But there’s one problem: desalination produces a typically hypersaline concentrate discharge called “brine” that requires disposal, which is both costly and has associated negative environmental impacts.
In 2000, the volumes of desalinated water produced by thermal technologies and RO were approximately equal at 11.6 million m3/day and 11.4 m3/day respectively, together accounting for 93% of the total volume of desalinated water produced.
The current production of desalinated water from RO now stands at 65.5 million m3/day, accounting for 69% of the volume of desalinated water produced.
Almost half of the global desalination capacity is located in the Middle East and North Africa region (48%), with Saudi Arabia (15.5%), the United Arab Emirates (10.1%), and Kuwait (3.7%) being the major producers in both the region and globally.
Realizing the vast potential of desalinated water remains a challenge due to specific barriers, predominantly associated with the relatively high economic costs and a variety of environmental concerns, such as brine byproducts.
Global brine production is concentrated in the Middle East and North Africa, which produces almost 100 million m3/day of brine, accounting for 70.3% of global brine production.
As with desalinated water production, high income countries produce the vast majority of global brine (77.9%).
The study also notes economic opportunities to use brine in aquaculture, such as to irrigate salt tolerant species, to generate electricity, and to recover the salt and metals contained in brine, including magnesium, gypsum, sodium chloride, calcium, potassium, chlorine, bromine, and lithium.
Substantial efforts, innovation and research are required to both (a) reduce the volume of brine being produced (i.e. increase the efficiency of the desalination process) and (b) to treat and/or use the brine that is produced in an economically viable and environmentally friendly way.
Metal and salt recovery from brine is an option, although high economic costs and energy demands remains a significant barrier to more widespread application.