Development of Dissolved N2O Suppression Technology for Partial Nitritation - Anammox Process

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K18044
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 64020:Environmental load reduction and remediation-related
• Research Institution: Hiroshima University
• Principal Investigator: Suenaga Toshikazu 広島大学, 先進理工系科学研究科(工), 助教 (80828377)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: 亜酸化窒素 / ガス透過膜 / 窒素除去 / 温室効果ガス / 排水処理

Outline of Final Research Achievements

As a technology to reduce N2O emission from wastewater treatment processes, this study aims to investigate the application of gas permeable membranes in three stages: suppression of N2O formation in the partial nitritation step, recovery of dissolved-N2O from the anammox step, and degradation of recovered N2O, and to evaluate their effectiveness. The N2O reduction was confirmed by installing the gas permeable membrane into the partial nitritation tank. In addition, the N2O recovery tank was examined in the absence of microorganisms, and the migration of dissolved N2O to the recovery gas side was confirmed. The application of N2O-reducing bacteria to decompose the recovered gas was also examined.

Free Research Field

環境化学工学, 環境微生物学

Academic Significance and Societal Importance of the Research Achievements

N2Oは強力な温室効果ガスとして知られ、特に窒素分が大量に流入する排水処理プロセスからの放出とその抑制技術は注目されている。一般的には好気槽の曝気によりガス態として放出されると考えられているが、プロセスによっては溶存態として放流水と供に系外に放出される可能性があり、それも最終的には大気中に拡散すると考えられる。未だ有効な解決策が確立していない放流水等に含まれる溶存態 N2O の放出抑制技術の一つとしての本技術の提案と検討は学術的・社会的な意義があると考える。