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Geosciences

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2nd Empirical Faculty

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Faculty/Staff

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A sediment leaching experiment was conducted in a controlled laboratory setting. The sediments were collected from a carbonate-rich waste mine tailings site in MO. Dissolved inorganic carbon (DIC), major ions, and stable carbon isotope ratios of DIC (d13CDIC) leachate were analyzed. The purpose was to investigate the carbon dioxide produced from acid neutralization by carbonate-rich sediments that may occur at an acid mine drainage contaminated site (e.g. Neosho County SE Kansas) during the loss of CO2(g) during groundwater discharge. Results show that there is rapid decrease in DIC and an increase in pH during the first 48 hours of leaching the tailings with 0.1N sulfuric acid. The decrease in DIC is due to the loss of excess carbon dioxide CO2(aq) dissolved in water as neutralization is occurring. This loss of CO2(g) leads to a kinetic enrichment of the stable carbon isotopes d13CDIC. The magnitude of the d13CDIC enrichment is shown to depend on the (1) initial concentration of the excess CO2(aq) (at time = t0+1) in the leachate, (2) the amount of DIC and (3) the rate at which the CO2(g) is lost from the reactor. These results are important in our understanding of the long-term effect from the exploitation of natural resources that can generate carbon dioxide in the environment.

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Influence of Sediment Acidification on Water Quality in Carbonate Environments: A Laboratory Experiment

A sediment leaching experiment was conducted in a controlled laboratory setting. The sediments were collected from a carbonate-rich waste mine tailings site in MO. Dissolved inorganic carbon (DIC), major ions, and stable carbon isotope ratios of DIC (d13CDIC) leachate were analyzed. The purpose was to investigate the carbon dioxide produced from acid neutralization by carbonate-rich sediments that may occur at an acid mine drainage contaminated site (e.g. Neosho County SE Kansas) during the loss of CO2(g) during groundwater discharge. Results show that there is rapid decrease in DIC and an increase in pH during the first 48 hours of leaching the tailings with 0.1N sulfuric acid. The decrease in DIC is due to the loss of excess carbon dioxide CO2(aq) dissolved in water as neutralization is occurring. This loss of CO2(g) leads to a kinetic enrichment of the stable carbon isotopes d13CDIC. The magnitude of the d13CDIC enrichment is shown to depend on the (1) initial concentration of the excess CO2(aq) (at time = t0+1) in the leachate, (2) the amount of DIC and (3) the rate at which the CO2(g) is lost from the reactor. These results are important in our understanding of the long-term effect from the exploitation of natural resources that can generate carbon dioxide in the environment.