scholarly journals Reaction of Topopah Spring tuff with J-13 water: a geochemical modeling approach using the EQ3/6 reaction path code

10.2172/59915 ◽  
1985 ◽  
Author(s):  
J.M. Delany
Keyword(s):  
Reaction Path ◽  
Geochemical Modeling ◽  
Modeling Approach ◽  
J 13 ◽  
Topopah Spring Tuff

scholarly journals Geochemical Modeling of Water-Rock Interaction Processes in the Pollino National Park

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
C. Apollaro ◽  
I. Fuoco ◽  
L. Bloise ◽  
E. Calabrese ◽  
L. Marini ◽  
...  
Keyword(s):  
National Park ◽  
Reaction Path ◽  
Geochemical Modeling ◽  
Analytical Data ◽  
Path Modeling ◽  
Rock Interaction ◽  
Interaction Processes ◽  
Comparison Of The Results ◽  
Reaction Path Modeling ◽  
Water Rock Interaction

This work is aimed at reconstructing the water-rock interaction processes controlling the geochemical characteristics of the shallow or relatively shallow groundwaters of the Pollino National Park, based on the data acquired for 105 water samples from local springs. Reaction path modeling of rock dissolution was carried out in a purely stoichiometric mode for the main lithotypes cropping out in the study area, that is, limestone, Mg-limestone, dolomite, serpentinite, Al-silicate fraction of calcschist, and carbonate fraction of calcschist. Reaction path modeling was carried out in a purely stoichiometric mode, considering the rocks of interest as materials of known stoichiometry and unknown thermodynamic properties. Calculations were carried out assuming a closed system for secondary solid phases whereas an open system was assumed for gases, O2(g) and CO2(g). Comparison of the results of geochemical modeling and the analytical data acquired for the groundwaters of the Pollino National Park shows that concentrations of major solutes, SiO2, Li, Al, and Fe of the different chemical types of waters, are explained by the dissolution of pertinent lithotypes. Moreover, the detected concentrations of Al, Cl, F, NO3, and SO4 are within the threshold values recommended by WHO.

Past and future changes to acidified eastern Canadian lakes: A geochemical modeling approach

2007 ◽  
Vol 22 (6) ◽  
pp. 1189-1195 ◽  
Author(s):  
T.A. Clair ◽  
J. Aherne ◽  
I.F. Dennis ◽  
M. Gilliss ◽  
S. Couture ◽  
...  
Keyword(s):  
Geochemical Modeling ◽  
Modeling Approach

Geochemical modeling of chromium oxidation and treatment of polluted waters by RO/NF membrane processes

2020 ◽  
Author(s):  
Ilaria Fuoco ◽  
Alberto Figoli ◽  
Alessandra Criscuoli ◽  
Rosanna De Rosa ◽  
Bartolo Gabriele ◽  
...  
Keyword(s):  
Reaction Path ◽  
Geochemical Modeling ◽  
High Mobility ◽  
Water Type ◽  
Rock Interaction ◽  
Serpentine Minerals ◽  
Path Modelling ◽  
Reaction Path Modelling ◽  
Polluted Waters ◽  
Water Rock Interaction

<p>Geogenic Cr(VI) contamination is a worldwide environmental issue which mainly occurs in areas where ophiolitic rocks crop out. In these areas Cr (VI) can reach high concentrations into groundwaters becoming highly dangerous for human health. Indeed Cr(VI) is recognized as highly toxic element with high mobility and bioavailability [1]. Due to these features, starting from July 2017, Italian government has lowered the Cr(VI) limit value for drinking water to 10 µg/L. To improve the living standards in contaminated areas, it is needed (i) to understand the release and fate of contaminant during the water-rock interaction and (ii) to develop efficient remediation systems for natural polluted waters. In this regard, a complementary study on genesis and treatment of a Cr-rich groundwater coming from Italian ophiolitic aquifers was conducted. Reaction path modelling is a proven geochemical tool to understand the release of Cr and its oxidation from Cr(III) to Cr(VI) during the water-rock interaction. The generally accepted hypothesis of scientific community is that geogenic Cr(III) oxidation  is driven by the reduction of trivalent and tetravalent manganese (Mn(III); Mn (IV)) [2] whereas in this work the role of trivalent Fe hosted in serpentine minerals was re-evaluated. Unlike Mn, Fe is the main oxidant present in suitable amount in these rocks. Literature data confirmed the presence of Fe(III) into serpentine minerals hence reaction path modelling was performed varying the Fe (III)/Fe(tot) ratio ranging  from 0.60 to 1.00. The theoretical paths, reproduce the analytical concentrations of relevant solutes, including Cr(VI), in the Mg-HCO<sub>3</sub> water type hosted in the ophiolitic aquifers of Italy [3]. With increasing of Fe(III)/Fe(tot) ratio in serpentine minerals, high Cr(VI) concentration hold into solution until high alkalinity values. In addition, the spring with the highest Cr(VI) content (75 µg/L) was treated to lower its concentration below the threshold values.  In this work membrane technologies were used as  innovative method considering their many benefits, like the improvement of product quality without using chemicals [4]. A laboratory-scale set-up was used to carry out both Nanofiltration (NF) and Reverse Osmosis (RO) experiments. The experiments were conducted on different commercial membranes: one NF membrane module named DK (polyamide) and two RO membrane modules named AD (polyamide) and CD (cellulose).Tests were performed varying the operating pressures, and high Cr(VI) rejections (around 95%) were reached for all tested membranes, leading to a water containing Cr(VI) in concentrations below the threshold limits. The high flux, obtained already at lower operating pressures (27 L/m<sup>2</sup>h-10bar), combined with high selectivity towards Cr(VI) makes NF a favorable remediation option. The results obtained in this work are in line with the few data available in the literature for natural contaminated waters and there are quite promising for future scientific developments and application.</p><p> </p><p> </p><p>References</p><p>[1]Marinho B. A. et al., 2019. Environ Sci Pollut Res, 26(3), 2203-2227</p><p>[2]Oze C. et al., 2007. Proc. Natl. Acad. Sci. 104, 6544–6549</p><p>[3]Apollaro C. et al., 2019. Sci. Total Environ. 660, 1459-1471</p><p>[4]Figoli  A. & Criscuoli  A., 2017. Springer (Singapore); ISBN:9789811056215</p>

scholarly journals Hydrothermal interaction of Topopah Spring tuff with J-13 water as a function of temperature

10.2172/59346 ◽  
1984 ◽  
Author(s):  
K.G. Knauss ◽  
J.M. Delany ◽  
W.J. Beiriger ◽  
D.W. Peifer
Keyword(s):  
J 13 ◽  
Topopah Spring Tuff
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