Contribution to realization of sustainable and vibrant society(10) Research on effective use of resources/energy focusing on
sewer facilities
Research period: FY2016-2021
Program leader: Director of Materials and Resources Research Group

Research Summary

Development of technologies for biomass energy production
Wastewater
treatment plant

Municipal
wastewater①Development of technology forhigh efﬁcient algae culture byusing the sewage treatment
water ,and for collection,
concentration, and dehydration of
those algae

Sewage sludge

Solar light

Discharge point

Sewage treated water

Solar light
CO2

Algal culture②Proposal ofwaterweed utilization as
Waterweed biomass energy at
sewage treated water
discharge point
Dehydration and crushing

Solar light

Concentrated and dehydration⑤Development of algae
culture technology using asludge treatment processwastewater

CO2

Coal alternative
fuel④Methane fermentation of
the mixture of sewage
sludge, culture algae andaquatic plants

R&D Program③Coal alternativefuel of the mixtureof sewage sludge,
culture algae andaquatic plants

BiogasDevelopment of technologies for effective use of vegetation biomass using the sewerage facilities
Conventional

Retain/incineration
FutureWastewater
treatment plantInﬂuent
wastewater

Tree felling and grass clippings derived from the river business

1) Heat supply technology to dry the sewage
treatment plant by woody biomass

Treated water
MethanegasSewage
treatment
Sludgeconcentrated

Digestion

MethaneFermenter2)Technology to improve efﬁciency for
sewage sludge and mixed anaerobic
digestion of grass clippings

There is a growing expectation for renewable energy towards
building of a recycle-oriented society. "Basic Energy Plan" that
was approved by the Cabinet in 2016, shows the promotion
policy of effective use of the sewage sludge as one of therenewable energy. The Ministry of Land, Infrastructure andTransport has set "New sewer vision" and it shows resourceintensive, energy supply base and self-reliance in the sewage
treatment plants as a medium-term goal. It includes facilitationof new technological development such as mixing process ofsewage sludge and other biomass and extraction methodsof useful algae using nutrients in the sewage. On the other
hand, for example, biomass such as mowed grass and logging
produced in rivers are required to be used without simply
disposing.

DryingSludge fertilizer,fuelDehydration

Incineration3)Technology to use logging and mowed
grass as sludge dewatering aid

Landﬁll

In particular the sewage treatment facilities are expectedto accept biomass and use as energy required for sewage
treatment.
In this program, in light of these circumstances, we develop
production methods for biomass energy and aim to achieve
highly efficient alga culture using the treated sewage andembark on the studies in advanced technologies for collection,concentration and dehydration for algae culture. We also
examine the applicability of result of mixture of algae culture/
water plants and sewage sludge to the coal alternative solid
fuel. Technology for utilization of wood chips and pellets as
dehydration agent for sewage sludge is also a part of ourresearch.

PUBLIC WORKS RESEARCH INSTITUTE 201615