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Zinc transport and partitioning of a mine-impacted watershed: An evaluation of water and sediment quality
Citation:
O'Connor, K., Souhail R. Al-Abed, P. Pinto, AND Phillip M. Potter. Zinc transport and partitioning of a mine-impacted watershed: An evaluation of water and sediment quality. APPLIED GEOCHEMISTRY. Elsevier Science Ltd, New York, NY, 142:105333, (2022). https://doi.org/10.1016/j.apgeochem.2022.105333
Impact/Purpose:
Mining influenced watershed systems can persist for many years after operations are ceased, leading to negative impacts to the health of the surrounding environment. In this study, we look at the heavy metal mobility and speciation of the Spring River Watershed over the years 2014 to 2018 by analyzing the zinc content in water and bed sediments along major tributaries of the system. Results showed total zinc concentrations did not correlate to suspended sediment concentrations and significantly decreased with increased precipitation, suggesting a dilution effect on the zinc content of the stream. By comparing zinc concentrations to surface cover we found a strong positive correlation to pasture lands, suggesting a strong control on zinc mobility in the system. Lastly, zinc speciation found in the water complemented the speciation found in the bed sediments, which were largely composed of zinc phosphate, sulfate, sulfide, and adsorption onto bentonite with lesser amounts of carbonate species. Overall, our findings suggest a complex physiochemical control on zinc concentrations in the system. However, based on the decrease in average total zinc concentrations throughout the five-year collection period the health of the remediated watershed is improving with some of the streams already below the acute and chronic life support criterion established in the region. These results will help provide crucial information to continue the significant remediation effort occurring in the Spring River watershed region.
Description:
Watershed systems influenced by mining waste products can persist for many years after operations are ceased, leading to negative impacts on the health of the surrounding environment. While geochemical behaviors of these trace metals have been studied extensively at the benchtop-scale, much fewer studies have looked at controls on their distributions at the watershed-level. In this study, trace metals (As, Cd, Cr, Cu, Ni, and Zn) were reported from water and stream bed sediments at eight sites between the years 2014–2018 along a watershed undergoing active remediation efforts. Zn was determined to be the only trace metal analyzed with concentrations above EPA and Kansas Department of Health guidelines for both water and sediment in the watershed, and thus was the primary focus for determining the health of the watershed system.
URLs/Downloads:
DOI: Zinc transport and partitioning of a mine-impacted watershed: An evaluation of water and sediment quality
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