Mercury and copper removal from effluent by constructed treatment wetlands.

Book Title: NA
Year Published: 2004
Month Published: NA
Author: Nelson, E. A. ; Specht, W. L. ; Bowers, J. A. ; Gladden,J. B.
Book Group Author: NA

The A-01 NPDES outfall at the Savannah River Site receives process wastewater discharges and stormwater runoff from the Savannah River Technology Centre. Routine monitoring indicated that copper concentrations were regularly higher than discharge permit limit, necessitating treatment of nearly one million gallons (3.79 million L) of process water each day, plus storm runoff, to meet compliance standards. Constructed in the summer of 2000, the full scale treatment system consists of four pairs of one-acre (0.4 ha) wetland cells (eight acres total; 3.2 ha total) with water flowing from one cell to a second cell, then to the discharge point. The cells are vegetated with Scirpus californicus, and water retention time in the wetland system is approximately 48 hours. Vegetation development within the cells has been excellent, surpassing 2.5 kg/sq. meter of dry aboveground biomass and a density of over 140 shoots per square meter after the 2001 season. Total copper concentration of the inflow to the system has varied up to 180 µg/L (ppb) during the two years of operation, and copper concentrations at the effluent discharge are often below the detection limits (10 µg/L). Most removal of copper from the water is occurring during passage through the first wetland cell. Total mercury concentrations in the system inflow are also variable and have generally ranged between 50 and 100 ng/L (ppt). Mercury levels are sequentially reduced throughout the water path of the wetland system, and mercury concentration at the outfall compliance point is often below 10 ng/L. Copper removal efficiency was excellent from the start-up of the system, while mercury efficiency has improved with maturation of the treatment cells. Operation and maintenance of the system is minimal, and mainly consists of checking for growth of the vegetation and free flow of the water through the system. The system is entirely passive, relying on gravity as the power source of water flow. This treatment system has provided a low cost construction option and a low cost maintenance program for the effective treatment of large volumes of permitted water discharges from an industrial area.

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Journal: NA
Journal ISO: NA
Organization: NA
Publisher: NA
ISSN: 1574771396

artificial wetlands, copper, factory effluents, industrialeffluents, mercury, runoff, water flow, water quality, South Carolina,USA, Scirpus, Cyperaceae, Cyperales, monocotyledons, angiosperms,Spermatophyta, plants, eukaryotes, Scirpus, South Atlantic States ofUSA, Southern States of USA, USA, North America, America, DevelopedCountries, OECD Countries, Southeastern States of USA, Schoenoplectus,constructed wetlands, Schoenoplectus californicus, Scirpus californicus,storm water, United States of America, water composition and quality,Water Resources (PP200), Wetlands (PP320), Pollution and Degradation(PP600), Industrial Wastes and Effluents (XX400)

Source: Web of Science
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