1. Industrial water reuse challenges
Dr. Norbert Kreuzinger
Technische Universität Wien Institute for Water Quality and Resource Management
Karlsplatz 13/226-1
1040 Viernna – Austria
24/ ATG meeting MIlano - Kreuzinger

2. Water use in industry – the frame
Globally ~20% of water withdrawals for industry
~90% of that amount is cooling water usually returned to the natural water cycle at the point of withdrawal
Very strong link between (production) processes and water quantity & quality required
from mining
to semiconductors
24/ ATG meeting MIlano - Kreuzinger

3. Is reuse of wastewater a topic at all?
Strong tendency in industry to reduce water withdrawal and per product use of water
Paper: 700 l/t -> 7 l/t
Steel: 280 m³/t -> 14 m³/t
How:
Increase of process efficiencies
Increase of internal recycling rate
Driver: costs
Pumping of water & treatment for discharge criteria vrs. recycling for internal reuse
Water – Energy – Nexus!
24/ ATG meeting MIlano - Kreuzinger

4. Closing the loop vrs. use of reclaimed water
Quality cascade
Loop can not be cycled “forever”
~ 10 % “fresh”; unpolluted water has to be channelled in mainly due to losses in regeneration process and in the output stream to channel out material
Internal recycling - you know what you have
Quantity
Quality
Stability / constancy
Optimized technical solutions
Projectable costs
24/ ATG meeting MIlano - Kreuzinger

5. Reuse of wastewater – share of sectors
GWI (2010) GWI/PUB Water Reuse Inventory, Global Water Intelligence
24/ ATG meeting MIlano - Kreuzinger

6. Industrial reuse of wastewater
Basically, technologies are available for all applications / purposes
Where there is “no” water, even today reuse in fields with very high quality demand (e.g. semiconductors in Singapure)
Reuse of municipal wastewater today mainly for
Petroleum Production and Refining
Mining and Metals
Power
Manufacturing / process water
Chemicals
Cooling
24/ ATG meeting MIlano - Kreuzinger

7. Industrial reuse of wastewater
Potential
Cooling Water
Once-Through Cooling Water Systems
Recirculating Evaporative Cooling Water Systems
Boiler Make-up Water
Industrial Process Water
Pulp and Paper Industry
Chemical Industry
Textile Industry
Petroleum and Coal
24/ ATG meeting MIlano - Kreuzinger

8. Industrial reuse of wastewater
Potential (cont)
process water (for example, concrete batching plants)
washdown water;
fire protection (such as sprinkler systems)
dust control/suppression
quarries and mines
Reuse of municipal wastewater for mining in US since 1940s
Open channel / closed systems
Prevention of aerosols to protect workers (exposure)
24/ ATG meeting MIlano - Kreuzinger

9. General challenges for industrial reuse
Substances in uww eg:
NH4
contribution to corrosion
nutrient for biofilm growth
PO4
precipitation with Ca; NH4; … -> scaling of pipes and pumps
Nutrient for biofilm growth
Solids
Fouling
“Salts & metals”
Corrosion
Precipitation
Pathogenic and environmental microbioloy
24/ ATG meeting MIlano - Kreuzinger

10. General challenges for industrial reuse
consequence
Protection of products, processes, machinery and workers
Targeted treatment for required quality to remove problematic substances may be high -> cost – benefit analysis
Channelling out of concentrated “brines” with “pollutants”
Addition of chemicals to prevent operational problems
Antiscaling agents
Antifouling agents
Hardness conditioners …
-> topic “micropollutants”
24/ ATG meeting MIlano - Kreuzinger

11. Quality standards and requirements
Human health in focus
Technical requirements / other quality parameters are in the core interest of the industry. They will do what is necessary to protect their investments
eg. Australia
24/ ATG meeting MIlano - Kreuzinger

12. How to motivate industry for recycling and reuse (internal & uww)
Advertising the possibility and providing a legal framework
Industry already faces consequences resulting from climate change effects on water availability and go for new permits
Link “trade offs” and deals related to permissions
Stringent discharge / effluent criteria
Higher costs for treatment needs to meet environmental requirements brings costs closer to those for internal reuse
24/ ATG meeting MIlano - Kreuzinger

13. 24/25.10.2018 - ATG meeting MIlano - Kreuzinger

14. Uww reuse from the point of a „northern“ country
Even northern countries nowadays are keen on reuse du to climate
Summer 2018
Burning forsts zB Sweden
No rain in Helsinki for 4 month
Crop and corn did not mature …
Lowest flow ever in Danube river
Cooling water for industry and energy production
Much less hydro electric power produced
“average” situation in a country < > Local situation
24/ ATG meeting MIlano - Kreuzinger

15. Example soccer fields in Austria
1 soccer field: 105 x 68 m ≈ m²
There is a standard for irrigation of soccer fields (DIN )
Depending on construction of field (draining); type of lawn, weather conditions, … irrigation is needed al least 6-10 days after the last wetening rain event
L/m² (15-25 mm) per irrigation event for m² that is 175 m³ per irrigation event
1 irrigation event corresponds to a daily flow of 2 L/s in a river !
At mm/a rainfall the irrigation demand for ~2.000 soccer fiels in Austria ≡ m³/a (≈ EGWhyd)
Kreuzinger