Cooling down brine to recover minerals from water treatment
As part of the European Zero Brine research project, a pilot has started in Rotterdam, the Netherlands, to recover minerals from the remaining brine of water treatment with reverse osmosis.
One of the technologies used, is an Eutectic Freeze Crystallizer that cools down the brine to a temperature when both salt and ice crystals are formed.
Recovery of reusable substances
The pilot aims to recover sulphate salts and sodium bicarbonate from brine that remains at a production plant for ultrapure demineralised water. The Demineralised Water Plant (DWP) is operated by water utility Evides and is one of the largest in Europe. The plant uses fresh surface water to produce ultrapure demineralised water for the surrounding industries in the port of Rotterdam.
The plant uses reverse osmosis (RO) membranes for the removal of all necessary substances in order to be able to meet the requirements for demineralised water. The removed substances are separated in the concentrate stream of the RO and end up in the remaining brine.
The Zero Brine project aims at the development of new technologies to further reduce the volume of this RO brine at industrial sites by recovering substances that can be reused. The project conducts several pilots at industrial sites across Europe, including Poland, Spain, Turkey and the Netherlands.
The recently started pilot at Evides is a second pilot. Last year Zero Brine started a first pilot that treated the spent regenerant solution of the IEX unit to recover high purity calcium, magnesium, salt, and clean water.
This second pilot aims to explore the use of new and existing technologies to treat the reverse osmosis (RO) concentrate and recover sulphate salts, sodium bicarbonate, regeneration solution (NaCl rich stream), and clean water. The technologies being used, are provided by project consortium members including UK-headquartered water treatment company Arvia (TOC removal), Dutch water treatment company Lenntech (nanofiltration and RO), the Delft University of Technology (Eutectic Freeze Crystallizer), and the National Technical University of Athens (evaporator).
The pilot is also coordinated by the Delft University of Technology in the context of the Zero Brine project.