Materials

Cheap metal ribbons strip pollutants from water in minutes

Laichang Zhang from Australia's Edith Cowan University has led the development of a new material that strips impurities from wastewater
Edith Cowan University
Laichang Zhang from Australia's Edith Cowan University has led the development of a new material that strips impurities from wastewater
Edith Cowan University

A breakthrough in the realm of wastewater treatment is promising to greatly hasten the process of removing pollutants, and do so at a fraction of the cost of existing approaches. Scientists in Australia have come up with the cheap alloy capable of stripping impurities from contaminated water, which could have great implications for industries such as textile production and mining.

The mining industry in particular is a place we have seen scientists look to improve through next-generation water treatment technologies. Mining operations produce massive amounts of wastewater packed with acids and heavy metals, while textile production results in water laden with dye pollution. Filters made from quartz fibers, reusable microbots and sun-activated nanoparticles are a few new technologies that might come to eat away at the problem.

But scientists at Australia's Edith Cowan University have a new solution they say can cleanse wastewater with a new degree of efficiency. The breakthrough centers on a fabrication method previously used by the team to develop metallic glasses with a disordered atomic structure that remove impurities from wastewater.

This technique was adapted to form what they call crystallized Fe-based ribbons, which are heated in a specific way to form a more ordered atomic structure. This enables electrons within it to move more freely and better bind with pollutants.

"By using a specific treatment, metallic glasses start to become a crystalline structure and there are grains generated inside," lead researcher Laichang Zhang explains to New Atlas. "The grains generated in the crystallized Fe-based ribbons tend to form numerous galvanic cells inside the material due to the potential difference, which facilitates the electron transferring inside grains and across grains.

"The fast electron transportation is usually what we desire in the wastewater treatment," Zhang continues. "A fast electron transportation from our materials to contaminants leads to an effective conversion of contaminants into harmless substances such as H2O, CO2, etc. That is to say, the faster electron transfers, the higher contaminant removal efficiency is."

According to the team's testing, the material is efficient enough to purify water contaminated by dyes, heavy metals and organic pollutants in minutes, which is much faster than existing methods. The team says it also produces no waste throughout the process and the same material was reused up to five times in testing. Notably, they say enough alloy to clean a ton of wastewater can be made for just AUD$15 (US$10).

From here the team is working with industry partners to lower the cost further and improve the material's efficiency, which could be achieved by tweaking the size of the grains.

The video below includes a demonstration of the material's water purifying capabilities, while the research was published in the journal Advanced Materials.

Source: Edith Cowan University

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4 comments
CarolynFarstrider
This is a very interesting idea, but will it scale (as the business pundits say)? A tonne of water is just a cubic metre; that's not much. And there surely cannot be 'no waste', as either the novel material has to be stripped of its contaminants prior to reuse, or the whole strip of material has to be disposed of? Look forward to hearing more.
notarichman
try it out on a polluted pond? make it 3D and maybe it will capture even more? imagine a form of steel wool. i see it takes energy to stir the water. would it work faster if the water was heated? fill the inside of a pipe with it and some way to pull it out and replace it... the polluted water might be clean when exiting.
ljaques
If the cleaned water can be reused by the facility which produced the contamination, this is truly great news. Anything which saves fresh water is a very good thing.
I wish them luck perfecting and implementing it.
Douglas Bennett Rogers
This should find immediate use in space, where weight equals cost.