Isotopomer Analysis of Production and Consumption Mechanisms of N2O and CH4 in an Advanced Wastewater Treatment System

详细信息    查看全文

• 作者：Sakae Toyoda ; Yuuri Suzuki ; Shohei Hattori ; Keita Yamada ; Ayako Fujii ; Naohiro Yoshida ; Rina Kouno ; Kouki Murayama ; Hiroshi Shiomi
• 刊名：Environmental Science & Technology
• 出版年：2011
• 出版时间：February 1, 2011
• 年：2011
• 卷：45
• 期：3
• 页码：917-922
• 全文大小：274K
• 年卷期：v.45,no.3(February 1, 2011)
• ISSN：1520-5851

文摘

Wastewater treatment processes are believed to be anthropogenic sources of nitrous oxide (N₂O) and methane (CH₄). However, few studies have examined the mechanisms and controlling factors in production of these greenhouse gases in complex bacterial systems. To elucidate production and consumption mechanisms of N₂O and CH₄ in microbial consortia during wastewater treatment and to characterize human waste sources, we measured their concentrations and isotopomer ratios (elemental isotope ratios and site-specific N isotope ratios in asymmetric molecules of NNO) in water and gas samples collected by an advanced treatment system in Tokyo. Although the estimated emissions of N₂O and CH₄ from the system were found to be lower than those from the typical treatment systems reported before, water in biological reaction tanks was supersaturated with both gases. The concentration of N₂O, produced mainly by nitrifier-denitrification as indicated by isotopomer ratios, was highest in the oxic tank (ca. 4000% saturation). The dissolved CH₄ concentration was highest in in-flow water (ca. 3000% saturation). It decreased gradually during treatment. Its carbon isotope ratio indicated that the decrease resulted from bacterial CH₄ oxidation and that microbial CH₄ production can occur in anaerobic and settling tanks.