Osaka City Waterworks Bureau Water Purification Technology R&D Program was launched in 2001 as a practical mechanism to systematically categorize research themes for solutions of water purification issues ranging from imminent priorities to long-term goals based on an understanding of the current state of purified water quality and future tasks to be addressed by the Bureau. The Program also aims to develop a platform to continue to pursue these research themes at our Purification Plants and Water Examination Laboratories, and reports results of such research regularly both internally and externally.

Publication of Research Results

Research results are examined and assessed by the Purified Water Quality Research Committee, compiled at certain intervals every year, and reported at internal technical meetings and through an internal water service journal. They are also presented publicly at national and regional research meetings of the Japan Water Works Association and its Kansai branch and at conferences of international organizations such as the International Water Association and the International Ozone Association, as well as through publicly available water service-related journals. Thus Osaka City is active in offering information on its water purification technologies both internally and externally while collecting information about state-of-the-art technologies.

Research Flow

Research projects to be undertaken in this program are roughly divided into six groups by theme. Each year, short-term and mid- and long-term goals are set for each research project and research plans are drawn up and implemented.

Research System

Water purification technology research structure at the Osaka City Waterworks Bureau

1. Evaluation of ordinary water purification system for functional enhancement

(1) Coagulation-sedimentation process

• Promotion of coagulation sedimentation treatment
• Development and introduction of new solid-liquid separation technology following renewal of coagulo-sedimentation basins
• Reduction of residual aluminum
• Prevention of harmful organisms from growing in coagulo-sedimentation basins
• Enhancement of the ability to remove sludge in coagulo-sedimentation basins

(2) Rapid sand filtration process

• Management of rapid sand filtration tank after introduction of advanced water treatment system
• Reinforcement of turbidity control in rapid sand filter
• Prevention of algae from interfering filtration process
• Introduction of new technology to rapid filtration process

2. Evaluation of advanced water treatment system for functional enhancement

(1) Ozone process

• Optimization of ozone injection control
• Promotion of ozonation

(2) Granular activated carbon process

• Renewal of granular activated carbon
• Management of granular activated carbon adsorption filters
• Enhancement of quality of granular activated carbon

3. Evaluation of the ability to treat non-regulated substances

(1) Ultratrace chemical substances

• Endocrine disruptors
• Revision of water quality standards
• Disinfection byproducts

(2) Organisms and microorganisms

• Infectious microorganisms
• Odor producing organisms

4. Evaluation on optimization of in-pipe water quality control

(1) Residual chlorine control

• Residual chlorine control in purification system
• Residual chlorine control in distribution system

(2) In-pipe water quality control

• Microorganisms
• Disinfection byproducts

5. Risk evaluation and management of total purification system

(1) Abnormality of raw water quality

• Wider deployment of device for monitoring harmful substances in raw water, enhancing its functions, and introduction of new technologies to it
• Development of system for monitoring raw water quality

(2) Abnormality of purified water quality

• Prevention of incidents that can adversely affect water quality in purification process
• Risk evaluation and management of purification system

6. Evaluation of wastewater treatment system in purification plants for functional enhancement

(1) Sludge treatment system

• Facilitation of sludge settling process
• Evaluation of sludge properties following the introduction of a chemical-free filter press dehydrator

(2) Wastewater treatment and water distribution system

• Wastewater quality at purification plant
• Wastewater and returned water treatment at purification plant

[Page Osaka City Waterworks Bureau Water Purification Technology R&D Program under Technical Information under Guide to Waterworks on the Osaka City Waterworks Bureau Website ends here.]