Study on comprehensive evaluation and control of algal-derived disinfection byproducts in water supply systems

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01470
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 22060:Environmental systems for civil engineering-related
• Research Institution: National Institute of Public Health
• Principal Investigator: Kosaka Koji 国立保健医療科学院, その他部局等, 上席主任研究官 (60370946)
• Co-Investigator(Kenkyū-buntansha): 浅田 安廣 国立保健医療科学院, その他部局等, 主任研究官 (60610524) ; 越後 信哉 京都大学, 工学研究科, 准教授 (70359777) ; 多田 悠人 京都大学, 地球環境学堂, 助教 (70943611)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 消毒副生成物 / 藻類由来有機物 / ラフィド藻類 / 塩素処理 / リスク管理

Outline of Final Research Achievements

In this study, formation potentials of disinfection byproducts (i.e., trihalomethane, haloacetic acid, haloacetonitrile, and halaldehyde) of algal organic matter were evaluated for 23 strains in five algae groups (17 NIES strains and 6 isolated strains from raw water). The formation potentials were different among the algae groups. It was estimated that the trichloroacetic acid (TCAA) precursors of Raphidophyceae (NIES-1380) were mostly present in the high molecular weight fraction and that the TCAA precursors were phenolic glycosides. It was shown that coagulation-precipitation process was the most effective process for removal of TCAA precursors from this strain, that powdered activated carbon alone was low removal process, but the removability was improved by the combination with prechlorination, and that ozonation was also an effective removal process.

Free Research Field

水道工学

Academic Significance and Societal Importance of the Research Achievements

藻類は、消毒副生成物の前駆物質の一種であることが知られているが、藻類の種類、消毒副生成物の種類は多種にわたる。本研究の成果は、水源に存在する藻類のうち、どの藻類が消毒副生成物前駆物質として重要であるか、監視、対処すべきであるか明らかになるため、水質管理上非常に有用である。また、藻類由来有機物について、精製し、各種機器分析により消毒副生成物前駆物質の特性解析を行ったが、一連の手順は、他の天然有機物由来の消毒副生成物前駆物質の評価、藻類由来有機物の他の研究分野での評価等、幅広く応用可能である。