Development of the sewage treatment system to maximize resource and energy recovery

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K04412
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22060:Environmental systems for civil engineering-related
• Research Institution: Fukui University of Technology
• Principal Investigator: Takashima Masanobu 福井工業大学, 工学部, 教授 (30257498)
• Co-Investigator(Kenkyū-buntansha): 矢口 淳一 八戸工業高等専門学校, その他部局等, 教授 (80342450)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 下水 / 下水汚泥 / 嫌気性消化 / アンモニアストリッピング / リン酸吸着 / バイオガス / 窒素リン回収

Outline of Final Research Achievements

This research aimed to develop a sewage treatment system that maximizes resource and energy recovery as methane, ammonia and phosphate. For sewage, sieving and aluminum coagulation were examined, and appropriate operating conditions and issues were clarified. Regarding anaerobic digestion of sewage sludge, high-solid digestion and thermal pre-treatment enhanced organic decomposition and biogas production. Ammonia stripping and phosphate adsorption with iron hydroxide, when combined with the anaerobic digestion, made it possible to alleviate ammonia inhibition and to recover about 21% of N and about 73% of P from sewage sludge. The addition of activated carbon to the digester and ferric iron to dewatering was effective in improving microbial activity and decolorization of digested sludge liquor.

Free Research Field

土木環境システム

Academic Significance and Societal Importance of the Research Achievements

国土交通省の下水道ビジョンは、『従来の下水を排除・処理する一過性のシステムから、集めた物質等を資源・エネルギーとして活用・再生する循環型システムへと転換する必要がある』としている。下水処理ステムを資源・エネルギー回収型に転換し、有機物に窒素・リンを含めて総合的に検証するところに本研究の学術的および社会的意義がある。