Technologies

Reverse Osmosis is a desalination method that is slightly more complex but less energy intensive. In this process, saltwater is pumped through a series of semi-permeable membranes, where water molecules pass through but salt particles are left behind. The salt water is pumped through the membrane by a pressure difference and the membrane almost acts as a filter. No heating is required and the water never changes it's state of matter, and the only major energy requirement is the pressurization of the salt water.

Advantages

-Low instillation cost and low maintenance

-Negligible environmental impacts

-High space/production capacity ratio

Disadvantages

-Extensive pre-treatment of water may be required

-Membranes are difficult to replace if damaged

-Disposal of brine

Forward Osmosis is like reverse osmosis, but backwards. The forward osmosis process operates on a natural pressure difference. for forward osmosis, a highly concentrated "draw" solution pulls the water molecules out of the salt water entering the system. Next, you can undergo a simpler separation of the draw solution and the water, leaving you with fresh water and the draw solution itself which is used in the process over and over again. Forward osmosis is one of the less popular desalination methods, and some suggest more development is needed before forward osmosis could be widely used.

Advantages:

-Uses a natural osmotic pressure difference thus less energy intensive than reverse osmosis.

-More tolerant of contaminants that would otherwise damage membranes in reverse osmosis.

-Forward osmosis gas potential in wastewater treatment, food processing and more.

Disadvantages:

-Difficulty in developing reliable and cost effective draw solutions.

-Difficulty in developing systems that require minimal post treatment treatment of recovered water

-Difficulty in integrating renewable energy to power the process.