|Humenik, Frank - NC STATE UNIV|
|Rice, Mark - NC STATE UNIV|
Submitted to: Abstract of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: November 10, 2001
Publication Date: N/A
Technical Abstract: Constructed wetlands are an alternative option for animal waste treatment because they are low-cost, passive systems that provide effective nitrogen removal. In constructed wetlands receiving swine wastewater, nitrogen removal by denitrification is nitrate limited. The objective of this research was to determine the treatment potential of constructed wetlands receiving nitrified swine wastewater. Two parallel sets of constructed wetlands (3.6 x 67 meters) were loaded with wastewater at average monthly rates from 8 to 18 kg N/ha/day. From August 2000 to April 2001, partially nitrified wastewater (10 to 50% nitrified) was applied to one set while regular wastewater was applied to the other set of constructed wetlands. The wetlands receiving the partially nitrified wastewater more effectively removed nitrogen (64 to 97% removal) and exhibited lower ammonia volatilization than the wetlands receiving regular wastewater (15 to 54% removal). In September and October, the wetlands receiving partially nitrified wastewater completely removed the applied NOx-N in the first four meters, but the additional nitrogen removal required the rest of the wetland area. This indicates that a smaller wetland can produce similar nitrogen removal if the wastewater was completely nitrified prior to application.