2. Desalination Definition
S Desalination is the process of removing salts and minerals
from sea water in order to create drinking water and irrigation.
S There are currently 14,500 desalination plants operating world
wide.
S 230 million people rely on this process for their daily water
usage.
3. Problem Definition
S 97.5% of the Earth's water is saline. Accessible fresh water
makes up .75% of the world's 2.5% fresh water supply.
S Increasing water demands attributed to population and
industrialization increase coupled with shrinking aquifer
reserves and deteriorating water infrastructure are putting a
strain on the world's fresh water supply.
S The UN estimates by 2025, 30 of countries will be water
scarce and 18 are in the Middle East and N. Africa.
S At least 36 states are expected to face water shortages
within the next 5 years.
Desalination Methods
6. Environmental Impacts
S Highly brine wastewater can be discharged back into the
sea.
S Local temperature increases at discharge locations.
Concentration of heavy metals in waste stream.
S Decreases demand on unsustainable sources of water
(groundwater, surface water)
7. Economic Impacts
S Desalination is currently more expensive than traditional
water extraction methods.
S Can range from 65-95 cents a cubic foot.
S Compared with groundwater extraction 50-65 cents a
cubic foot.
S Creates local jobs, can utilize waste heat from power
plants
8. Cogeneration
S The production of electricity using waste heat (as in
steam) from an industrial process or the use of steam
from electric power generation as a source of heat
S Distillation plants use this energy saving
technique because the excess heat helps
heat up the water
9. Sociological Impacts
Effect of pollution on local community, depending on the
energy sources.
Less chance of supply disruptions.
Placement of the facility (environmental injustice)
10. Plant Regulations: The Big Ones
S No depositing or dumping any brine material within sanctuary
boundaries. (Permit required)
S A permit is also required to dump brine material outside of
the boundaries, that is approved by a government body.
S No actions in building shall harm or disturb the natural
seabed (pipes, chemicals, etc.)
11. Compliance Issues
S Brine Disposal
S Evaporation pits
S Dumping back into the ocean
S Limiting environmental impact with emissions since
desalination requires a lot of energy input.
S Protecting the marine ecosystem
12. Future
S Desalination IS our future! (competition with waste
water treatment)
S Necessary evil
S Best Management Practices
S further develop environmental standards
S proper waste disposal
S Increase use of cogeneration and renewable
energies
S Improve technology to decrease price
13. Final Exam Questions
Question: What is desalination?
Answer: The process of converting undrinkable saline water into
fresh water.
Question: What percent of the Earth's water is saline?
Answer: 97.5%
