Desalination of brackish groundwater to improve water quality and water supply

Abstract

Brackish groundwater desalination has and will continue to play a critical role in improving water quality and water supply in many parts of the world. While numerous methods exist for desalination, membrane-based desalination technologies are used without exception in treating brackish groundwater. The two most widely adopted processes are reverse osmosis (RO) (pressure-driven desalination) and electrodialysis (ED) (electric potential-driven desalination). Selection of the appropriate technology is made based on feedwater and target product water composition for a particular application, as well as environmental and cost considerations. This chapter outlines the key components of a typical brackish groundwater desalination facility that uses RO or ED, including required pretreatment of source water and posttreatment of product water. Desalination plant energy consumption and economics are discussed. Brine disposal is highlighted as a critical cost driver for inland brackish groundwater desalination. Environmental friendly alternatives to current brine disposal methods and conventional energy sources are considered. Because geography is a key consideration in desalination decision-making, regional and national trends in desalination capacity, spending, technology, and source water type are also investigated. The national trends focus on the following desalination players: United States, Saudi Arabia, China, Australia, Spain, and India.

Keywords

Desalination reverse osmosis electrodialysis reversal brackish groundwater brine management energy consumption cost geographic trends