Green & Clean POSCO

W ater Treatment Management FOR Sustainable Industry

11.23

Hyo Seon Kim

Stable water supply for long term strategy

Strengthening of wastewater regulation

Increased needs for process water by expansion of steel production facility

Backgrounds

Dam Water

Ground Water

ProcessWater

Production

Process(Coke making, Steel making,

Cold Rolling etc)

1st WastewaterTreatment

(end of each process)

1st WastewaterTreatment

(end of each process)

Sewage, Rain water, Indirect Cooling Water

Treatment

Sewage, Rain water, Indirect Cooling Water

Treatment

2nd(Final) Waste-water

Treatment

2nd(Final) Waste-water

Treatment

Reuse

Reuse Reuse

Recycling

Evaporation

Discharge Discharge

Water BalanceWater Balance

Recirculation (98%)

Water Supply SystemWater Supply System

River Water

Ground water

Reused Water

MM

Mixing tank

M

Settling Basin

Sand Filter

Reservoir

Water Supply Water

Supply

Water Supply Water

Supply

* Suspended solids are removed by coagulant addition and precipitated in the settling basin.

* The treated water is transported to each process unit

Water Supply and QualityWater Supply and Quality

Pohang Works

Water supply per day (㎥ /day) 170,000

Water Use per ton of steel (㎥ /T-S)

4

Water supply

Water quality

Pohang Worls

Turbidity (NTU) < 1

Ca 40

Cl- 5

Wastewater TreatmentWastewater Treatment

Biol. Ammonia Treatment

Biol. Ammonia Treatment

A/C Adsorption A/C Adsorption

Biol. DenitrificationBiol. Denitrification

Iron & Steel Section

WWT

Iron & Steel Section

WWT

Hyungsan River

Nang River

Rolling Section

WWT

Rolling Section

WWT

1st WWT1st WWT Advanced WWT

Advanced WWT

Final WWTFinal WWTProcessProcess

WireWire

Cold RollingCold Rolling

STSSTS

ElectricElectric

PlatePlate

Hot RollingHot Rolling

Coke BETCoke BET

BFBF

FINEXFINEX

C/CC/C

Phenol, CNPhenol, CN

NH4, zinc, CNNH4, zinc, CN

NH4, SSNH4, SS

F F

SS, OilSS, Oil

Acid, Oil, MetalAcid, Oil, Metal

F, MetalF, Metal

Acid, Oil, MetalAcid, Oil, Metal

SS, OilSS, Oil

SS, OilSS, Oil

Wastewater FacilitiesWastewater Facilities

Activated carbon facilityDenitrification WWT in STSfinal WWT of Pohang

Wastewater EffluentWastewater Effluent

Quality

Pohang Works

Seongang WWT Apyeon WWT

Flowrate ( ㎥ /day) 18,000 30,000

COD (mg/L) 16 9

SS (mg/L) 7 7

* Seongang - Upstream process including BF

* Apyeon – Down process including cold rolling mill

Rain Water TreatmentRain Water Treatment

Water Way

Constructing Site

Rain Water

Collecting Basin Rain Water Treatment

Storage Pond

HyungsanRiver

Reuse

Dscharge

Reuse

Rain Water Treatment Rain Water Treatment

Quality

Usage Pohang Works

Industrial Supply Water 1,900

Road Spray 9,000

Rain water reuse

Flowrate( ㎥ /day)

COD (mg/L) SS (mg/L)

44,000 8 5

(Unit : ㎥ /day)

Sewage Treatment SystemSewage Treatment System

- Toilets, Bathrooms,- Restaurants, Laundry

ReuseRelay

Pit

RelayPit

Biological Sewage

Treatment

Biological Sewage

Treatment

Pit(Car)

Pit(Car)

SewageSources

SewageSources Pit

(Pumping)

Pit(Pumping)

* Sewage from over 600 sites containing bathroom, restaurant, laundry is collected through car and pumping into the relay pit and is transferred to the this facility.

Application of Reused WaterApplication of Reused Water

Road Spray

Mixing to Process Water

Slag QquenchingInternal Supply

Others

* We are establishing strategic plan for maximizing water reuse and minimizing discharge such as re-evaluation of water quality standards for each process, increase of recycling ratio in cooling water system, and installation of reserve osmosis and so on.