Desalination of Water
While renewable, the world’s water supply is being depleted faster than it is being refilled. This has caused ¼ of the global economy to be at risk because of non-sustainable water use. A solution to the unsustainable water crisis is desalination. 97% of all water on Earth is non-usable salt water. The other 3% is fresh, usable water, however ~68% of that water is locked up in glaciers, and 30% is stored in underground aquifers. The remaining 1-2% comes from things such as ground ice, fresh water lakes, and rivers. Desalination (the removal of salt) would allow water to be consumed from an almost fully renewable source, the oceans. As it stands, today we face the risk of running out of usable water; rivers are running dry, and underground aquifers are being drained faster than they refill. By 2050, the population will grow to 9 billion, requiring more water to be used in agriculture, industry, and by people.
Desalination is a process that is already beginning to occur around the world in places including the US and (most notably) the Middle East. Over 50% of renewable water in the Middle East has been used, and therefore desalination is more common in those areas. The most common processes of desalination are osmosis and multistage flash distillation. Saudi Arabia has multistage flash distillation plants as well as osmosis plants for desalination. Places that require desalination most are dry, coastal areas. In the US, the largest desalination plant is located in Florida, but other states such as Texas and California are also beginning to develop desalination plants.
As mentioned above, there are two main procedures for desalinating water – osmosis and multistage flash distillation. There are two ways in which osmosis can be used to desalinate water, reverse osmosis and forward osmosis. Of the two, reverse osmosis is the one used more frequently. In reverse osmosis, pressure is used to move water through a membrane, which...
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