Treating and recovering brine

According to GWI DesalData, some 13,500 desalination plants are now in operation all over the globe, producing approximately 83 million m3 of drinking water daily.

Environmental concerns are increasing globally due to a number of factors, including salinity gradients, effluent discharge speed, effluent dissolved oxygen levels, and toxic chemicals.

Most desalination players consider brine as a burdensome by-product and are looking for the cheapest and easiest solution to get rid of it.

The opportunity for recovery of constituents in brine offers the potential of an added value resource — including brine mining and brine as a source for electricity.

Brine includes many useful ions and recovering these materials economically could be one of the critical challenges for the water sector in the next few years.

The industry is also exploring the use of brine as a resource to produce electricity, leveraging the salinity-gradient power. Potential technologies include Pressure Retarded Osmosis, which consists of converting the osmotic pressure of a saline solution to hydraulic pressure, and Reverse Electrodialysis, which consists of converting salinity difference into electric current with ion-exchange...

As 2025 gets closer, the cost of discharging brine to the sea is expected to increase as public authorities are taking up the environmental issues and defining stricter regulations for seawater discharge. For example, Australia’s Environmental Protection Act 1993 and Water Act specifies as its first priority that brine is to be treated to produce usable products wherever feasible, and then...

Geoff Gage is a managing partner at Amane Advisors. He is based in Oxford, United Kingdom and serves clients across the water sector, with a focus on strategic and operational topics. He can be reached at ggage@amaneadvisors.com.