Wastewater 'cleans itself' with new technology

A new wastewater treatment technology has been used for the first time in a commercial setting. The Virtual Curtain technology has been developed as a cost-effective method for treating wastewater and reducing the amount of sludge, which is created as a result of dealing with wastewater, by up to 90 per cent. 

The Virtual Curtain makes use of hydrotalcites, which are layered crystal structures formed of aluminium, carbonates and magnesium. They function by trapping impurities within themselves, effectively meaning that wastewater is able to clean itself. The technology chemically manipulates these elements that occur naturally in wastewater, cleaning the water and raising its PH level.

The technology has been used for the first time in Queensland, Australia, to treat wastewater at a mine. It successfully removed metal contaminants from the wastewater, resulting in the equivalent of around 20 Olympic swimming pools of rainwater-quality water being discharged. 

Developed by a Commonwealth Scientific and Industrial Research Organisation (CSIRO) team led by Dr Grant Douglas, the Virtual Curtain also reduces the amount of semi-solid by-product created when treating wastewater. According to Dr Douglas, the amount of sludge the new technology creates is a small fraction of the amount that conventional lime-based treatment does. This means that mine wastewater can be treated in a way that has less impact on the environment.

As well as being beneficial for reducing environmental impact, the Virtual Curtain is also a cost-effective method of treatment for the mining industry, which generates millions tonnes of wastewater every year. Dr Douglas said that it results in a material that has a high metal value, which can then be reprocessed. This will help to offset the costs of treatment and improve the recovery rate of miners.

"If required, the treated water can be purified much more efficiently via reverse osmosis and either released to the environment or recycled back into the plant, so it has huge benefits for mining operators in arid regions such as Australia and Chile," said Dr Douglas.

"It is a more efficient and economic way to treat wastewater and is enabling the global mining industry to reduce its environmental footprint and extract wealth from waste."