Reverse osmosis concentrate management technologies for desalination plants

The growing demand for fresh water is partially satisfied by desalination plants that increasingly use membrane technologies and among them reverse osmosis (RO) to produce purified water. One of the main drawbacks with RO is the volume of concentrate produced during the process. Several technologies and process configurations, which are accessible for further treatment of RO concentrate, reduce the reject volume. Development of energy-efficient, cost-effective, and environmentally benign concentrate management systems is critical if desalination is to become a major part of a sustainable water future. In this paper, treatment technologies are discussed according to their classification as membrane-based, thermal-based, or emerging technologies. Membrane-based technologies are less energy intensive in comparison with thermal-based technologies, but when the concentrate water quality is complex, the use of membrane-based technologies is restricted. Thermal-based technologies are capital intensive, consume a significant amount of energy and are not suitable for large flow rates. This review also addresses emerging technologies that show potential to efficiently treat RO concentrate, but these are still under development and operational data on large scale facilities are limited.

Keywords:

Desalination , Concentrate management , Reverse osmosis , Water recovery