人工湿地中植物生长特性及其对TN和TP的吸收

构建了潜流水平芦苇湿地处理富营养化污水，在近2年的研究中考察了芦苇的生长规律、 芦苇不同器官对TN和TP的吸收及季节变化，评价了植物吸收对湿地TN和TP的去除作用.结果表明，2个生长年内芦苇的生长规律不同，受第1年芦苇移植的影响，芦苇生长周期滞后，导致植物立枯生物量与活体生物量比例在2年中相同月差异很大.第2年芦苇地上生物量是第1年的3.9倍.芦苇组织中TN和TP含量遵循新鲜叶>成年根>新鲜茎的规律.新鲜植物组织中TN和TP含量变化相对不大，当植物枯萎时地上组织TN和TP含量明显下降.根中TN和TP含量在全年中基本维持稳定.植物净吸收随植物生长情况而改变，按全年衡算，当湿地进水TN和TP负荷分别为61.39和7.39 g/(m2·a)时，植物地上生物量吸收TN和TP分别占湿地TN和TP总去除量的46.0%和26.8%，植物吸收仍起到重要作用. 

Plant Growth Characteristics and Nutrient Uptake from Eutrophic Water in Constructed Wetlands

Subsurface horizontal flow constructed wetlands (CWs) planted Phragmites australiswere developed to treat eutrophic water for two years. Plant growth characteristics, nutrient uptake of different organs and seasonal variation, and the attribution of plant uptake were assessed. The results showed that the plant growth characteristics were different during the two growth years. In the first year, reed growth was postponed due to transplant, as led to differences of ratio of standing dead biomass and live biomass in the same month between the two years. Aboveground biomass of reed in the second year was about 3.9 times of that in the first year. TN and TP distribution in Phragmites australis organs can be summarised as follow: fresh leaves>grown roots>fresh stems. TN and TP contents were relatively steady in fresh organs. However, the nutrient content of aboveground biomass decreased dramatically when organs were in course of senescent. The nutrient content in root was relatively steady during the entire year. The net nutrient uptake of plant varied with plant growth. Based on nutrient balance in an entire year, 46.0% of TN and 26.8% of TP were uptaken by aboveground biomass whenthe influent TN and TP loadings were 61.39 and 7.39 g/(m²·a). Plant uptake was an important pathway for nutrient removal in the constructed wetland for treating eutrophic water.