Lingling Zhang1, Jing Zhao1, Naxin Cui1, Yanran Dai1, Lingwei Kong1, Juan Wu1, Shuiping Cheng2. 1. Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, 1239 Siping Road, Shanghai, 200092, China. 2. Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, 1239 Siping Road, Shanghai, 200092, China. shpcheng@tongji.edu.cn.
Abstract
Floating treatment wetlands (FTWs) and biofilm carriers are widely used in water purification. The objective of the present work was to explore whether and to what extent an FTW integrated with plants and biofilm carriers (FTW-I) could enhance the nutrient removal efficiency. Significantly higher removal rates of ammonia nitrogen (85.2 %), total phosphorus (82.7 %), and orthophosphate (82.5 %) were observed in the FTW-I treatment relative to the FTW with plants (FTW-P; 80.0, 78.5, and 77.6 %, respectively) and the FTW with biofilm carriers (FTW-B; 56.7, 12.9, and 13.4 %, respectively) (p < 0.05). The mass balance results indicated that plant uptake was the main pathway for N and P removal (accounting for 58.1 and 91.4 %, respectively) in FTW-I, in which only 1.2 % of the N and 5.7 % of the P was deposited on the bottom of the tank. In addition, the plants translocated 43.9 and 80.2 % of the N and P in the water and 83.5 and 88.3 % of the absorbed N and P, respectively, into their aboveground tissues. The combination of an FTW and biofilm carriers can improve the efficiency of water purification, and nutrients can be rapidly removed from the system by harvesting the aboveground plant tissues.
Floating treatment wetlands (FTWs) and biofilm carriers are widely used in waterpurification. The objective of the present work was to expn>lore whether and to what extent an FTW integrated with plants and biofilm carriers (FTW-I) could enhance the nutrient removal efficiency. Significantly higher removal rates of n>an class="Chemical">ammonianitrogen (85.2 %), total phosphorus (82.7 %), and orthophosphate (82.5 %) were observed in the FTW-I treatment relative to the FTW with plants (FTW-P; 80.0, 78.5, and 77.6 %, respectively) and the FTW with biofilm carriers (FTW-B; 56.7, 12.9, and 13.4 %, respectively) (p < 0.05). The mass balance results indicated that plant uptake was the main pathway for N and P removal (accounting for 58.1 and 91.4 %, respectively) in FTW-I, in which only 1.2 % of the N and 5.7 % of the P was deposited on the bottom of the tank. In addition, the plants translocated 43.9 and 80.2 % of the N and P in the water and 83.5 and 88.3 % of the absorbed N and P, respectively, into their aboveground tissues. The combination of an FTW and biofilm carriers can improve the efficiency of water purification, and nutrients can be rapidly removed from the system by harvesting the aboveground plant tissues.
Authors: Fei Zhong; Wei Liang; Tao Yu; Shui P Cheng; Feng He; Zhen B Wu Journal: J Environ Sci Health A Tox Hazard Subst Environ Eng Date: 2011 Impact factor: 2.269