Date of this Version
Ecological Engineering 36 (2010) 1544–1551; doi:10.1016/j.ecoleng.2010.03.014
Anoxic subsurface flow (SSF) constructed wetlands were evaluated for denitrification using nitrified wastewater. The treatment wetlands utilized a readily available organic woodchip-media packing to create the anoxic conditions. After 2 years in operation, nitrate removal was found to be best described by first-order kinetics. Removal rate constants at 20°C (k20) were determined to be 1.41–1.30 d−1, with temperature coefficients (θ) of 1.10 and 1.17, for planted and unplanted experimental woodchip-media SSF wetlands, respectively. First-order removal rate constants decreased as length of operation increased; however, a longer-term study is needed to establish the steady-state values. The hydraulic conductivity in the planted woodchip-media SSF wetlands, 0.13–0.15 m/s, was similar to that measured in an unplanted gravel-media SSF control system.