Seawater Desalination Plant (SDP)
The filtered seawater is then forced under pressure through special membranes whereby the osmosis process that normally occurs in nature is reversed. The pores in the membranes are so tiny that salt, bacteria, viruses and other impurities are separated from the seawater. In essence they act like microscopic strainers. About half of the water that enters the plant from the sea becomes fresh drinking water. The salt and other impurities removed from the sea water is then returned to the ocean via diffusers, which ensures it mixes quickly and prevents impacted the marine environment.
The desalinated water is then subject to further treatment to meet drinking water standards before it reaches our customers.
Our desalination plants meet stringent environmental protection criteria and are designed to have minimal impact on the surrounding environment.
Our 2 desalination plants are located near the open ocean. Due to the high energy swell, the concentrated seawater discharged during the process mixes very quickly with the surrounding seawater. The offshore discharge and intake pipelines are designed and located to minimise any effects on sensitive marine habitats, such as seagrasses and reef systems.
Seawater Desalination Preface
Seawater Desalination is a process in which salt and other constituents are removed to produce pure water. Approximately 75 million people worldwide rely on desalination and that number is expected to grow as freshwater resources are stressed by population growth and millions more move to coastal cities with inadequate freshwater resources . Desalination is most widely used in arid regions; more than half of the world’s desalination capacity (volume) is located in the Middle East and North Africa. Seawater accounts for over 50% of desalination source water worldwide. However, as of 2005 in the United States, only 7% of desalination plants used seawater. Brackish waters made up the majority of source waters for desalination, with most of the remainder consisting of river waters and wastewaters .
Two streams of water result from desalination: (1) a pure product water and (2) a high-concentration waste stream or brine. The principal desalination methods fall into two categories: thermal processes (Figure 1) and membrane processes (Figure 2).Thermal treatment uses heat to evaporate the water, leaving behind the dissolved salts, or waste stream, and separating it from pure water. Membrane processes use reverse osmosis and high pressure to force saltwater through very fine, porous filters that retain the salts, leaving pure water on one side of the membrane and the waste stream on the other side. Since a great majority of earth’s water is found in the seas and oceans, desalination creates an opportunity for coastal communities to access virtually unlimited freshwater sources. In addition, desalination techniques can be used to purify brackish water in areas with seawater intrusion. In light of climate change adaptation, this is also a crucial resource for areas where existing freshwater resources can no longer support local populations or be rehabilitated to meet the freshwater demands.