120 June PURO: reverse osmosis in a well Department of Water Management Section Sanitary engineering Bas Heijman

2 Content Introduction reverse osmosis Brackish water: sustainable source for drinking water Energy aspect of reverse osmosis Is infiltration of concentrate sustainable? Conclusions Other research into sustainable drinking water production

3 Introduction reverse osmosis

4 Content Introduction reverse osmosis Brackish water: sustainable source for drinking water Energy aspect of reverse osmosis Is infiltration of concentrate sustainable? Conclusions Other research into sustainable drinking water production

5 Brackish water: sustainable source for drinking water

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7 Micropollutants Water > 100 years in sub surface

8 Brackish water: sustainable source for drinking water

9 Option 1: discharge to channel Option 2: discharge to sea Option 3: infiltrate in the subsurface 1 2 3

10 Brackish water: sustainable source for drinking water RO submerged in a well Hydrostatic pressure about 7 bar No feed pump needed Cross flow pump: about 1 bar Permeate pump: about 7 bar Extraction brackish water above RO Infiltration concentrate (2x) beneath RO

11 Energy aspect of reverse osmosis Feed 50 m³/h 8 bar Permeate 25 m³/h 0 bar Concentrate 25 m³/h 7 bar>>0 bar Normal RO +8 bar Sub- murged RO +1 bar + 7 bar

12 Energy aspect of reverse osmosis PURO 40% energy savings compared to normal brackish water RO Both RO’s calculated with 50% recovery Substantial energy savings!

13 Is infiltration of concentrate sustainable?

14 Is infiltration of concentrate sustainable? In “Westland” about 1000 RO installations for farmers with infiltration of concentrate Province of South-Holland: no permits for farmers after 1013 No alternative at this moment

15 Is infiltration of concentrate sustainable? Decreasing fresh water reserve? What is the water balans? Faith of all the ions in the subsurface. Not only NaCl but also ions like As, Pb, Hg etc. How does the concept fit into regulations? Province, Netherlands, Europe How does the concept fit into future regulations?

16 Is infiltration of concentrate sustainable? At the same time: problems with salt intrusion:

17 Is infiltration of concentrate sustainable?

18 Conclusions Brackish water is a sustainable source for drinking water because of the absence of micro-pollutants PURO: 40% less energy consumption compared to conventional brackish water RO Concentrate infiltration is necessary within the PURO concept Concerns of concentrate infiltration important research topic

19 Content Introduction reverse osmosis Brackish water sustainable source for drinking water Energy aspect of reverse osmosis Is infiltration of concentrate sustainable? Conclusions Other research into sustainable drinking water production

20 Drinking with the wind Several prototypes Seawater: pressure 60 bar Brackish water: pressure 15 bar

21 Drinking with the wind 3th windmill/RO combi Cheap drink water for people in Somaliland Drinkwater from brackish groundwater with RO Direct use of wind energy (no electricity)

22 Ceramic filter pots Desinfection Point-of-use Cheap Local production 22 factories

23 Ceramic filter Pots