret streaming potential experiments. The HelmholtzSmoluchowski (HS) equation is widely used to estimate the apparent zeta potential from these experiments. However, this equation neglects the influence of surface conductivity on streaming potential. We present streaming potential and electrical conductivity measurements on a calcite powder in contact with an aqueous NaCl electrolyte. Our streaming potential model corrects the apparent zeta potential of calcite by accounting for the influence of surface conductivity and flow regime. We show that the HS equation seriously underestimates the zeta potential of calcite, particularly when the electrolyte is diluted (ionic strength ≤0.01 M) because of calcite surface conductivity. The basic Stern model successfully predicted the corrected zeta potential by assuming that the zeta potential is located at the outer Helmholtz plane, i.e. without considering a stagnant diffuse layer at the calcite-water interface. The surface conductivity of calcite crystals was inferred from electrical conductivity measurements and computed using our basic Stern model. Surface conductivity was also successfully predicted by our surface complexation model.

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Section: Calcite Surface Complexation Modelmentioning

confidence: 99%

Influence of surface conductivity on the apparent zeta potential of calcite

Leroy

Heberling

et al. 2016

Journal of Colloid and Interface Science

114

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“…Recently, PHREEQC has been applied in modeling pollutant adsorption and transport in onedimensional columns importing well-founded thermodynamic database (Parkhurst and Appelo 2013). The water chemistry parameters, GTiO 2 surface properties, adsorptive reactions of As and coexisting ions, and transport parameter modeling are detailed in the electronic supplementary material with a PHREEQC input file with explanation notes (Table S4).…”

Section: Sample Analysismentioning

confidence: 99%

“…Four major interfering ions were identified, Ca 2+ , Mg 2+ , Si, and HCO 3 − , and their effects on As removal were investigated under systematic variation of EBCTs using PHREEQC modeling. This geochemical model (Parkhurst and Appelo 2013), integrating batch adsorptive reactions with one-dimensional reactive transport, accurately predicts the As removal process in column experiments.…”

Section: Introductionmentioning

confidence: 99%

Groundwater arsenic removal using granular TiO2: integrated laboratory and field study

Cui

et al. 2014

Environ Sci Pollut Res

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High concentrations of arsenic (As) in groundwater pose a great threat to human health. The motivation of this study was to provide a practical solution for As-safe water in As geogenic areas using granular TiO 2 (GTiO 2 ). The kinetics results indicated that the As (III/V) adsorption on GTiO 2 conformed to the Weber-Morris (WM) intraparticle diffusion model. The Langmuir isotherm results suggested that the adsorption capacities for As (III) and As (V) were 106.4 and 38.3 mg/g, respectively. Ion effect study showed that cationic Ca and Mg substantially enhanced As (V) adsorption, whereas no significant impact was observed on As (III). Silicate substantially decreased As (V) adsorption by 57 % and As (III) by 50 %. HCO 3 − remarkably inhibited As (V) adsorption by 52 %, whereas it slightly reduced As (III) adsorption by 8 %. Field column results demonstrated that ∼700 μg/L As was removed at an empty bed contact time (EBCT) of 1.08 min for 968 bed volumes before effluent As concentration exceeded 10 μg/L, corresponding to 0.96 mg As/g GTiO 2 . Two household filters loaded with 110 g GTiO 2 in the on-off operational mode can provide 6-L/day As-safe drinking water up to 288 and 600 days from the groundwater containing ∼700 μg/L As and ∼217 μg/L As, respectively. Integration of batch experiments and column tests with systematic variation of EBCTs was successfully achieved using PHREEQC incorporating a charge distribution multisite complexation (CD-MUSIC) model and one-dimensional reactive transport block.

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“…The interactions of Sb(III) and Sb(V) with the soils were modeled using the computer program PHREEQC [32]. The model assumes that Sb(V)/Sb(III) is retained on soil at a set of equilibrium sorption sites interacts instantaneously and a set of reversible kinetic sites are time dependent in nature.…”

Section: Modelingmentioning

confidence: 99%