Plant effects on microbial assemblages and remediation of acidic coal pile runoff in mesocosm treatment wetlands
Beverly Collins*, J. Vaun McArthur, Rebecca R. Sharitz
Savannah
River Ecology Laboratory, P.O. Drawer E. Aiken, SC 29802. USA
Received 16 December 2003; received in revised form 8 July 2004; accepted
14 July 2004
Abstract
Constructed
treatment mesocosm wetland systems comprised of an anaerobic wetland followed
by two aerobic wetlands and differing in aerobic wetland composition (real
plants, plastic plants, no plants) and order (shallow aerobic wetland
followed by leep aerobic wetland or vice versa) were compared to determine
if composition or order affect remediation of acidic, metal :ontaminated
water associated with a coal-fired power plant. Aerobic cell composition
was varied to determine if native plants have no function, are only structure
for bacteria, or improve water quality. The anaerobic cells increased
pH from 2.4 to 6.4 and reduced Al, Fe, and Zn by 93-99%. Order of the
aerobic cells did not affect water quality. Cells with real versus plastic
plants had different bacterial assemblages, but these were not clearly
related to water quality differences between the tank types. Cells with
real plants had lower pH and NH4 and higher Fe and Mn, especiallY during
the growing season, than those with plastic plants or without plants.
We conclude that plants do affect water quality, in part because they
affect bacterial assemblages. Planted
aerobic wetlands can help remediate acidic, metal-contaminated water,
but may contribute to lower pH and greater Fe and Mn concentrations in
treatment effluent.
Published by Elsevier B.V.
Keywords: Coal pile runoff basin; Constructed treatment
wetlands; Acidic drainage
SREL Reprint #2800
Collins, B. S., J. V McArthur and R. R. Sharitz. 2004. Plant effects on microbial assemblages and remediation of acidic coal pile runoff in mesocosm treatment wetlands. Ecological Engineering 23:107-115.
