Contribution to realization of sustainable and vibrant society(13) Development of water quality management and control techniques
for regional water use and aquatic ecosystem conservation
Research period: FY2016-2021
Program leader: Director of Water Environment Research Group

Research Summary(1) Develop a quick and accurate assessment strategies for basin water environments
With developedtechniques, monitoringand evaluation methods,
we aim to preserve water
usage in basins, living
environments andaquatic ecosystems

Develop assessment and monitoring techniques for water usage, the living environment and aquatic ecosystems

R&D Program

Locating sources of pollutant emissions
in the water environment

Next-generation high-speed sequencer

Investigate current impact mitigation strategies for water environments- Inﬂow from urban areas and agricultural land
→ Countermeasures against non-point source pollution- Inﬂow from wastewater treatment plants→ Controlled by improving the treatment performances

Proposing management
plans to improve thewater environmental
quality

Algal bloom occurrence

Develop a simple algae surveillance using DNA sequencing- In present conditions, specialized skills are required to identify musty odor-producing
planktons- Implement surveillance using new DNA sequencing technology(2) Develop adequate water treatment techniques
to mitigation water quality risks(3) Develop more efﬁcient and effective water quality
control strategies

Efﬁcient chemical contaminant removal and pathogenic microbe
disinfection

Investigate measures focusing on the changes in bottom layer environments
and inﬂow load

- Develop technology to remove micro pollutants (e.g. pharmaceuticals,surfactant) in treated wastewater through microbial carrier processes. In
particular use of low cost and energy conservation technologies tooptimize the process conditions- Aim to improve the inactivation and removal of pathogenic microorganisms in chlorine treated water through applications such as complex
disinfection technology

Salinity boundary control by
the fall weir

Ecosystem conservation by freshwater
retention
Ice-coverBoundary of salinity or
dissolved oxygen
Fall weir

Mixingsuppression
Oxygen dissolution equipment

Nutrients elution controlled by anaerobic
condition

anaerobic improvement by oxygen
dissolution equipment

Effective and efﬁcient operation by numerical prediction- Develop a prediction method and measures to improve anaerobic conditions such as freezing
brackish lakes and dam reservoirs- Propose measures to adapt to the impact of climate change on water environment quality

Although various improvement measures for water quality
have been implemented, serious issues are still found in waterenvironments, such as infectious diseases that influence socialactivities, ecological effect of chemical substances derived fromproducts for daily use, and occurrence of algal bloom and musty
odor in reservoirs. Therefore, new strategies for evaluation,
monitoring and management are required to respond to theseissues. In addition, it is important to apply these techniques tothe basins in an integrated manner to improve environmentalquality.
In this R&D program, in order to respond to these challenges wewill promote researches towards achieving the following 3 goals:(1)	Development of assessment and monitoring methods

18 PUBLIC WORKS RESEARCH INSTITUTE 2016

to understand the water environments of basins withaccuracy and speed.
(2)	Development of adequate water treatment technology forthe mitigation of water quality risks.
(3)	Development of water quality management focused on
the bottom layer environment and the inflow change instagnant water areas.
We aim to reflect these developments to the planning of theadministrative measures and technical standards by the nationalgovernment towards the improvement of water environmental
quality, conservation of regional water use in basins, living
environment and the aquatic ecosystem.