Abstract
Desalination is considered the most practiced method to overcome the mounting pressure of water scarcity. Regardless of outstanding performance and manifold advantages presented by desalination, growing concerns about its environmental footprints cannot be overlooked. Reject brine disposal releases numerous antifoaming, fouling resistance, antiscalants, antiturbidity, and corrosion inhibition additives into the marine environment; entrapment, entrainment, and impingement of marine organisms in water intake systems besides intensive energy usage which inextricably interwoven with air pollution, greenhouse gasses emission and noise pollution are major environmental adverse effects of desalination systems. This paper comprehensively explores aforesaid impacts besides offering several case-specific mitigative strategies like water/energy recovery, environmental impact assessment (EIA), CO2 sequestration, careful selection of land, careful intake and outfall design, brine mining, brine treatment, and application of green desalination technologies to countervail and minimize those undesirable environmental footprints. In this context, several green desalination technologies like functional water channels, gas hydrate-based desalination, energy recovery, hybrid desalination, renewable energy-based systems and temperature swing solvent extraction were discussed. Moreover, several brine mining methods were presented to simultaneously take advantage of the presence of precious materials in the reject brine stream, which can be advantageous from an economic standpoint. To ensure the removal of any potentially negative influences of desalination on human beings and the environment, conduction of stringent monitoring procedures is strongly crucial. Finally, it concludes that with considerable technical advancements in conventional desalination technologies and conduction of cutting-edge desalination systems along with the application of renewable energy sources, achieving a pollution-free and sustainable operation is reasonably sensible.