Impact of photosynthesis and transpiration on nitrogen removal in constructed wetlands  

作　　者：LUO Weiguo WANG Shihe HUANG Juan YAN Lu HUANG Jun 

机构地区：[1]Department of Environmental Engineering&Science,Yangzhou University,Yangzhou 225009,China [2]Department of Municipal Engineering,Southeast University,Nanjing 210096,China [3]Department of Horticulture,Nanjing Agriculture University,Nanjing 210000,China

出　　处：《Frontiers of Environmental Science & Engineering》2007年第3期316-319,共4页环境科学与工程前沿（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(Grant No.50278016)。

摘　　要：To determine the impact of photosynthesis and transpiration on nitrogen removal in wetlands,an artificial wetland planted with reeds was constructed to treat highly concentrated domestic wastewater.Under different meteoro-logical and hydraulic conditions,the daily changes of photo-synthesis and transpiration of reeds,as well as nitrogen removal efficiency were measured.It was found that net pho-tosynthesis rate per unit leaf area was maintained on a high level(average 19.0μmol CO_(2)/(m^(2)·s))from 10:00 to 14:00 in July 2004 and reached a peak of 21.1μmol CO2/(m2·s)when Photon Flux Density was high during the day.Meanwhile,TN and NH_(4)^(+)-N removal efficiency rose to 79.6%and 89.6%,respectively-the maximum values observed in the test.Correlation coefficient analysis demonstrated a positive cor-relation among photon flux density,net photosynthetic rate,transpiration rate,and TN and NH_(4)^(+)-N removal efficiency.In contrast,there was a negative correlation between stomatal conductance and TN and NH_(4)^(+)-N removal efficiency.Results suggest that the photosynthesis and transpiration of wetland plants have a great impact on nitrogen removal efficiency of wetlands,which can be enhanced by an increase in the photo-synthesis and transpiration rate.In addition,the efficiency of water usage by reeds and nitrogen removal efficiency could be affected by the water level in wetlands;a higher level boosts nitrogen removal efficiency.

关 键 词：wetland plant PHOTOSYNTHESIS TRANSPIRATION nitrogen removal 

分 类 号：X70[环境科学与工程—环境工程]