Simulation of Calamagrostis angustifolia Wetland's Purification for Phosphorus in Sewage

Calamagrostis angustifolia wetland was chosen to simulate its purification process of phosphorus by inputting phosphoric sewage artificially in the Sanjiang Plain from May to September 2008.The results showed that Calamagrostis angustifolia wetland's purification efficiency for orthophosphate in sewage was high with the average purification rate 85.26%;plant growth phase had significant influence on its purification efficiency for orthophosphate in sewage(n=60,p0.05);from Calamagrostis angustifolia's slow growth phase to senescence phase(from July 8 to September 30),its purification rate for orthophosphate in sewage reduced gradually;its purification efficiency for organophosphorus in sewage was low with the average purification rate 11.64%;plant growth phase had significant influence on its purification efficiency for organophosphorus in sewage(n=60,p0.01);from Calamagrostis angustifolia's slow growth phase to senescence phase,its purification rate for organophosphorus reduced gradually.When phosphorus input concentration increased from 5 mg/L to10 mg/L,the increase of phosphorus input concentration had unobvious influence on wetland's purification efficiency for orthophosphate in sewage while it had significant(n=60,p0.01) influence on the purification efficiency for organophosphorus in sewage and the influence varied with plant growth stages.During Calamagrostis angustifolia's rapid growth phase(from June 10 to July 7),when phosphorus input concentration increased from 10 mg/L to 20 mg/L,wetland's purification efficiency for orthophosphate in sewage significantly(n=24,p0.001) decreased while the purification efficiency for organophosphorus in sewage significantly(n=24,p0.05) enhanced.