Detecting a microbial response in sediment of the Dan River following a coal ash spill

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Ashley S. Williams (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Advisor
Parke Rublee

Abstract: Coal ash is the residual material of coal combustion for electricity generation. It contains heavy metals and other pollutants and is generally deposited into reservoir ponds for storage, although it may spill or leach into nearby water and possibly disrupt aquatic communities. In February of 2014, a coal ash spill occurred in the Dan River in Eden, NC. Coal ash contains constituents that may stimulate the growth of mercury methylating bacteria. This study aimed to determine if a microbial response is detectable 1.5 years following the spill using qPCR. We tested three primers targeting mercury methylation. We detected an elevated signal 0.5 km downstream from the spill site relative to some other upstream and downstream locations. However, the highest abundance of amplified targets was observed in the furthest upstream site. We also undertook a survey of bacteria present in a coal ash sample from the coal ash pond that was the source of the spill, located at the retired Dan River Steam Station in Eden, NC. SSU rDNA extracted from 31 isolated organisms was sequenced and the organisms identified to genus level. The community was predominantly composed of Bacillus and Arthrobacter spp. 14 Isolates were grown in 50% nutrient broth amended with heavy metals commonly found in coal ash waste (As, Cd, Cr, Hg, Pb, Se, Zn) at environmentally relevant concentrations to characterize their metal tolerance. Overall, 1) we could not confirm a spike in our mercury markers, and 2) coal ash isolates exhibited metal tolerance.

Additional Information

Publication
Thesis
Language: English
Date: 2019
Keywords
Coal Ash, Dan River, Environment, Mercury Methylation, Metal Tolerance, Microbial Ecology
Subjects
Coal ash $x Environmental aspects $z Dan River (Va. and N.C.)
River sediments $x Sampling $z Dan River (Va. and N.C.)
Microbial ecology $z Dan River (Va. and N.C.)
Methylmercury $z Dan River (Va. and N.C.)
Dan River (Va. and N.C.)

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