Retention of manganese by a constructed wetland treating drainage from a coal ash disposal site

Conference · Thu Dec 31 04:00:00 EST 1998

OSTI ID:361646

Kerrick, K H; Horner, M ^[1]

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1. Univ. of Pittsburgh, Johnstown, PA (United States). Biology Dept.

A 3,200 m{sup 2} wetland was constructed in 1988 to treat drainage from an ash disposal site at a coal-fired electricity generating plant in western Pennsylvania. Concentrations of Fe and Mn in the drainage range from 30--80 mg/L and 10--20 mg/L, respectively. Acidity levels of 60--180 mg/L and a pH between 5--5.6 are typical. The wetland has always produced a high quality effluent with respect to Fe concentrations (usually less than 1 mg/L) and pH (about 7). Initial performance of the wetland with respect to Mn was encouraging, with reductions in Mn concentrations of over 50% being common during the first six years of operation. The system was modified in 1994 by adding limestone riprap below some dams and covering diversion dikes with limestone. These alterations were followed by a significant improvement in Mn removal by the system, with effluent concentrations seldom exceeding 1 mg/L. Seasonal observations indicate that Mn removal in the wetland slows during the winter. In laboratory studies, wetland limestone increased Mn removal rates by as much as 6--7 times. These rates exhibited a temperature optimum of 27 C. The rate at near 0 C was about one half that at 27 C and the rate fell to near zero at 43 C. This suggests that biological activity associated with the limestone is an important factor in the success of this wetland.

• OSTI ID: 361646
• Report Number(s): CONF-9805185--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
20 FOSSIL-FUELED POWER PLANTS
ASHES
DEMETALLIZATION
FOSSIL-FUEL POWER PLANTS
GROUND DISPOSAL
LEACHATES
LIMESTONE
MANGANESE
SANITARY LANDFILLS
WATER TREATMENT
WETLANDS