Environmentally friendly products

Development of environmentally friendly products

Key development themes

Themes behind the Group's research and development. Designating these as our priority issues, we aim to contribute to the global environment.

Water technologies

Renewal, operation and management of entire water treatment plant [Kawai Purification Plant, Yokohama City] Eco-friendly water treatment using natural power

Photovoltaic power generation equipment

Photovoltaic power generation panels are installed on the roof of water distribution tanks. Making effective use of natural energy leads to a reduction in power consumption of about 40% compared with the conventional system.

Filtration without power consumption by using elevation difference

Water derived from the Doshi River is led to a water distribution tank after being treated with a membrane filtration system without using a pump. Filtration without power consumption is realized by using the difference in geographical elevation from the water source to the water treatment plant.

Ozone/accelerated oxidation treatment technology
Removes substances causing moldy smells produced by algae with high efficiency

Moldy smells caused by algae pose a serious problem to water treatment plants using lakes or ponds as a water source in the vicinity of an urban area. To address this issue, ozone/accelerated oxidation treatment technology was developed.
This technology eliminates moldy smells with higher efficiency compared with the level achieved by ordinary ozone treatment, while making it possible to elongate the life of bio-active carbon through load mitigation.

Mechanism of ozone/accelerated oxidation treatment technology

By adding hydrogen peroxide, generation of hydroxyl radicals (-OH) with higher oxidizing power than ozone is promoted and the efficiency of decomposing substances causing moldy smells is enhanced. Hydrogen peroxide also works to suppress the generation of bromide ions, a byproduct of ozone treatment.

Ultraviolet treatment equipment for water treatment facilities using ultraviolet light emitting diodes (UV-LED)
World-class treatment capacity and super-long service life of about 45,000 hours

We developed the first-ever UV beam treatment equipment for water treatment plants using the world's top-class, high-power UV-LED as the light source in collaboration with Nikkiso Co., Ltd., Nikkiso Giken Co., Ltd. and Senko Riken K.K.
UV inactivation is one of the ways to control chlorine-resistant pathogenic protozoa, including Cryptosporidium, in the water treatment process. Because the use of mercury is being restricted internationally, a UV treatment system using a highly safe UV-LED is attracting public attention.
This equipment provides approximately three times longer life than UV mercury vapor lamps mainly by controlling the output of a UV-LED and optimizing irradiation. Further, it offers high safety by eliminating the use of mercury and contributes to reducing environmental burden.

Sewage technology

Incineration system using fluidized bed turbine(Simplified offering type joint research with Tokyo Bureau of Sewage)

Blowers to send air into a furnace during sludge incineration are operated with a significant amount of electric power. We developed a fluidized bed turbine incineration system adopting a turbine driven by discharged heat instead of electric power. This system can reduce power consumption by about 40% compared with the conventional system.

* This project uses Patent No. 4831309 co-owned by the Public Works Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), and SANKI Engineering Co. and TSUKISHIMA KIKAI Co.

Sludge fuel project 〈Kosai Purification Center, Shiga〉
Producing resources by making wastewater sludge into carbide

The incineration ash derived from incinerated wastewater sludge has been conventionally disposed of as industrial waste. However, this technology makes it possible to produce biomass fuel from the sludge through its carbonization treatment and use the fuel in power plants or steel works as an energy source.
Compared with a conventional incineration/melting facility, carbon emissions can be reduced by about 11,651 tons (equivalent to the emissions from approx. 3,800 general households) annually.

Sludge treatment system improvement/operation 〈Toyokawa Purification Center, Aichi〉
Power generation using wastewater sludge

Biogas (methane) generated accompanying the treatment of wastewater sludge is used for power generation. Reducing sludge treatment costs and greenhouse gas discharge is sought by making positive use of the Feed in Tariff (FIT) system stipulating mandatory purchase of regenerative energy.

Low-moisture-content sludge dehydrator
Realization of low moisture content in dehydrated sludge

Conventional one and two pack type sludge dehydration has problems related to moisture content and processing costs. The post-injection two-pack type belt press dehydrator that we developed is a dehydrator integrating the advantages of the conventional two-pack type and those of our new technology. Low moisture content is achieved with a lower dose of chemicals.

Recycling technology

Sorting equipment
Reduction in management and operation costs with high-accuracy waste sorting

When treating incombustible waste, recyclable waste such as plastics and plastic (PET) bottles are sorted for recycling to reduce environment impact. While sorting processes are basically conducted manually, the METAWATER Group's waste-sorting equipment allows high-accuracy sorting, as well as minimizing labor and associated costs.

Reduction of life cycle costs related to management and operation

Because this waste-sorting equipment can sort incombustible waste into non-combustible heavy substances, combustible light substances and fine granular substances, the workload associated with manual sorting can be minimized, and this results in a reduction in workforce and operation costs.
●Percentage of reduction in workforce for manual sorting: 10%-30%

Superb effect in rationalizing sorting of plastic containers and packages

When recycling plastic containers and packages, prohibited substances or metal must not be included. However, because this equipment will sort metals automatically into heavy substances, it is easy to find and remove them securely during manual operation.

High-accuracy sorting is possible

The waste-sorting equipment is arranged before the manual sorting process to eliminate film or sheet type combustibles that hinder manual operation. This allows for high-accuracy sorting by preventing workers from overlooking the items to be screened out during manual operation.

Mechanism of sorting