Desalination

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Shevchenko BN350 desalination unit situated on the shore of the Caspian Sea.

Desalination means any process that removes the excess salt and other minerals from water in order to obtain fresh water suitable for animal consumption or irrigation.

If almost all of the salt is removed for human consumption, sometimes the process produces table salt as a by-product.

Desalination of brackish water is done in the United States in order to meet treaty obligations for river water entering Mexico. Several Middle Eastern countries have energy reserves so great that they use desalinated water for agriculture. Saudi Arabia's desalination plants account for about 24% of total world capacity. The world's largest desalination plant is the Jebel Ali Desalination Plant (Phase 2) in UAE. It uses multi-stage flash distillation, dual-purpose and it is capable of producing 300 million cubic meters of water per year.[1]

Methods[change | change source]

  1. Distillation
    1. Multi-stage flash (MSF)
    2. Multiple-effect (MED|ME)
    3. Vapor compression (VC)
    4. Evaporation/condensation
  2. Membrane processes
    1. Electrodialysis reversal (EDR)
    2. Reverse osmosis (RO)
    3. Nanofiltration (NF)
    4. Forward osmosis (FO)
    5. Membrane distillation (MD)
  3. cold
  4. thermal
  5. Solar humidification
  6. Methane hydrate crystallisation
  7. High grade water recycling

The traditional process used in these operations is vacuum distillation — essentially the boiling of water at less than atmospheric pressure, and thus a much lower temperature than normal. Due to the reduced temperature, energy is saved.

References[change | change source]

  1. Saline Water Conversion Corporation

Other websites[change | change source]