Modified metal can strip impurities from wastewater

Researchers from Edith Cowan University (ECU) have developed a way to modify the atomic structure of iron to create a metal that can strip impurities from water in just a few minutes — a breakthrough that could be utilised in wastewater-heavy industries such as mining and textiles.

Led by Associate Professor Laichang Zhang, from ECU’s School of Engineering, the researchers were able to change the atomic structure of iron to form what is known as metallic glass. Whereas the atomic structure of traditional metals is very ordered, with the atoms forming a grid-like structure, metallic glass atoms have a much more disorganised composition.

“It is this disordered atomic structure that gives metallic glass its very interesting and useful characteristics,” Professor Zhang said.

A thin strip of the iron-based metallic glass developed by the researchers can remove impurities such as dyes or heavy metals from even highly polluted water in just minutes. As explained by Professor Zhang, “It works by binding the atoms of the dye or heavy metals to the ribbon, leaving behind usable water.

“This offers a number of benefits compared to the current method of using iron powder to treat wastewater. Firstly, using iron powder leaves you with a large amount of iron sludge that must be stored. Secondly, it is expensive to produce and can only be used once.

“In contrast, the iron-based metallic glass we have developed can be re-used up to 20 times, produces no waste iron sludge and can be produced as cheaply a few dollars per kilogram.”

Professor Zhang said the technology could have significant applications in the mining and textile industries, which produce “huge amounts of water that is contaminated with heavy metals and dyes respectively”.

“We have already had significant interest from companies in both China and Australia who are keen to work with us to develop this technology, including Ausino Drilling Services, whose clients include Rio Tinto and the Aluminium Corporation of China.”

Ausino CEO Dr Minlu Fu said he looks forward to collaborating with Professor Zhang, stating, “Laichang’s recent research using metallic glass as a catalyst for ultrafast water purification is very achievable in the industrial application.”

Professor Zhang’s research has been published in the journal Advanced Functional Materials.