Sustainable alternative water supply systems

Freshwater is a critical resource which is intrinsically limited (only about 0.8% of Earth’s water is accessible freshwater) and chronically scarce. Therefore, given the rapidly dwindling supply and unceasing demand that multiplicatively exacerbates global freshwater scarcity, achieving water supply security has become a principal requirement and an endeavour for humankind. Water scarcity is considered a long-term threat to life on Earth; thus, alternatives are sought within the inherently limited options. To that end, desalination, an enabling technology alternative, helps alleviate this problem by converting saltwater to freshwater. Desalination has advanced expeditiously from the lab– and pilot-scale in the 1950s to over 100 million m3/d of freshwater production capacity in 2021, providing safety and security to the global water supply. Despite this, desalination is heavily contested for its high costs and negative environmental impacts. Given that background, the underlying fundamental query inquired herein is what should be done to augment the water supply to address the current water scarcity and future water security issues whilst improving the socio-economic impacts and reducing the environmental pressures arising from alternative water supply technologies such as seawater reverse osmosis desalination (SWRO)? To that end, this work systematically and sequentially investigated three sub-queries with increasing complexity.