Research by Divisions

Water Quality Control Technologies and Materials Development Water System Management International Water Environment

Research by Corporate Sponsored Research Program

International Wastewater-based Epidemiology Program

Water Quality Control Technologies and Materials Development

(1) Efficient Removal of Viruses and Harmful Substances from Water Using Nanostructured Liquid-Crystalline Polymer Membranes

Access to safe water free of viruses and harmful substances is one of the most important issues worldwide. We are developing nanostructured liquid-crystalline membranes to efficiently remove viruses and other harmful substances from water. These self-organized porous polymer membranes with channels of uniform pore size at the sub-nano or nanometer level have shown to be useful for removal of viruses from water.

Photo: A water treatment membrane that purifies water by utilizing the property that liquid crystal molecules have an ordered structure

(2) Toward an Appropriate Waterborne Virus Risk Management

We aim to establish the microbiological safety in the area of water supply, water environment, wastewater treatment, etc. In order to maintain virological safety in water supply, we developed virus concentration methods and enabled to monitor the virus reduction in real water treatment plants. We are also trying to propose new virus indicators for recreational water and to develop an appropriate risk management system in potable water reuse.

Image: Evaluation of envelope virus enrichment method / Detection of new coronavirus (click to enlarge)

(3) Safe Water Supply System Using Membrane Filtation

Membrane filtration is widely used in water purification, seawater desalination, wasterwater reuse, and household water purifiers. On the other hand, safety issues of treated water such as the leakage of pathogenic microorganisms due to deterioration caused by long-term use are becoming apparent. We will elucidate the mechanisms behind the change in the removal performance due to deterioration of membranes using structural analysis and Multiphysics simulations. Furthermore, we will develop a new safety monitoring system for achieving a safe water supply with membrane filtration.

Photo: Membrane modules at a water purification plant

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Water System Management

(1) Management of Organic Matter in the Water Environment

A wide variety of organic matter is discharged from daily life and industry and is present in the aquatic environment along with natural organic matter. Some of them are hazardous to human health and aquatic organisms, transformed to hazardous disinfection by-products, and cause water treatment problems. We are conducting research to monitor a wide range of organic pollutants, including unregulated substances, by using high-resolution mass spectrometry to understand organic matter at the molecular species level, and to identify solutions to various problems.

Photo: Survey of unregulated substances in a river basin

(2) Microbial Control in Water Use and Treatment

Microorganisms generally use organic matter to multiply, and many water treatment technologies apply microbial decomposition of substances. However, neither the composition of organic matter in the water nor the composition of microorganisms is well understood in tap water, river water and wastewater, and thus microbial growth control in such environment and biological treatment technologies is often based on conceptual understanding. Our research aims to advance water treatment and water quality control by deepening understanding microbial growth from both chemical and biological perspectives.

Photo: High-resolution mass spectrometer for understanding organic matter at the molecular species level

(3) Advancement of Urban Flood Risk Management

As the frequency of torrential rainfall increases, development of smart urban flood control is required. Therefore, we have been developing next-generation urban flood prediction systems that utilize advanced technologies such as high-resolution radar rainfall observation and real-time sensing of water levels in drainage pipes using manhole IoT. We have conducted research on maximized utilization of inundation countermeasure facilities based on highly accurate flood prediction information, evacuation behavior guidance and inundation prevention plans for damage reduction.

Image: A new urban inundation model that comprehensively analyzes water levels in river and drainage systems in the Tsurumi River lowland

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International Water Environment

(1) Improvement of Urban Water Governance and Water Inequality in Asian Developing Countries

In rapidly growing Asian cities, water shortages are a serious problem influencing public health, social life, and urban economy. Due to the lack of water governance in these cities, unequal distribution of piped water has become a common practice. This research aims to delineate the current problems of water inequality using the Water Inequality Index, and proposes means to establish urban water governance.

Graph: Water supply frequency and Duration in Kathmandu, Nepal (click to enlarge)

(2) Water Engineering and Utility Management: Future Leaders Training Program

In many Asian cities, the water demands have surpassed the supply capacity due to population growth and economic development. To alleviate water shortages, it is necessary to establish laws and regulations on water supply, and develop human resources. In this program, graduate students from Asian countries learn hands-on approaches to solve current problems in water supply engineering and management.

Photo: Seminar at water utility in Viang Chan, Lao PDR

(3) Development of Decentralized Wastewater Treatment System for Implementation in Asian Developing Countries

In developing countries in the Asian region, the introduction of domestic wastewater treatment technologies has been delayed because of economic constraints. Reducing the energy and improving the effluent water quality of the treatment system promotes the dissemination of technology. Therefore, we are conducting research on the development of an energy-saving wastewater treatment system and on-site performance evaluation.

Photo: Wastewater treatment pilot scale plant placed in the apartment in Bangkok, Thailand

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International Wastewater-based Epidemiology
(Corporate Sponsored Research Program)

Wastewater-based epidemiology (WBE) utilizes the features of sewage infrastructure, where pathogens like viruses discharged from infected individuals accumulate in wastewater treatment plants. WBE provides a potent avenue for gathering public health data, facilitating early detection of disease outbreaks and comprehension of infection trends. Since its establishment in March 2024, the International Wastewater-based Epidemiology Program has been pioneering in the field of "wastewater-based epidemiology" and aiming to contribute to the establishment of resilient societies against infectious diseases through the implementation of WBE both domestically and internationally.

Photo: Collecting samples at a wastewater treatment plant