Denitrification coupled with methane anoxic oxidation and microbial community involved identification

Brazilian Archives of Biology and Technology

Renata Medici Frayne Cuba¹  Iolanda Cristina Duarte¹  Nora Katia Saavedra¹  Maria Bernadete Amâncio Varesche¹  Eugenio Foresti¹ 

[1] ,Universidade de São Paulo Escola de Engenharia de São Carlos Departamento de Hidráulica e SaneamentoSão Carlos SP ,Brasil

关键词: denitrification;    Methylomonas sp;    methane oxidation;   

DOI  :  10.1590/S1516-89132011000100022

来源: SciELO

【 摘 要 】

In this work, the biological denitrification associated with anoxic oxidation of methane and the microbial diversity involved were studied. Kinetic tests for nitrate (NO3-) and nitrite (NO2-) removal and methane uptake were carried out in 100 mL batch reactors incubated in a shaker (40 rpm) at 30 ºC. Denitrificant/methanotrophic biomass was taken from a laboratory scale reactor fed with synthetic nitrified substrates (40 mgN L-1 of NO3- and subsequently NO2-) and methane as carbon source. Results obtained from nitrate removal followed a first order reaction, presenting a kinetic apparent constant (kNO3)) of 0.0577±0.0057d-1. Two notable points of the denitrification rate (0.12gNO3--N g-1 AVS d-1 and 0.07gNO3--N g-1 AVS d-1) were observed in the beginning and on the seventh day of operation. When nitrite was added as an electron acceptor, denitrification rates were improved, presenting an apparent kinetic constant (kNO2) of 0.0722±0.0044d-1, a maximum denitrification rate of 0.6gNO2--N g-1AVS d-1, and minimum denitrification rate of 0.1gNO2--N g-1AVS d-1 at the beginning and end of the test, respectively. Endogenous material supporting denitrification and methane concentration dissolved in the substrate was discarded from the control experiments in the absence of methane and seed, respectively. Methylomonas sp. was identified in the reactors fed with nitrate and nitrite as well as uncultured bacterium.

【 授权许可】

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