Development on sustainable water recycle, reuse and management

The implementation of seawater desalination, a key strategy to secure fresh water supply inarid and coastal regions, is greatly thwarted by its high cost relating to high energy andequipment cost associated with pressure and the high system or membrane fouling associatedwith the bi-valence ions in the sea water. Given increasing regional water scarcity and thatalmost half of the world's population lives within ۱۰۰ km of an ocean, seawater represents avirtually infinite water resource. However, its exploitation is presently limited by the significantspecific energy consumption (kWh/m۳) required by conventional desalination technologies,further exasperated by high unit costs ($/m۳) and environmental impacts including GHGemissions (g CO۲-eq/m۳), organism impingement /entrainment through intakes, and brinedisposal through outfalls. Nano filtration (NF), a lower pressure membrane process with highrejection for divalent ions, had been identified as a key component to reduce the costs relating toboth pressure and fouling in the desalination process. Lower cost seawater desalination processeshad been developed by integrating NF with various types of desalination technologies includingreverse osmosis (RO), forward osmosis (FO), multistage flash (MSF), multi effect distillation(MED), membrane distillation (MD). This paper explores the state-of-the-art in present seawaterdesalination practice, emphasizing membrane-based technologies, while identifying futureopportunities in step improvements to conventional technologies and development of emerging,potentially disruptive, technologies through advances in material science, process engineering,and system integration.

کلیدواژه ها:

seawater desalination ، water supply ، sustainable water recycle