Removal Effects of N and P in Subsurface Wastewater Infiltration System by Festuca aroundinaces Schres. and Zoysia japonica Steud.

Domestic sewage was treated with subsurface wastewater infiltration system covered by two different turf grass, namely, Festuca aroundinaces Schres and Zoysiajaponica Steud to study the removal effects of N and P. The result show that TN concentration of Festuca around inaces Schres varied from 46.8 to 52.7 g·kg^-1 and it was significantly higher than that of Zoysia japonica Steud. The TP concentration of Festuca aroundinaces Schres varied from 4.64 to 5.89 g· kg^-1 and there were no prominent differences between the two turf grass. The average nitrogen amount taken out by Festuca aroundinaces Schres are 0.237g·m^-2·d^-1, 0.180 g·m^-2·d^-1 and 0.118 g·m^-2·d^-1 in different month which are significantly higher than that of Zoysia japonica Steud. The nitrogen removal rates of Festuca aroundinaces Schres clippings are 21.4%, 13.1% and 11.8% in September, November and December respectively. The average phosphorous amount taken out by Festuca aroundinaces Schres are 23.4 mg · m^-2 · d^-1, 15.1 mg · m^-2 · d^-1 and 13.8mg·m^-2·d^-1 in different month which are significantly higher than that of Zoysia japonica Steud. The phosphorous removal rates of Festuca aroundinaces Schres clippings are 30.2%,24.4% and 22.4% in September, October and November respectively.