News Release

METAWATER signs a basic business agreement for OEM supply of “upflow filtration system using floating filter media” with five water treatment-related companies
To contribute to controlling sewage outflowing from combined sewer systems to rivers and sea during heavy rainfall

METAWATER Co., Ltd. (Headquarters: Tokyo, Japan; President: Tomoyasu Kida; hereinafter referred as “METAWATER”) is pleased to announce the signing of a basic business agreement (hereinafter referred to as the "Agreement") for OEM supply of its upflow filtration system using floating filter media (hereinafter referred as the “System”) with KUBOTA Corporation (Headquarters: Osaka, Japan; President: Masatoshi Kimata), Suido Kiko Kaisha, Ltd. (Headquarters: Tokyo, Japan; President: Masanobu Kadokawa), Swing Corporation (Headquarters: Tokyo, Japan; President: Shigeo Mizutani), Sumitomo Heavy Industries Environment Co., Ltd. (Headquarters: Tokyo, Japan; President: Kyoichi Manabe), and TSUKISHIMA KIKAI Co., Ltd. (Headquarters: Tokyo, Japan; President and CEO: Kazuhiko Yamada). Based on this Agreement with five companies having extensive experience in water treatment, METAWATER will facilitate the use of the System, both at home and abroad.

Overview of the System

The System is designed to facilitate the advancement of simple treatment in combined sewer systems and simple treatment of untreated sewage, contributing to the reduction of the volume of pollutants by controlling sewage that outflows in high volume from combined sewer systems to rivers and the sea during heavy rainfall. As the installation uses the existing facilities coupled with its easy operation and maintenance, the System contributes to reducing costs related to facilities construction and maintenance.
METAWATER has established the technology of the System through a series of joint research with Yokohama City and Tokyo for the improvement of combined sewer systems and with Osaka City for the effectiveness of continuous operation during dry weather. In 2005, technologies for the improvement of combined sewer systems received a technology assessment from the Sewerage Technology Development Project (SPIRIT21) by the Ministry of Land, Infrastructure, Transport and Tourism (MLIT). In 2008, METAWATER, together with the Bureau of Sewerage of the Tokyo Metropolitan Government, received the Minister of Economy, Trade and Industry Award at the 34th Outstanding Environmental Systems Awards hosted by the Japan Society of Industrial Machinery Manufacturers. In recent years, the System has been used in the “demonstration study for an energy management system using intensive solid-liquid separation technology”*1 under the Breakthrough by Dynamic Approach in Sewage High Technology Project (B-Dash project) by the MLIT and “advanced energy saving wastewater treatment process: a water treatment process equipped with Floating Sponge Filtration system, High-rate Trickling Filtration system, and Final Solid-Liquid Separation tank”*2 which received the first international technology certificate from the Japan Sewage Works Agency.

Key features

  • ・Improves combined sewer systems through reduction of BOD and overflow as well as elimination of impurities and oil balls
    BOD: Biochemical oxygen demand
  • ・Contributes to controlling the outflow of untreated sewage during wet weather and facilitating emergency restoration measures
  • ・Enables installation using the existing facilities (primary sedimentation tank, rain water settling tank)
  • ・Serves as an alternative for a primary sedimentation tank, reducing space necessary for primary treatment
  • ・Filter media cleaning while continuing filtration enables continuous operation even during prolonged rainfall
  • ・Contributes to creating energy using sludge through effective collection of crude sludge
  • ・Enables combined use with other advanced treatment (e.g. carrier method)
  • ・Enables no coagulation treatment with the use of fine filter media, eliminating operation during wet weather and contributing to reducing maintenance costs
  • ・Easy operation and management due to no need for pre-treatment screens and bottom screens to prevent outflow of filter media

Special filter media

Filter media developed using unique special materials
  • ・Unique shape that increases the filtration time
  • ・Small size of 7.5mm or less, eliminating the need for flocculant agent
  • ・Acid-resistant, alkali-resistant, and abrasion-resistant material
  • ・Material that prevents the attachment of SS (suspended solid) and oil/fat

Treatment flow

With functions to change filtration speed according to the volume of incoming raw water and automatic cleaning of clogged filter media through the detection of an increase in raw water level, the System is capable of responding to temporal changes in the quality and quantity of raw water during both wet and dry weather. Cleaning is carried out through a gravity flow system using water level differences by opening high speed backwash system at the bottom and using filtrate water stored in the upper part of the filter basin.

*1 Implemented as part of research outsourced from the National Institute for Land and Infrastructure Management, the Ministry of Land, Infrastructure, Transport and Tourism
   Operator: Research consortium of METAWATER and the Japan Sewage Works Agency
     METAWATER press release:
*2 Japan Sewage Works Agency press conference materials:
     METAWATER press release:


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