Elucidation of a factor affecting PHA accumulation in the sludge of a hydrogen gas supplying denitrification reactor and establishment of a control methodology

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K19990
• 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: University of Yamanashi
• Principal Investigator: Kamei Tatsuru 山梨大学, 大学院総合研究部, 助教 (80792168)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 水素ガス / 脱窒 / ポリヒドロキシアルカン酸

Outline of Final Research Achievements

We evaluated a factor affecting PHA accumulation in a hydrogen gas-supplying denitrification reactor, to develop a new technology for simultaneous PHA synthesis while in sewage treatment. Suspended sludge-type hydrogen gas supplying denitrification reactor was developed and operated in various operation conditions to check changes in nitrogen removal efficiency and sludge PHA content, and to elucidate microbial community structure and functional gene for PHA synthesis (PhaC gene) abundance. Lower nitrogen loading for sludge and a higher nitrogen removal efficiency in the reactor could be potential factor affecting PHA accumulation in the reactor. Thauera and Azoarcus were dominant bacteria in the sludge and had the PhaC gene, suggesting a contribution to denitrification and PHA synthesis. Furthermore, reactors also showed phosphors removal along with denitrification and PHA synthesis. These results can lead to new wastewater treatment technology development.

Free Research Field

環境浄化技術

Academic Significance and Societal Importance of the Research Achievements

PHAは良質なバイオガスの基質であるとともに、生分解性プラスチックの材料である。本研究成果を発展させれば、処理対象水に水素ガスを通気するという簡単なアプリケーションで、下水処理場の高度処理化やPHA生産工場化が達成できる可能性がある。大幅な改修を必要とせずに下水処理場の高機能化を達成する技術確立につながる知見であり、学術的・社会的にも意義のある成果が得られたと考えている。