Desalination Process

Questions and Answers

What is the minimum concentration of dissolved salts in water for it to be considered moderately saline?

35,000 ppm

1,000 ppm

10,000 ppm (correct)

3,000 ppm

What is the purpose of applying pressure to a solution like seawater in reverse osmosis?

To add more dissolved salt molecules to the water

To decrease the concentration of water molecules

To increase the concentration of water molecules

To remove dissolved salt molecules from the water (correct)

What is the primary reason why humans cannot drink saline water?

It is too sour

It is too cold

It contains too many dissolved salt molecules (correct)

It is too sweet

What is the concentration of dissolved salts in ocean water?

35,000 ppm Signup and view all the answers

What is the term for the movement of fresh water through a semipermeable membrane when pressure is applied to a solution?

Reverse Osmosis Signup and view all the answers

What is the concentration of dissolved salts in freshwater?

Less than 1,000 ppm Signup and view all the answers

What is the purpose of desalination?

To remove dissolved salt molecules from saline water Signup and view all the answers

What is the term used to describe the amount of dissolved salt in water?

Concentration Signup and view all the answers

What is the salinity level of the Dead Sea in ppm?

280,000 Signup and view all the answers

What is the purpose of distillation in water treatment?

To remove impurities and minerals from the water Signup and view all the answers

What is the main disadvantage of reverse osmosis desalination?

It is an expensive process Signup and view all the answers

Which region has the highest capacity for desalination?

Middle East Signup and view all the answers

What is the approximate capacity of the largest inland municipal desalination plant in the world?

27.5M GPD Signup and view all the answers

What is the average cost to produce 326,000 gallons of desalinated water from brackish groundwater in Texas?

$357 to $782 Signup and view all the answers

What is the primary use of distilled water?

Car batteries and steam irons Signup and view all the answers

Which of the following is NOT a method of desalination?

UV treatment Signup and view all the answers

What percentage of worldwide desalination capacity is used in the Middle East and North Africa?

76% Signup and view all the answers

What is the name of the largest industrial seawater desalination plant in Texas?

M&G Resins USA, LLC Signup and view all the answers

What percentage of Perth, Australia's freshwater comes from desalination plants?

45% Signup and view all the answers

How many billion liters of seawater are converted to freshwater by Perth's desalination plants each year?

128 Billion Liters Signup and view all the answers

What percentage of Australia's total electricity generation comes from renewable energy sources?

21% Signup and view all the answers

What is a major environmental impact of desalination?

Increased fossil fuel dependence Signup and view all the answers

What is the purpose of diffusers in desalination?

To stimulate brine mixing with ocean water Signup and view all the answers

What is a limitation of desalination as a strategy to bolster regional water supplies?

It is too expensive Signup and view all the answers

What is the estimated number of fish larvae and other marine life killed annually by open ocean intakes used by coastal power plants in California?

70 billion Signup and view all the answers

What is the ratio of ocean water to freshwater produced in ocean desalination?

2:1 Signup and view all the answers

Why is brine disposal a challenge in desalination?

It has a higher salt concentration than seawater Signup and view all the answers

What is the goal of the energy strategy at Perth's desalination plants?

To sustainably manage energy needs through improving energy efficiency and focusing on renewable sources Signup and view all the answers

Study Notes

Desalination

Desalination is the process of converting saline water into freshwater, which is essential for human consumption.
Desalination is becoming increasingly important worldwide to provide people with freshwater.

What is Desalination?

Desalination involves forcing water through a semi-permeable membrane to remove salt molecules, resulting in freshwater.
The movement of freshwater through the membrane is called reverse osmosis.

Salinity of Water

Water is considered saline if it contains significant amounts of dissolved salts, measured in parts per million (ppm).
Freshwater has less than 1,000 ppm, while highly saline water has 10,000-35,000 ppm.
Ocean water has approximately 35,000 ppm of salt.

Distillation

Distillation is a method of desalination that involves boiling water to produce steam, which is then cooled to produce freshwater.
Distilled water is free of minerals and salts, making it safe to drink but tasteless and flat.
Distillation is an ancient desalination method still used today.

Reverse Osmosis

Reverse osmosis is an effective method of desalination that uses a semi-permeable membrane to remove salt molecules from water.
However, reverse osmosis is an expensive process.

Desalination Facts

In 2015, there were 18,426 desalination plants operating worldwide, producing 22,930 million gallons per day (MGD) of freshwater.
Desalination plants provide water for approximately 300 million people worldwide.
The Middle East is the largest user of desalinated water, with 70% of worldwide capacity.
The United States is also a significant user of desalinated water, particularly in California and Florida.

Texas Desalination Facts

Texas has a municipal desalination capacity of approximately 142 MGD.
There are 85 MGD of brackish groundwater desalination and 54 MGD of brackish surface water desalination in Texas.
The largest inland municipal desalination plant in the world is located in El Paso, Texas, with a capacity of approximately 27.5 MGD.

Perth, Australia's Desalination Plants

Perth, Australia's desalination plants produce 45% of the city's freshwater from seawater.
The plants have a capacity of 128 billion liters of freshwater per year, equivalent to approximately 34 billion gallons.

Negatives of Desalination

Brine water, a hyper-saline slurry, is a disposal challenge and can harm the environment if not mixed with other water sources.
Desalination is energy-intensive and can increase fossil fuel dependence, contributing to environmental harm.
Surface water intakes used in desalination can harm marine life, such as fish and larvae.
Desalination is an expensive and inefficient process, making it a costly strategy to bolster regional water supplies.

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Description

Learn about the process of desalination, which converts saline water into freshwater, and its increasing use around the world to provide freshwater. Explore reverse osmosis, a key method of desalination.