title: [Purification of ammonia-type eutrophic waterbody in surface flow constructed wetland at a low temperature].
abstract: Denitrification in three floating-plant systems, including two subspecies of hyacinth and duckweed, and foamy board system were investigated by batch cultivation at a low water temperature of 6.8 degrees C to 7.2 deggres C. Effect of initial COD on the system at a water temperature of 6.4 degrees C to 11.2 degrees C was also discussed. The results were obtained as follows: DO was one of the important factors, NH4+ -N removals in aerobic condition were 61%-88% in overall period. NH4 -N removal in plant systems was higher than that in the foamy board and control systems while differences of TN and COD removals among plant system, foamy board system and control system were determined by the floating-plant type. The increase of initial COD concentration, followed by the decrease of DO from >4 mg/L to 0 mg/L, resulted in an obvious improvement of NO; -N removal. However, it had a less effect on other water quality norms such as COD, TN and NH4+ -N.
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Shao-kui
authors.initials: SK
authors.lastname: Zheng
authors.forename: Yan-yan
authors.initials: YY
authors.lastname: Zhang
authors.forename: Zhi-feng
authors.initials: ZF
authors.lastname: Yang
authors.forename: Jia-gang
authors.initials: JG
authors.lastname: Liu
mesh_terms: D001673:Biodegradation, Environmental; D003080:Cold Temperature; D031806:Eichhornia / Q000378:metabolism; D005068:Eutrophication; D010944:Plants / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification / Q000378:metabolism*; D014873:Water Pollutants / Q000378:metabolism*; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
chemical_list: D000644:Quaternary Ammonium Compounds; D014873:Water Pollutants