Desalination

• 1. Desalination:Creating fresh water for the futureAshley Hall Kelly Kramer Dan SpisakS

2. Desalination DefinitionS Desalination is the process of removing salts and mineralsfrom sea water in order to create drinking water and irrigation.S There are currently 14,500 desalination plants operating worldwide.S 230 million people rely on this process for their daily waterusage. 3. Problem DefinitionS 97.5% of the Earths water is saline. Accessible fresh water makes up .75% of the worlds 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 worlds 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 4. Types of Desalination-ReverseOsmosis 5. Types of Desalination-Distillation 6. Environmental ImpactsS Highly brine wastewater can be discharged back into thesea.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 ImpactsS Desalination is currently more expensive than traditionalwater extraction methods.S Can range from 65-95 cents a cubic foot.S Compared with groundwater extraction 50-65 cents acubic foot.S Creates local jobs, can utilize waste heat from powerplants 8. CogenerationS 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 heatS Distillation plants use this energy savingtechnique because the excess heat helpsheat up the water 9. Sociological ImpactsEffect of pollution on local community, depending on theenergy sources.Less chance of supply disruptions.Placement of the facility (environmental injustice) 10. Plant Regulations: The Big OnesS 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 IssuesS Brine DisposalS Evaporation pitsS Dumping back into the oceanS Limiting environmental impact with emissions sincedesalination requires a lot of energy input.S Protecting the marine ecosystem 12. FutureS Desalination IS our future! (competition with waste water treatment)S Necessary evilS Best Management PracticesS further develop environmental standardsS proper waste disposalS Increase use of cogeneration and renewableenergiesS Improve technology to decrease price 13. Final Exam QuestionsQuestion: What is desalination?Answer: The process of converting undrinkable saline water intofresh water.Question: What percent of the Earths water is saline?Answer: 97.5%