Nano-filter technology can clean dirty water free from heavy metals in time over 100 times faster than current technology, finds a new study. The findings of this study are published in the journal of Advanced Functional Materials. Simple to make and simple to scale up, the technology harnesses naturally occurring nanostructures that grow on liquid metals.
‘This nano filter has shown that it can remove lead and oil from water, but it also has the potential to target other common contaminants.’
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The RMIT University and University of New South Wales (UNSW) researchers behind the innovation have shown it can filter both heavy metals and oils from water at extraordinary speed.RMIT researcher Dr. Ali Zavabeti said water contamination remains a significant challenge globally - 1 in 9 people have no clean water close to home.
"Heavy metal contamination causes serious health problems and children are particularly vulnerable," Zavabeti said.
"Our new nano-filter is sustainable, environmentally-friendly, scalable and low cost.
"We've shown it works to remove lead and oil from water, but we also know it has potential to target other common contaminants.
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"With further development and commercial support, this new nano-filter could be a cheap and ultra-fast solution to the problem of dirty water."
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"The technique is potentially of significant industrial value since it can be readily upscaled, the liquid metal can be reused, and the process requires only short reaction times and low temperatures," Zavabeti said.
Project leader Professor Kourosh Kalantar-zadeh, Honorary Professor at RMIT, Australian Research Council Laureate Fellow and Professor of Chemical Engineering at UNSW, said the liquid metal chemistry used in the process enabled differently shaped nano-structures to be grown, either as the atomically thin sheets used for the nano-filter or as nano-fibrous structures.
"Growing these materials conventionally is power intensive, requires high temperatures, extensive processing times and uses toxic metals. Liquid metal chemistry avoids all these issues, so it's an outstanding alternative."
How it works!
The groundbreaking technology is sustainable, environmentally-friendly, scalable and low-cost.
The researchers created an alloy by combining gallium-based liquid metals with aluminum.
When this alloy is exposed to water, nano-thin sheets of aluminum oxide compounds grow naturally on the surface.
These atomically thin layers - 100,000 times thinner than a human hair - restack in a wrinkled fashion, making them highly porous.
This enables water to pass through rapidly while the aluminum oxide compounds absorb the contaminants.
Experiments showed the nano-filter made of stacked atomically thin sheets was efficient at removing lead from water that had been contaminated at over 13 times safe drinking levels and was highly effective in separating oil from water.
The process generates no waste and requires just aluminum and water, with the liquid metals reused for each new batch of nanostructures.
The method developed by the researchers can be used to grow nano-structured materials as ultra-thin sheets and also as nano-fibres.
These different shapes have different characteristics - the ultra-thin sheets used in the nano-filter experiments have high mechanical stiffness, while the nano-fibers are highly translucent.
The ability to grow materials with different characteristics offers opportunities to tailor the shapes to enhance their different properties for applications in electronics, membranes, optics, and catalysis.
Source-Eurekalert