METAL REMOVAL FROM PROCESS AND STORMWATER DISCHARGES BY CONSTRUCTED TREATMENT WETLANDS
The A-01 NPDES outfall at the Savannah River Site receives process wastewater and stormwater which passes through a wetland treatment system (WTS) prior to discharge. The overall objective of our research is to better understand the mechanisms of operation of the A-01 WTS in order to provide better input to the design of future systems. The system is a vegetated surface flow wetland and has a retention time of approximately 48 hours. Sampling conducted during the fourth year of operation validated continued wetland performance, and assessed the fate of a larger suite of metals present in the water. Copper and mercury removal efficiencies were still very high, both in excess of 80 per cent removal from the water after passage through the wetland system. Lead removal from the water by the system was 83 per cent, zinc removal was 60 per cent, and nickel was generally unaffected. Nitrates entering into the wetland cells are almost immediately removed from the water column and generally no nitrates are discharged from the A cells. The wetland cells are very anaerobic and the sediments have negative redox potentials. As a result, manganese and iron mineral phases in the sediments have been reduced to soluble forms and increase in the water during passage through the wetland system. Dissolved organic carbon in the water column is also increased by the system and reduces toxicity of the effluent. Operation and maintenance of the system is minimal, and consists of checking for growth of the vegetation and free flow of the water through the system.
- Research Organization:
- Savannah River Site (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC09-96SR18500
- OSTI ID:
- 835623
- Report Number(s):
- WSRC-MS-2004-00763
- Country of Publication:
- United States
- Language:
- English
Similar Records
WasteWater Treatment And Heavy Metals Removal In The A-01 Constructed Wetland 2003 Report
CONSTRUCTED WETLAND TREATMENT SYSTEMS FOR WATER QUALITY IMPROVEMENT