摘要
Plenty ofinoganic nitrogen in wastewatercan cause the eutrophication in water bodies, so it is an impor-tant task to remove nitrogen. Purification rolewas realized by absortion, filtration,depositon,evaporation,nitrifica-tion annd denitrification of microbes. Although the studies of Phragmites austrilis bed in the constructed wetland arepopular, the purification performances of constructed wetland filled by saline-alkalisoit substrate are lessreported. Inthe paper, the purification efficiency of nitrogen with Phragmites austrilis bed in the constructed wetland filled bysaline-alkali soil substrate was discussed through a simulation study. Results to date indicated that the first order plugflow model was adequate to describe the nitrogen removal. The experiment showed that the diminishing concentrationof TN, N02-N, N03-N, NH4-N were closely related to hydrological retention time (HRT),the correlation coefficientwas R2=0.98499,R2=0.9911,R2=0.89407 and R2= 0.95459,respectively. According to the data,themostsuitable hydrological retention time (HRT) for this kind of constructed wetland should be determined to 4 days. In ad-dition, the experiment showed the purification efficiency of nitrogen has very broad range and drastic vibration,TN(17%-79%), NO2-N (33%-98%),NO3-N(13%-93%),NH4-N (28%-64%). The study will promote wet-land's design and operation procedures in large saline-alkaline soil areas.