title: [Nitrification and denitrification in the integrated vertical flow constructed wetlands].
abstract: Nitrification and denitrification in the different layers of the integrated vertical flow constructed wetlands (IVCW) are studied. The results show the constants rate of nitrification and denitrification in the strata of IVCW were 0.01 - 6.35microg x (gxd)-1 and 3.37 - 4.19microg x (gxd)-1 respectively. The most probable number (MPN) method are employed to determine the number and distribution of nitrifying and denitrifying bacteria in the strata of the system. The results show that the numbers of nitrifying and denitrifying bacteria were 7.5 x 10(3) - 1.1 x 10(5) MPN x g(-1) and 7.5 x 10(6) - 1.1 x 10 MPN x g(-1) respectively. The positive correlation between bacteria and their action was obvious (r = 0.9661, p < 0.001, r = 0.7722, p < 0.025). It is also observed that the number of nitrifying bacteria and nitrification rate was decreased along the direction of the water in the IVCW, while denitrifying bacteria and denitrification rate was increased. And there was the significant negative correlation between nitrification and denitrification rate(r = -0.9776, p < 0.001).
authors.affiliation: State Key Lab of Fresh Water Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Feng
authors.initials: F
authors.lastname: He
authors.forename: Zhen-bin
authors.initials: ZB
authors.lastname: Wu
authors.forename: Jing
authors.initials: J
authors.lastname: Tao
authors.forename: Shui-ping
authors.initials: SP
authors.lastname: Cheng
authors.forename: Gui-ping
authors.initials: GP
authors.lastname: Fu
mesh_terms: D001673:Biodegradation, Environmental; D009566:Nitrates / Q000737:chemistry*; D009576:Nitrobacter / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D012621:Seasons; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
chemical_list: D009566:Nitrates; D009584:Nitrogen