Yang Chang-Ming, Gu Guo-Quan, Li Jian-Hua, Deng Huan-Huan
Key Laboratory of Yangtze Water Environment of MOE, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Huan Jing Ke Xue. 2008 Nov;29(11):3043-8.
Hydraulic residence time distributions (RTD) and spatial variations of N, P were studied in a small-scale horizontal subsurface-flow constructed wetlands (HSFCWs) planted with Cyperous alternifolius and Typha angustifolia respectively for purification of eutrophic aquaculture water. The results show that the residence time distribution curves of the investigated HSFCWs lie between plug-flow and completely mixed model with characteristic values (sigma2) of 0.3246 and 0.4108, respectively. Compared with Typha angustifolia, Cyperous alternifolius wetland shows fine flow pattern with characteristics of smoother RTD curve and weaker vertical mixed flow. Total nitrogen (TN) and ammonia nitrogen (NH4+-N) show stratified distributions in the two HSFCWs, especially in the front end of the wetland beds. TN in the lower layer is higher than that in the upper, while NH4+-N in the middle layer is the lowest in all the sampling layers. Total phosphorus (TP) and phosphate (PO4(3-)-P) increases with sampling depth. Differences in TP and PO4(3-)-P between the layers decrease gradually along distance. Cyperous alternifolius wetland shows better stratification distributions of N, P, as compared with Typha angustifolia, which is mainly contributed to the difference in flow patterns between the two HSFCWs. On average, concentrations of TN and TP in the rear end of the Cyperous alternifolius wetland are 19.3% and 12.5% lower, respectively, as compared to the Typha angustifolia wetland, suggesting that removal efficiencies of the Cyperous alternifolius wetland for purification of eutrophic aquaculture water is higher than those of the Typha angustifolia.
研究了分别种植风车草和狭叶香蒲的小型水平潜流人工湿地（HSFCWs）对富营养化养殖水的净化效果，分析了其水力停留时间分布（RTD）及氮、磷的空间变化。结果表明，所研究的HSFCWs的停留时间分布曲线介于活塞流和完全混合模型之间，特征值（sigma2）分别为0.3246和0.4108。与狭叶香蒲相比，风车草湿地具有较好的水流模式，其RTD曲线更平滑，垂直混合流较弱。总氮（TN）和氨氮（NH4+-N）在两个HSFCWs中呈分层分布，尤其是在湿地床的前端。下层的TN高于上层，而中层的NH4+-N在所有采样层中最低。总磷（TP）和磷酸盐（PO4(3-)-P）随采样深度增加。各层间TP和PO4(3-)-P的差异沿距离逐渐减小。与狭叶香蒲相比，风车草湿地对N、P的分层分布更好，这主要归因于两个HSFCWs水流模式的差异。平均而言，风车草湿地后端的TN和TP浓度分别比狭叶香蒲湿地低19.3%和12.5%，表明风车草湿地对富营养化养殖水的净化去除效率高于狭叶香蒲。
