Nano humus is able to be extracted from coal mine deposits, crushed into a fine, black powder and used to extract heavy metals from contaminated environments.

Yihan Zhao conducted the research which saw nano humus extract cadmium – a toxic heavy metal produced in many mining contexts – from water.

Zhao found the nano humus acts like a sponge, soaking up 90 per cent of the cadmium in 15 minutes and 93 per cent in 24 hours.

“It’s rapid, safe and effective,” Zhao said, with the research earning her a PhD in land reclamation and remediation.

Zhao’s project supervisor Anne Naeth predicted the process could be commonplace in mining rehabilitation within the next five years.

“The fact that we can use a waste material to reclaim an area that produces it is exciting,” Naeth said.

On top of this low-cost, efficient method for remediation, the nano humus could be used to replace some materials which are used to replace the contaminated soil, such as manure and straw.

“The huge amounts of these standard materials we need to apply has always been an issue for their use in land reclamation,” Zhao said.

“Using nano humus reduces the amount of material we need and makes it much easier to transport and apply.”

The findings of Zhao’s research could be especially important to developing countries that can’t easily rehabilitate their lands.

“Using nano humus to treat their contaminated land and water means reduced health risks and makes their land available for agricultural production and food security,” Zhao said.

“The research also contributes to developing long-term solutions to the environmental concerns of industries globally.”