Water Treatment Management FOR Sustainable Industry Green & Clean POSCO Water Treatment Management FOR Sustainable Industry 11.23 Hyo Seon Kim

Backgrounds Stable water supply for long term strategy Strengthening of wastewater regulation Increased needs for process water by expansion of steel production facility

Indirect Cooling Water Water Balance Recycling Evaporation Ground Water 1st Wastewater Treatment (end of each process) Process (Coke making, Steel making, Cold Rolling etc) Process Water Production Dam Water Reuse Recirculation (98%) Reuse Reuse Sewage, Rain water, Indirect Cooling Water Treatment 2nd(Final) Waste- water Treatment Discharge Discharge

Water Supply System Reservoir Ground water Mixing tank Settling Basin River Water Water Supply Reused Water Sand Filter * Suspended solids are removed by coagulant addition and precipitated in the settling basin. * The treated water is transported to each process unit

Water supply per day (㎥/day) Water Use per ton of steel Water Supply and Quality Water supply Pohang Works Water supply per day (㎥/day) 170,000 Water Use per ton of steel (㎥/T-S) 4 Water quality Pohang Worls Turbidity (NTU) < 1 Ca 40 Cl- 5

Wastewater Treatment Process 1st WWT Advanced WWT Final WWT Coke BET Phenol, CN Iron & Steel Section WWT A/C Adsorption NH4, zinc, CN Hyungsan River BF Biol. Ammonia Treatment FINEX NH4, SS C/C F Wire SS, Oil Rolling Section WWT Cold Rolling Acid, Oil, Metal STS F, Metal Biol. Denitrification Nang River Electric Acid, Oil, Metal Plate SS, Oil Hot Rolling SS, Oil

Wastewater Facilities final WWT of Pohang Denitrification WWT in STS Activated carbon facility

Wastewater Effluent Quality Pohang Works Seongang WWT Apyeon WWT Flowrate (㎥/day) 18,000 30,000 COD (mg/L) 16 9 SS (mg/L) 7 * Seongang - Upstream process including BF * Apyeon – Down process including cold rolling mill

Rain Water Treatment Constructing Site Storage Pond Collecting Basin Reuse Water Way Dscharge Hyungsan River Rain Water Reuse

Industrial Supply Water Rain Water Treatment Quality Flowrate (㎥/day) COD (mg/L) SS (mg/L) 44,000 8 5 Rain water reuse (Unit : ㎥/day) Usage Pohang Works Industrial Supply Water 1,900 Road Spray 9,000

Biological Sewage Treatment Sewage Treatment System Relay Pit Biological Sewage Treatment Sewage Sources Pit (Car) Pit (Pumping) Reuse - Toilets, Bathrooms, - Restaurants, Laundry * 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.

Mixing to Process Water Application of Reused Water Road Spray Mixing to Process Water Slag Qquenching Internal 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.