暖季型水生植物残体分解对冬季浮床氮去除效果的影响  

Effects of Aquatic Macrophyte Residue Decomposition on Winter Nitrogen Removal in Floating Constructed Wetlands

作　　者：吕丽萍 张淼 陈琛 安树青[1] 赵德华[1] LV Liping;ZHANG Miao;CHEN Chen;AN Shuqing;ZHAO Dehua(School of Life Science,Nanjing University,Nanjing 210023,China)

机构地区：[1]南京大学生命科学学院,江苏南京210023

出　　处：《生态环境学报》2018年第11期2102-2109,共8页Ecology and Environmental Sciences

基　　金：国家水体污染控制与治理科技重大专项(2017ZX07602-002)

摘　　要：为了解决尾水湿地冬季氮去除率不足和暖季型水生植物冬季集中分解引起的二次污染问题,设计了向冬季水芹菜(Oenanthe javanica)浮床人工湿地(FCW)添加芦苇(Phragmites australis)秸秆的小试实验,研究暖季型水生植物芦苇在冬季集中分解过程中对冷季型水生植物水芹菜的生长,以及对水芹菜浮床人工湿地冬季氮去除率的影响,旨在为解决低温条件下人工湿地氮净化效果减弱以及冬季湿地植物残体的收割管理提供指导意义。结果表明,在80d试验周期内,芦苇残体分解了33.4%;与对照(CK)相比,添加芦苇秸秆处理(FCW-L)可显著提高水芹菜的叶绿素含量、总根系活力以及生物量,水芹菜地上生物量增加了97.90g·m-2,地下生物量增加了20.30g·m-2。试验周期内,碳氮比ω(C)/ω(N)平均值由CK的3.8提升至FCW-L的13.1,而NO3--N、NH4+-N和TN累计去除率由CK的26.5%、41%和27.2%分别提升至FCW-L的90%、82%和73.4%。由此可见,冬季植物残体分解可以改善尾水湿地碳氮比失衡问题,提升冷季型水生植物浮床人工湿地冬季氮去除率。因此冷、暖季型水生植物配植可以作为一种提高尾水湿地冬季氮去除能力的新方法。To solve the problems of decreasing nitrogen removal rates and secondary pollution caused by the decomposition of warm-season aquatic macrophytes during winter in tail water wetlands,pilot-scale floating constructed wetlands were designed,planted with the cold-season macrophyte Oenanthe clecumbens,with the addition of Phragmites australis litter.The influence of the concentrated decomposition of the warm-season aquatic macrophyte P.australis on the growth of O.clecumbens and the nitrogen removal rate were examined in the floating constructed wetlands.The purpose of this study was to provide guidance to enhance the nitrogen purification efficiency of constructed wetlands at low temperatures and the harvesting management of plant residues in winter wetlands.The results showed that the biomass loss was 33.4%for P.australis through the 80-day experiment.Compared to the control(CK),adding P.australis litter treatment(FCW-L)significantly increased O.clecumbens chlorophyll content,total root activity,and aboveground biomass to 97.9 g·m-2 and underground biomass to 20.3 g·m-2.In the experimental period,the average value of the carbon and nitrogen ratioω(C)/ω(N)increased from a value of 3.8 that of CK to 13.1 of FCW-L,whereas the total removal rate of NO3--N,NH4+-N,and TN increased from 26.5%,41%,and 27.2%of that of CK to 90%,82%,and 73.4%of FCW-L,respectively.Therefore,it was concluded that the decomposition of plant litter in winter could improve the imbalance ofω(C)/ω(N)in the tail water wetland,and enhance the nitrogen removal rate of the floating constructed wetland in winter.Therefore,the re-arrangement of cold and warm season aquatic plants could be an effective strategy for improving the nitrogen removal capacity of tail water wetlands in winter.

关 键 词：芦苇残体 水芹菜 碳氮比 氮去除 

分 类 号：X173[环境科学与工程—环境科学]