Chlorine-consuming dissolved organic matter in a water supply system and its management for residual chlorine control

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06616
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Civil and environmental engineering
• Research Institution: Gifu University
• Principal Investigator: Yamada Toshiro 岐阜大学, 工学部, 准教授 (30335103)
• Co-Investigator(Kenkyū-buntansha): 李 富生 岐阜大学, 流域圏科学研究センター, 教授 (10332686)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 水道 / 溶存有機物 / 残留塩素 / 浄水スラッジ

Outline of Final Research Achievements

In this study, highly chlorine-consuming dissolved organic matters (DOM), which is not be found in raw water and difficult to be removed from water with a powdered activated carbon application, were found in the sludge filtrate in the return water to source water in a purification plant with a closed system.
Especially in summer when the sludge was kept in a concentration tank at high temperature under anoxic condition, the sludge filtrate could have high DOM concentration including the highly chlorine-consuming DOM, which indicates that sludge management such as sludge storage under the aerobic condition in a shorter period is required for residual chlorine control in purified water in sending pipes.

Free Research Field

水環境工学

Academic Significance and Societal Importance of the Research Achievements

浄水場内で発生した排水等を着水井に返送し，水を有効活用するクローズドシステムを採用している浄水場における，水中の溶存有機物の特徴を把握し，返送水に原水にはない有機物が含まれていることを示した。またこの有機物が塩素消費性が高く粉末活性炭吸着しにくい成分であること，発生する汚泥を嫌気雰囲気で比較的高い温度で貯留した場合に発生することなどを明らかにし，クローズドシステムを採用している浄水場において汚泥貯留における監視や管理が重要であることを指摘した。