A global research team has managed to transform Brackish water and seawater in drinking water safe and clean in less than 30 minutes using metal-organic frames (MOF) and sunlight, as published in the journal ‘Nature Sustainability’.
In a discovery that could provide millions of people around the world with drinking water, the researchers were not only able to filter harmful particles from the water and generate 139.5 liters of clean water per kilogram of MOF per day, but they also performed this task with more energy efficiently than current desalination practices.
The World Health Organization (WHO) suggests that good quality drinking water should have a total dissolved solid (TDS) of
The main author, the professor Huanting Wang, of the Monash University Chemical Engineering Department, in Australia, highlights that this work has opened a new direction to design materials sensitive to stimuli for energy efficient and sustainable desalination and water purification.
“Desalination has been used to address water scarcity around the world. Due to the availability of brackish and sea water, and because desalination processes are reliable, treated water can be integrated into existing aquatic systems. with minimal risks to health, “he explains.
“But evaporative thermal desalination processes consume a lot of energy and other technologies, such as reverse osmosis, have several drawbacks, including high energy consumption and the use of chemicals in cleaning and dechlorination of membranes,” he adds.
The expert explains that “sunlight is the most abundant and renewable energy source on Earth. Our development of a new adsorption desalination process using sunlight for regeneration provides an efficient desalination solution in terms of energy and sustainable from an environmental point of view. “
Metalorganic structures are a class of compounds consisting of metal ions that form a crystalline material with the largest surface area of any known material. In fact, MOFs are so porous that they can fit the entire surface of a soccer field in one teaspoon.
The research team created a dedicated MOF called PSP-MIL-53. This was synthesized by introducing poly (spiropyran acrylate) (PSP) into the pores of MIL-53, a specialized MOF well known for its respiratory effects and transitions on the adsorption of molecules such as water and carbon dioxide.
The researchers showed that PSP-MIL-53 could produce 139.5 liters of fresh water per kilogram of MOF per day, with low energy consumption. This was due to the desalination of 2,233 ppm of water from a river, lake or aquifer.
Professor Wang notes that this highlights the durability and sustainability of using this MOF for future clean water solutions. “This study has successfully shown that photosensitive MOFs are a promising, energy efficient and sustainable adsorbent for desalination,” he adds.
“Our work provides an interesting new route for the design of functional materials to use solar energy to reduce energy demand and improve the sustainability of water desalination,” he continues. “These sunlight-sensitive MOFs can potentially be functionalized. further to obtain low-energy and environmentally friendly mineral extraction media for sustainable mining and other related applications. “