Dr. Sabine Lattemann, הרצאה ביום עיון צלול 25.4.10

1. Seawater Desalination – A need for
Environmental Impact Assessment (EIA)
and Best Available Techniques (BAT)

2. Global seawater desalination capacity

3. Lattemann and Höpner (2009), primary datafrom IDA (2007). Map includes all plants that presumed online or in construction and all sites and a capacity with am3/day. > 1,000 m3/day.
Lattemann & Höpner (2009), primary data from IDA (2007). Map includes all plants that are are presumed online or in construction with all sites > 1,000 capacity

4. Ashkelon (330,000 m3/day)

5. Projected growth

6. Australian SWRO projects
Gold Coast:
133,000 m3/d
Sydney:
250,000 m3/d
Extension:
250,000 m3/d?
Perth
144,000 m3/d
Additional projects:
144,000 m3/d (2011)?
450,000 m3/d (2020)?

7. Résumé of the introduction

10. Energy demand

11. Energy use and CO2 emissions

12. Energy demand in perspective — Sydney

13. Is energy demand significant?

14. Desalination using renewable energy
no large desalination plant directly driven by RE,
only used as a compensation measure
mostly small stand-alone systems directly driven by RE:
Solar energy Wind / Tidal
Solar
still Heat (collector) Radiation (PV) Mechanical (turbine)
Non-concentrating Concentrating
- flat plate or tube design - parabolic trough / dish
for domestic purposes - flat mirrors (Fresnel)
- power tower
Electricity
MD MED MSF ED RO
TVC

15. Concentrating solar thermal collectors
Parabolic system
Trough Dish
Linear receivers Point receivers
Planar mirrors
Fresnel Tower

16. National Initiative for Solar Desalination
King Abdulaziz City for Science and Technology, Riyadh:
Initial phase (3 years):
• Energy: 10 MW produced by solar energy
• Water: 30,000 m3/d in Al Khafji
Second phase (3 years):
• building a 300,000 m3/d solar-powered desalination plant
Third phase (3 years):
• implementation of solar desalination plants
in several parts of the country

18. Spanish approach
80
75
70
65
60
55
50
45
40
35
30

19. Australian approach
Whole effluent toxicity (WET) tests

20. Whole effluent toxicity tests
SWRO Plant Species No. of species Species protection
protection used in trigger value
level WET tests (safe dilution ratio)
Gold Coast 95% * 6 species 9:1
Perth 95% * 5 species 12 : 1
Sydney 95% * 5 species 30 : 1
Olympic Dam 99%** 15 species 45 : 1
Ecosystems: * slightly to moderately disturbed
** high conservation value
0.7 psu above ambient in
300 m in 90% of time
1100 m in 99% of time

23. Desalination – a green technology?

24. Sustainable projects | green technologies
UNEP Guidance on internationally accepted
EIA for desalination BAT standards for desalination
projects (2008) plants are still missing
www.unep.org.bh/ U.S. EPA announced new
Publications/ rulemaking on drinking water
Type7.asp treatment effluents including
“facilities that discharge […]
Extensive EIA and monitoring desalination concentrates […]”
studies in progress for several
desalination projects worldwide

25. Conclusions
Resource-intensive process with significant impacts
need for project- and site-specific EIA studies
need for technology standards (BAT)
Mitigation measures exist for all significant impacts
sustainable desalination is technically feasible,
even with existing technologies
three examples

26. Mitigating energy use & GHG emissions
Minimization:
• energy use minimized to reduce costs in most projects
by using state of the art technology
Compensation:
of energy use if considered significant environmental impact
• most countries entered an international agreement
to reduce GHGs (Kyoto Protocol)!
• Australia:
all SWRO projects use indirect renewable energy
• Carlsbad project, Southern California:
Climate Action Plan at an estimated
US$ 76 million imposed on the project

27. Mitigating salinity impacts
Regulatory mixing zones:
• define the spatial & temporal distribution limit
of the concentrate plume
Whole effluent toxicity (WET) tests:
• determine the safe dilution ratio of the concentrate
• to be met at the edge of the regulatory mixing zone
Modeling studies:
• determine the best diffuser location and design
to achieve the safe dilution ratio
Field monitoring studies
• to detect possible ecological impacts using a
before-after, control-impact (BACI) approach

28. Mitigating chemical use
Treatment:
of all intermittent wastes
• pretreatment backwash (media filters, UF/MF)
• cleaning solutions (SWRO, UF/MF membranes)
Substitution:
of harmful chemicals where possible
• Tampa Bay (Florida), London (UK), Jumeirah (UAE):
chlorine replaced by chlorine dioxide (ClO2) due
to elevated chlorination by product formation
• 2 plants in the Middle East:
offline use of DBNPA (U.S. EPA approved biocide) to
control regrowth of biofouling organisms

29. Conclusions
Resource-intensive process with significant impacts
need for project- and site-specific EIA studies
need for technology standards (BAT)
Mitigation measures exist for all significant impacts
sustainable desalination is technically feasible,
even with existing technologies
Compensation measures, advanced technology, and
extensive environmental studies increase water costs
BUT: sustainable desalination is still economically viable