Researchers have developed low energy desalination technology to reduce costs and energy use in water purification.
Desalination, the process of turning seawater into freshwater, is a lifeline for many arid regions. However, traditional methods are expensive and require large amounts of energy and chemicals. Now, researchers have developed a breakthrough in low-energy desalination technology that could make the process cheaper and more sustainable.
Scientists from Rice University and the University of Michigan have designed a new method to remove boron, a common seawater contaminant, without the need for extra chemical treatments.
Their approach, which uses carbon cloth electrodes, could reduce desalination costs by up to 15%, or about 20 cents per cubic meter of treated water. This advancement, recently published in Nature Energy, could save large desalination plants millions of dollars annually.
Most desalination plants today use reverse osmosis, a process that forces seawater through membranes to remove salt. While effective, reverse osmosis does not eliminate boron, a contaminant that can be harmful at high levels.
To remove boron, plants typically add chemicals to change its charge, making it easier to filter out. This extra step increases costs and requires more energy and chemicals.
For this reason, large-scale desalination has been mostly limited to wealthy nations like Saudi Arabia and the United Arab Emirates, where the high costs can be absorbed. Countries with fewer resources often struggle to afford the technology, despite facing severe water shortages.
While reverse osmosis remains the most widely used desalination technology, alternative methods exist, each with its own advantages and drawbacks. Electrodialysis, for example, uses electrically charged membranes to separate salt and other ions but is typically more effective for brackish water than seawater.
Another common method, multi-stage flash distillation, relies on heat to evaporate and condense water but demands high energy inputs, making it costly.
The newly developed low energy desalination technology offers a middle ground by efficiently targeting boron removal without additional chemicals.
Unlike traditional approaches that rely on extra filtration steps, the carbon cloth electrode system simplifies the process, reducing both energy consumption and operational costs.
The process works by splitting water into positive hydrogen ions and negative hydroxide ions. The hydroxide ions attach to the boron, changing its charge. The carbon electrodes then efficiently capture the negatively charged boron, leaving behind purified water.
The hydrogen and hydroxide ions eventually recombine, making the process more efficient and reducing chemical waste.
Several regions facing severe water shortages could benefit significantly from this new technology. In North Africa, countries like Egypt and Algeria rely heavily on desalination to supply drinking water, but high operational costs limit their ability to expand desalination capacity. Implementing low energy desalination technology could make water production more affordable and sustainable.
Similarly, coastal regions in India, where groundwater contamination is a major issue, could integrate this technology into existing desalination plants to reduce energy use and lower chemical dependency. In California, where drought conditions frequently strain water resources, this innovation could efficiently supplement traditional desalination plants, making clean water more accessible.
This innovation could lower operational costs for desalination plants and make the technology more accessible to countries that struggle with water scarcity. Reducing energy consumption also means lowering greenhouse gas emissions, making desalination more environmentally friendly.
For large desalination plants, which treat millions of cubic meters of water each year, a 15% cost reduction could translate to millions of dollars in savings. Additionally, reducing chemical use reduces pollution risks associated with chemical disposal in marine environments.
The cost of adopting low energy desalination technology depends on factors such as plant size, existing infrastructure, and regulatory approvals. Researchers estimate that integrating the technology into current desalination systems could require an initial investment of several million dollars per facility. However, with projected savings of 15% per year, many plants could recover their investment within five to ten years.
Scaling up production of the carbon cloth electrodes will also be necessary before the technology can be widely adopted. Researchers expect pilot projects to launch within the next two to three years, with full-scale implementation possible within a decade if results remain promising.
While the new technology is promising, it still needs further testing and scaling before it can be widely adopted. Researchers are exploring ways to integrate this method into existing desalination plants without requiring major infrastructure changes.
Another challenge is ensuring long-term durability. The effectiveness of the carbon electrodes over extended periods needs to be studied to determine whether they degrade or lose efficiency over time. If successful, this technology could pave the way for a new generation of more affordable and sustainable desalination plants.
As water shortages become more severe in many parts of the world, improving desalination efficiency is critical. The development of low energy desalination technology could be a game changer, making fresh water more affordable and accessible to millions. With further research and investment, this innovation could help solve one of the most pressing environmental challenges of our time.
