Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/1995
Publication Date: N/A
Technical Abstract: Constructed wetlands have been deemed to be a potential technology for the treatment of wastewater from confined-swine production facilities, and high levels of denitrification are required for the treatment of these nitrogen rich wastewaters. Six wetland cells (3.6 by 35 m) were constructed in Duplin Co., NC, in 1992. One set of two cells (in sequence) contained rush hand bulrushes, and another set of two cells contained bur-reed and cattails. The third set of two cells contained soybean grown in saturated soil culture and flooded rice. Denitrification enzyme activity (DEA) measurements were made on soil from the wetlands to determine the relative denitrification potential and rate limiting factors of the various systems during different times of the year. In all systems and times of the year, DEA was enhanced by nitrate but not by carbon additions. The first wetland cell had higher DEA values than the second cell in both bulrushes and cattails. Bulrush soil had higher DEA values than cattail soil. These data indicate that nitrification prior to or early in the treatment sequence is important.