desalination and perth

definition of reverse osmosis?

• the movement of fresh water through a semipermeable
  membrane when pressure is applied to a solution (such as
  seawater) on one side of it

• Water, containing dissolved salt molecules, is forced through
  a semi-permeable membrane (essentially a filter), in which
  the larger salt molecules do not get through the membrane
  holes but the smaller water molecules do.

what does saline water mean?

• Water that is saline contains significant amounts of dissolved salts, referred to as a "concentration"

• The concentration is the amount (by weight) of salt in water, as expressed in "parts per million" (ppm)

*parameters for saline water?

• Freshwater - Less than 1,000 ppm
• Slightly saline water - From 1,000 ppm to 3,000 ppm
• Moderately saline water - From 3,000 ppm to 10,000 ppm
• Highly saline water - From 10,000 ppm to 35,000 ppm
• Ocean water contains about 35,000 ppm of salt.

what is the dead sea salt content?

280,000 ppm (8x saltier than sea water)

located between jordan and israel

what are the two ways to desalinate water?

1. running a still

2. reverse osmosis

*what is distilled water?

• Distilled water is water that has been boiled to become steam and then cooled to become water again.

• It's free of minerals and salts.

• Distilled water is used in car batteries and in steam irons.

• Distilled water prevents the iron or coffee pot from getting clogged up inside from minerals.

• It also has various medical and industrial uses.

DISTILLED WATER IS FREE OF CALCIUM, MAGNESIUM, AND SODIUM

what is brine?

• Extracted salts, minerals, and a percentage of source water mix to form a hyper saline slurry commonly referred to as brine.
• Brine has a much higher salt concentration compared to salt water, which creates disposal challenges.
• Brine waste is commonly disposed of in the ocean. To reduce environmental impacts during disposal, brine can be mixed with other water sources to reduce salinity and/or discharged through diffusers.
• Diffusers stimulate brine mixing with ocean water and are used to disperse brine at several different discharge points from desalination facilities.

*perth, australia facts:

• 45% of their freshwater comes from the sea

• 40 from groundwater

what are the negatives to desalination?

• Brine Water
• Environmental Impacts
• Overall Solution Limitations

*what are the environmental impacts of brine?

• Most forms of desalination are energy-intensive.
• Desalination has the potential to increase fossil fuel dependence.
• Desalination surface water intakes are a threat to marine life.
• Mature fish, larvae, and other marine life can be injured or killed when
they become trapped or sucked into open water surface intake pipes.
• The State Water Resources Control Board estimates that open ocean
intakes used by coastal power plants in California kill 70 billion fish
larvae and other marine life on an annual basis.
• These same open ocean intakes are being proposed for use at
desalination plants throughout California.

Desalination’s energy-intensive process is expensive and
environmentally harmful, making it a costly strategy to bolster
regional water supplies.
• The average price of Ocean-Water Desalination is often 2-4 times
more expensive than other water sources.
• Ocean desalination is not efficient, requires roughly two gallons of
ocean water for every one gallon of freshwater produced.

how much water is wasted in small scale reverse osomosis?

40%