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United States Department of Agriculture

Agricultural Research Service

Title: Renovation of Nitrate-Enriched Swine Wastewater by Constructed Wetlands

Authors
item Szogi, Ariel - NC STATE UNIV
item Vanotti, Matias
item Rice, J - NC STATE UNIV
item Humenik, Frank - NC STATE UNIV
item Hunt, Patrick

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 26, 1997
Publication Date: N/A

Technical Abstract: Constructed wetlands can remove large amounts of N from swine wastewater (approx. 2,600 kg/ha/yr). However, conversion of ammonia to nitrate (nitrification) appears to be the limiting factor for maximum N removal by wetlands. A microcosm wetland study was established in 1996 to assess the possibility of sequencing nitrification-wetland treatments. Wastewater enriched with nitrate was applied to the microcosm wetland units at a rate of 190 kg nitrate/ha and a retention time of four days. Results showed that wetland treatments removed 80% of the total nitrate applied compared to 14% removal by a control treatment with no plants. This removal potential is equivalent, on an annual basis, to about 14,000 kg N/ha, which is 5.4 times higher than the N removal without nitrification pretreatment. This indicates that the capacity of mass N removal by wetlands can be significantly increased by nitrification pretreatment.

Last Modified: 11/26/2014