16 th Kawasaki International Eco-Business Forum

Water environmental preservation
and recycling by ZLD system

Toshiba Infrastructure Systems & Solutions Corporation
November 13, 2019
© 2019 Toshiba Infrastructure Systems & Solutions Corporation

Industrial water flow
GroundwaterRiver waterLake water

The need for recycled water
Tap water①Shortage of water resources②Tightening laws and regulations③CSR④Effective use of resources
etc.

Industrial water

Water supply

Recycled water
ETP

Factory(Effluent
Treatment Plant)

Treated water

Waste water
SewerageRiverLakeSea© 2019 Toshiba Infrastructure Systems & Solutions Corporation2

What is the ZLD system

ZLD ＝ Zero Liquid Discharge
Wastewater treatment system with zero liquid waste
RecycledwaterFactory
WastewaterETP

TreatedwaterZLD SystemRecycle
SystemRejectwater Concentration system

Industrialwaste

NoLiquid×© 2019 Toshiba Infrastructure Systems & Solutions Corporation3

Where the ZLD system is used
Introduction background・Regulation of nitrogen and phosphorus (Jiangsu)
・Mandatory ZLD (coal / chemical)
・Setting of water recovery rate (Zhejiang)North America

India
China

・Mandatory ZLD for Power plants（USA)・Use of surface water in oil sand extraction（Canada）
・Regulation roadmap for wastewater recycling (Gujarat)
・Mandatory evaporator at textile factory (Tamil Nadu)
・Tightening drainage regulations (Maharashtra)

Potential area

© 2019 Toshiba Infrastructure Systems & Solutions Corporation4

ZLD for India(Area we are targeting in India)

In India, river pollution is a serious social problem.
So ZLD system is mandatory in some high pollution
industry.

Safe water to the world
Water environmental
preservation

Reference March to Sustainability Zero Liquid Discharge Market Opportunities and Outlook for India by 2020

© 2019 Toshiba Infrastructure Systems & Solutions Corporation

5

Solution to technical problem of ZLD system
Recycle System

ProblemTreatedwater

Rejectwater

pH : ~7①Scale （CaCO3,SiO2)②Bio-fouling（Bacteria, Organic, Colloid)

Solution
Step１

Step２

Step３

Ion
Exchanger

Degasser

Alkalization

Treatedwater

RecycleSystem

pH8.5~

Remove cations(Ca,etc)

Remove HCO3-

Next page© 2019 Toshiba Infrastructure Systems & Solutions Corporation

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Why adjust pH （Alkalization）
Causative substance offouling and scaling

Running at high pH

SiO2

Improved solubility (Fig. 1)

Organic

Adhesion prevention
by saponification

Bacteria

InactiveColloid

Zeta potential rise

Solubility(％)

Fig.1
pH dependence of
SiO2 solubility(at: 25 ℃)

Solubility improved byabout 3.5 times© 2019 Toshiba Infrastructure Systems & Solutions Corporation

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Our case study in India
Rejectwaterconductivity ( S / cm)

We have already installed our ZLD
system at the following 3 locations.
Here is one of the case.

Treatedwater

Rejectwater

Recycled
water

Treatedwater

Responsibility to makeWater recycling

Water recovery rate (%)

Working days

Recovery rate byconventional
Recycled system

Our system
Average95%

Working days
© 2019 Toshiba Infrastructure Systems & Solutions Corporation

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For further environmental preservation promotionOur ZLD system not only protects
the water environment, but also reduces
the amount of energy used by improving
the water recovery rate.

％
120

CO2 emissions comparison

100806040

We will aim to reduce reject waterfor further energy reduction.

RecycleSystemClimate change issue
Saving energy

200
GENERAL ZLDOUR ZLD

Concentration systemRejectwater５％
EvaporatorDryer© 2019 Toshiba Infrastructure Systems & Solutions Corporation9Epilogue© 2019 Toshiba Infrastructure Systems & Solutions Corporation10