Hydrogeochemical Analysis of Processes Through Modeling of Seawater Intrusion Impacts in Biscayne Aquifer Water Quality, USA
Hydrogeochemical processes that accompany seawater intrusion in coastal aquifers can alter the resulting water quality and are important ingredients in coastal aquifer management. The presence of dissolution–precipitation reactions and ion exchange in the mixing zone of the Biscayne aquifer (FL, USA...
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Published in | Aquatic geochemistry Vol. 22; no. 3; pp. 197 - 209 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Dordrecht
Springer Netherlands
01.06.2016
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Hydrogeochemical processes that accompany seawater intrusion in coastal aquifers can alter the resulting water quality and are important ingredients in coastal aquifer management. The presence of dissolution–precipitation reactions and ion exchange in the mixing zone of the Biscayne aquifer (FL, USA) are suggested based on changes in major ion concentrations and mineral saturation indices (SI). Major ion concentrations from 11 groundwater samples are compared with theoretical mixing between freshwater and seawater. PHREEQC code was used to calculate saturation indices of the samples with respect to common phases in the Biscayne aquifer. High Ca
2+
and HCO
3
−
content of the samples is typical of waters in contact with carbonate aquifers. Water quality of the samples is mainly attributed to mixing and precipitation–dissolution reactions with calcite and dolomite. The samples were saturated with calcite (SI ~ 0) and undersaturated for dolomite (SI < 0), while a few samples showed dolomite saturation. Because gypsum and halite SI could be predicted by theoretical mixing, reactions with those minerals, if present, are thought to be insignificant. In the active intrusion areas, cation exchange also appears to modify water quality leading to excess Ca
2+
, but depleted Na
+
, Mg
2+
and K
+
concentrations. On the other hand, samples from previous intrusion areas plotted very close to the theoretical mixing line and approached equilibrium with the seawater. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1380-6165 1573-1421 |
DOI: | 10.1007/s10498-016-9287-1 |