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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #257141

Title: Comparison of aerated marsh-pond-marsh and continuous marsh constructed wetlands for treating swine wastewater

Author
item FORBES, DEAN - North Carolina Agricultural And Technical State University
item REDDY, G - North Carolina Agricultural And Technical State University
item Hunt, Patrick
item POACH, MATTHEW - National Oceanic & Atmospheric Administration (NOAA)
item Ro, Kyoung
item CYRUS, JOHNSELY - North Carolina Agricultural And Technical State University

Submitted to: Journal of Environmental Science and Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/2010
Publication Date: 4/15/2010
Citation: Forbes, D.A., Reddy, G.B., Hunt, P.G., Poach, M.E., Ro, K.S., Cyrus, J.S. 2010. Comparison of aerated marsh-pond-marsh and continuous marsh constructed wetlands for treating swine wastewater. Journal of Environmental Science and Health. 45(7):803-809.

Interpretive Summary: Increased swine production in North Carolina has resulted in greater waste generation and is demanding some emerging new innovative technologies to effectively treat swine wastewater. One of the cost-effective and passive methods to treat swine wastewater is using constructed wetlands. These treatment wetlands can be constructed and managed in different ways. This study assessed the differences in nitrogen (N) removal under two N loads in 3 different wetland systems: aerated marsh-pond-marsh (M-P-M), aerated marsh-covered pond-marsh (M-FB-M), and continuous marsh (CM). The systems were not different in their treatment efficiencies. They all removed about 85% of the N when loaded at 7 kilograms of N per hectare per day. Thus, the selection of the type relative to N removal can be done on other factors such as relative cost.

Technical Abstract: Increased swine production in North Carolina has resulted in greater waste generation and is demanding some emerging new innovative technologies to effectively treat swine wastewater. One of the cost-effective and passive methods to treat swine wastewater is using constructed wetlands. The objective of this study was to evaluate the nitrogen (N) removal under two N loads in 3 different wetland systems: aerated marsh-pond-marsh (M-P-M), aerated marsh-covered pond-marsh (M-FB-M), and continuous marsh (CM) with two days drain and five days flood cycle. Swine wastewater from an anaerobic lagoon was applied to the constructed wetland cells (11 m wide x 40 m length) at two N loading rates of 7 and 12 kg N/ha/day from June to July and August to September 2005, respectively. Weekly inflow and outflow samples were collected for N, P, TS, and COD analysis. Total N reductions (%) at low and high N loading rates were 85.8 and 51.8; 86.3 and 63.3; and 86.2 and 61.8 for M-P-M, M-FB-M, and CM, respectively. Aeration had no significant (P > 0.05) impact on N removal. However, significant (P < 0.05) differences were observed for wetland systems between low and high N loading rates. No difference (P > 0.05) in N reduction was found among wetland systems. Vegetation uptake of N was negligible, ranging from 1.2 to 1.8%. No significant (P > 0.05) differences in TS and COD removal were observed between the wetland systems.