Remediation of coal slurry impoundment liquids using a multi-stage constructed treatment wetland system

Grants and Contracts Details

Description

Over the last 50 years, Kentucky has been one of the three top coal producing states in the US. During this time, most of the coal was mined and processed in 37 eastern KY counties, including Pike, Perry, Harlan, Letcher, Knott, and Floyd counties. The people in this region have greatly benefitted from increased job opportunities and economic development made possible largely by the coal industry. This trend is expected to continue well into the future, as “coal-to-liquids” and “coal-to-natural gas” technologies are advanced, in accordance with strategies 4 and 5 of Gov. Beshear's "Intelligent Energy Choices for Kentucky's Future" energy plan. In this project, we will evaluate a novel approach for disposing of coal waste slurry, which directly supports Topic 5 of this RFP and indirectly supports Topic 8, goals 4 and 5 of KY’s energy plan. Currently, coal that is mined in eastern KY is prepared for burning at combustion plants by crushing and washing with large amounts of water and other agents in order to remove minerals, pyrite, and toxic trace elements, including antimony, arsenic, lead, chromium, copper, and selenium. Each year, this process generates millions of tons of coal waste slurry that contains these trace elements, which ism ostly disposed into basins that are constructed into steeply-sloped mountain valleys. There are about 100 slurry impoundments located in many eastern KY counties http://www.coalimpoundment.org/locate/list.asp), which have the potential to leak or fail with devastating consequences. The overall goal of this project is to test for the first time, the feasibility of using constructed wetlands to reduce the volumes and toxicities of liquid that is stored in slurry impoundments. This goal will be accomplished by circulating liquid obtained from an eastern KY slurry impoundment (in cooperation with a coal preparation plant and KY Division of Abandoned Mine Lands) through a pilot-scale, self-contained, multi-celled treatment wetland system that will be constructed at the University of Kentucky research farm. Trace element levels that emanate from the various cells of the wetland system will be monitored on a weekly basis for one year, and the data will be used to compute first-order pollutant removal rates. Information from the study is required to determine sizes and biogeochemical conditions that are needed in constructed treatment wetlands to reduce pollutant concentrations in impoundments to regulatory target levels so that treated water can be safely released to natural waterways. Thus, the research benefits Local Government Economic Development Fund-Eligible Coal Counties by (i) reducing the threats of impoundments on rural communities and wildlife (Topic 5 of RFP), and (ii) increasing the long-term sustainability of increased coal mining/processing in the region (Topic 8, strategies 4 and 5 of KY’s energy plan). This project brings together a research team composed of a wetland biogeochemist, rhizophere biologist/chemist, trace metal toxicologist, coal petrologist/chemist, environmental engineer and restoration ecologist who are uniquely qualified to make this project a success.
StatusFinished
Effective start/end date5/1/136/30/14

Funding

  • KY Energy and Environment Cabinet: $61,355.00

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