Defense Date

2019

Document Type

Thesis

Degree Name

Master of Science

Department

Biology

First Advisor

Leigh McCallister

Second Advisor

Arif Sikder

Third Advisor

Julie Zinnert

Fourth Advisor

Edward Crawford

Abstract

The solid phase of an aquifer has an effect on the aqueous phase; if groundwater quality is degraded by the solid phase of an aquifer this is referred to as geogenic pollution. In this study, the Piney Point aquifer in the Virginia Coastal Plain was assessed for mechanisms that may release anions from the solid to aqueous phases and effect water quality. This was done by conducting leaching experiments modified from Balintova et al. (2013). Piney Point aquifer sediments and groundwaters were also analyzed to give a baseline for these experiments. Sedimentary analysis was found to be consistent with McFarland (2017) and groundwater anion concentrations were found to be less than the U.S. Environmental Protection Agency’s (EPA) established Maximum Contaminant Levels (MCL). Leaching experiments found that low pH environments may lead to the release of fluoride in association with phosphorus in sediments and general release of chloride. Nitrate release mechanisms in confined aquifers require further study, but it appeared as total inorganic carbon was dissolved, sedimentary total nitrogen concentrations increased. Sulfate concentrations in leaching experiments were found to be associated with sulfur concentrations in the solid phases. Furthermore, leaching experiments showed that when sediments are exposed to oxic environments then re-exposed to groundwater, higher concentrations of anions were released to the aqueous phases. This could be a particular issue with sulfate concentrations, which were above the EPA MCL in the majority of sediment samples in all leachate treatments.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

5-8-2019

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