~ Desalination - Tap 4

Desalination is the fourth and final process whereby Singapore uses to increase its water supply.

Desalination starts when the sea water collected goes through a pre-treatment process where suspended particles are removed. After that, the water goes through reverse osmosis where the salt content and other impurities are removed. ( Reverse osmosis is the process whereby the water is moved across the membrane against the concentration gradient, from lower concentration to higher concentration. ) Pressure is exerted on the side which is more concentrated, in this case, the seawater, and forces the water molecules across the membrane, which results in the molecules to be at the side of fresh water. The water produced is very pure at this stage. After this, the water is remineralised. After treatment, desalinated water is blended with treated water before it is supplied to homes and industries situated in the western part of Singapore.

Desalination process.

 Singspring is the first and only desalination plant in Singapore. This plant produces 136,380 m³ of desalinated water per day, which meets 10% of Singapore’s water needs.

This desalination plant uses the technology of reverse osmosis to transform salt water into water fit for human consumption. Singspring has the largest membrane which makes this plant the largest membrane-based seawater desalination plant in the world at the time of its completion.

This method is seen viable as Singapore is surrounded by seawater and desalinating seawater is a potential way to make use of your surroundings and seawater is an unlimited supply, with a steady flow. This method is also cost and energy efficient. Another deciding factor is that the membrane used for desalination is getting cheaper. Adding on, desalination does not rely on rain water to function properly.