Development and application of brackish desalination equipment

Brackish water, a water source with salinity between freshwater and seawater, is currently a highly promising alternative water source. Brackish desalination equipment, thanks to technological innovation and adaptation to various scenarios, is gradually alleviating the global imbalance between water supply and demand.

This type of equipment is specifically designed for low-salinity water sources such as groundwater and estuarine seepage water. Through diverse technological means, it achieves efficient desalination and can effectively serve various water supply needs in arid regions, industrial water supply, and other scenarios.

Development trends in brackish desalination technology

Energy recovery system upgrade

Brackish water desalination technology is steadily improving towards greater energy efficiency and modularity. Traditional reverse osmosis technology remains the mainstream, with key advancements focusing on optimizing membrane modules and upgrading energy recovery systems.
The iSave™ energy recovery device developed by Australian company SAE can recover 95% of the remaining energy from concentrated brine, requiring only 1.7 kilowatt-hours of electricity to treat one ton of brackish water. The operating cost is approximately $0.36 per ton, representing a 60% energy saving compared to traditional equipment.

This technology has been widely used in Africa, on islands in Oceania, and in arid regions. Four desalination plants built in South Africa, each capable of processing 5,000 tons of water per day, utilize this technology and have successfully solved the water supply problems for local residents.

Scope of application expanded

Various innovative technologies are continuously expanding the scope of application for brackish water desalination equipment.
Professor Yat Li’s team in the United States combined 3D printing technology with capacitive deionization (CDI) to create a new generation of brackish water desalination equipment. This device does not rely on traditional membrane structures; instead, it uses positive and negative electrodes to adsorb salt ions from the water. When treating low-salinity water, it is significantly more energy-efficient than traditional methods, and the resulting concentrated brine has minimal environmental impact. They developed a porous conductive carbon material with a surface area of 3000 square meters per gram, and by combining it with a three-dimensional interpenetrating electrode structure, they have greatly boosted the desalination effect and provided a new approach for groundwater desalination in coastal areas.

Brackish desalination technology is developing steadily

Large companies’ investments in brackish water desalination technology are also driving the continuous development of this industry. Companies like Dow Chemical and Hydranautics produce reverse osmosis membranes that offer excellent desalination performance and long service life, making them highly competitive in the global market. Their developed anti-fouling membrane modules can handle complex brackish water compositions, reducing the frequency of equipment maintenance.

German company Meinert focuses on customized services, designing dual-membrane systems combining microfiltration and reverse osmosis for industrial applications. They have performed exceptionally well in wastewater recycling and desalination in industries such as electronics and chemicals.

What are the characteristics of customized desalination equipment?

The Middle East has a particular need for brackish water desalination equipment. The equipment used there is mostly corrosion-resistant, has a high output capacity, and can withstand the harsh environment of high temperatures and high salinity.
European and American regions, on the other hand, place more emphasis on environmental protection, striving to combine desalination equipment with clean energy sources such as solar and wind power, achieving a model of “producing clean water using green electricity.”
Flocean, a Norwegian startup company, has developed an underwater brackish water desalination module that uses the natural pressure of the deep sea to drive desalination, saving 30% to 50% of electricity compared to land-based equipment and also saving considerable space. It is expected to be commercially available in 2026 and will be able to meet water needs in various scenarios.

Summarize

From energy-efficient reverse osmosis technology to innovative membrane-free desalination solutions, and from arid regions to coastal areas, these brackish water desalination devices play a crucial role in various fields. In the future, as clean energy and new materials technologies become further integrated, the industry will continue to upgrade brackish water desalination equipment, cutting costs, boosting efficiency and making a far more significant contribution to the sustainable use of global water resources.