Desalination

Past, Present and Future

What is desalination ?

Desalination is the process of removing dissolved minerals, including salt, from water. Seawater, brackish water,surface water and treated wastewater can be treated with desalination. Desalination processes include distillation, electrodialysisreversal (EDR), and reverse osmosis (RO). In Florida, RO is the most widely used technology.

Desalination in Florida

The first desalination plant is in the United States was built in the 1840’s to serve troops at Fort Zachary Taylor in Key West, according to US News and World Report. Desalination in Florida expanded in the 1960s and today provides approximately 25 percent of Florida’s water supply.

Florida has:

  • More than 150 desalination plants
  • More than 515 million gallons per day (MGD) of
    desalination treatment capacity
  • Approximately 50 percent of the desalination
    capacity in the U.S.

Currently, Tampa Bay Desal is the largest seawater desalination plant in North America.lt is operated by Desalination can be used in conjunction with Tampa Bay Water, a regional water authority, and has aother water treatment processes. For rated capacity of 25 MGD.A 50 MGC desal plant is example, processes such as ultrafiltration (UF) under construction in CA.

Desalination Technology

Desalination can be used in conjunction with other water treatment processes. For example, processes such as ultrafiltration (UF) and nanofiltration (NF) can be used as a pretreatment process before using another desalination process such as RO.

Desalination Costs

The cost to produce water treated by a desalination process varies depending on:

  • Type of desalination technology utilized
  • Quality of the source water for the process

Desalination with distillation is a very energy intensive process, resulting in high operational costs, where as the RO process is typically the least energy intensive process. In addition, seawater desalination has higher capital and operational costs than brackish water desalination because of the high-grade non-corrosive equipment necessary in the seawater desalination process and the higher pressure necessary for the seawater desalination

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 Is it safe?

Yes. Desalination is a safe process that has been used for thousands of years. Today’s desalination technologies of distillation, EDR, and RO are process and the advanced processes carefully designed to make facilities them safe to use.

Challenges

Challenges with desalination include management of concentrate generated by the process and the power costs to operate desalination.

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Future of Desalination

  • Limited fresh water resources
  • Population continues to grow
  • Projections are another 500 MG from desalination over the next 20 years
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