{"title":"Nitrogen removal and N2O emission in a full-scale domestic wastewater treatment plant with intermittent aeration","authors":"Yuzuru Kimochi , Yuhei Inamori , Motoyuki Mizuochi , Kai-Qin Xu , Masatoshi Matsumura","doi":"10.1016/S0922-338X(98)80114-1","DOIUrl":null,"url":null,"abstract":"<div><p>Nitrous oxide (N<sub>2</sub>O) is emitted from wastewater treatment processes. It is known as a greenhouse gas that contributes to global warming (over 200 times more per molecule than carbon dioxide) and to the destruction of the ozone layer. It is therefore of great importance to develop technology that can suppress N<sub>2</sub>O emission. The effects of an anoxic period on N<sub>2</sub>O emission and nitrogen removal were investigated in an actual domestic wastewater treatment plant. When operated with intermittent aeration, most of the N<sub>2</sub>O was emitted into the atmosphere during the aerobic period. N<sub>2</sub>O emission from the intermittent process was estimated to be 0.43–1.89 g N<sub>2</sub>O person<sup>−1</sup> year<sup>−1</sup>. Maintaining a dissolved oxygen (DO) concentration of over 0.5 mg <em>l</em><sup>−1</sup> during the aerobic period resulted in the complete conversion of the influent NH<sub>4</sub>-N to NO<sub>3</sub>-N and a 60-min anoxic period was sufficient for denitrification to be completed. The findings show that an optimum combination of aerobic and anoxic conditions and their suitable control are very important for improving nitrogen removal efficiency and controlling N<sub>2</sub>O emission.</p></div>","PeriodicalId":15696,"journal":{"name":"Journal of Fermentation and Bioengineering","volume":"86 2","pages":"Pages 202-206"},"PeriodicalIF":0.0000,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0922-338X(98)80114-1","citationCount":"185","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Fermentation and Bioengineering","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0922338X98801141","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 185
Abstract
Nitrous oxide (N2O) is emitted from wastewater treatment processes. It is known as a greenhouse gas that contributes to global warming (over 200 times more per molecule than carbon dioxide) and to the destruction of the ozone layer. It is therefore of great importance to develop technology that can suppress N2O emission. The effects of an anoxic period on N2O emission and nitrogen removal were investigated in an actual domestic wastewater treatment plant. When operated with intermittent aeration, most of the N2O was emitted into the atmosphere during the aerobic period. N2O emission from the intermittent process was estimated to be 0.43–1.89 g N2O person−1 year−1. Maintaining a dissolved oxygen (DO) concentration of over 0.5 mg l−1 during the aerobic period resulted in the complete conversion of the influent NH4-N to NO3-N and a 60-min anoxic period was sufficient for denitrification to be completed. The findings show that an optimum combination of aerobic and anoxic conditions and their suitable control are very important for improving nitrogen removal efficiency and controlling N2O emission.
一氧化二氮(N2O)是从废水处理过程中排放出来的。众所周知,它是一种温室气体,会导致全球变暖(每分子比二氧化碳多200多倍),并破坏臭氧层。因此,开发抑制N2O排放的技术具有重要意义。在实际生活污水处理厂中,研究了缺氧周期对N2O排放和氮去除的影响。间歇曝气时,大部分N2O在好氧期排放到大气中。间歇过程的N2O排放量估计为0.43-1.89 g N2O人−1年−1。在好氧期间,将溶解氧(DO)浓度维持在0.5 mg l - 1以上,可使进水NH4-N完全转化为NO3-N, 60分钟的缺氧期足以完成反硝化。结果表明,好氧和缺氧条件的最佳组合及其控制对提高脱氮效率和控制N2O排放具有重要意义。