Nitrogen removal in a pilot-scale subsurface horizontal flow constructed wetland

itrogen removal in a pilot-scale submerged flow constructed wetland, planted with Phragmites auslralis and receiving domestic wastewaters was investigated for two years (November 1997 -October 1999). Nitrification and denitrification simultaneously occurred in this system, showing the presence ofboth aerobic and anaerobic sites. A second-order polynomial regression fit well (R2 = 0.9414) the experimental values oflog KT versus T-20 in the temperature range 5-27°C. In addition, a linear trend (R2 = 0.7834) could also be used as a first approximation in a narrower temperature range (IO-27°C); the rate constant at 20°C (K20) for ammonium microbial oxidation was 0.3985 d-l, which corresponds to a fully developed root zone.