Waste & Resource Recovery

New zero-waste tech released for toxic acid waste treatment

Researchers at the University of Canterbury (UC) in New Zealand have created a sustainable technology that could revolutionise the galvanising industry and save the environment from toxic acid waste.

Associate professor of engineering Dr Aaron Marshall and chemical and process engineering master’s student Jonathan Ring have developed an award-winning, almost zero-waste global solution for treating waste acid from galvanising, the process of applying a protective zinc coating to steel or iron.

The inventive process, which recently won funding in the University’s annual Innovation Jumpstart content, enables 100kg of zinc and 150kg of iron per tonne of waste acid to be removed and recycled, instead of the current process which landfills this waste.

“The global potential is huge. The current approach of neutralisation and landfilling is simply not sustainable and has the potential for serious environmental impacts due to the toxicity of this waste,” Marshall said.

“We believe that our process could be expanded to include acid recovery, which would further reduce the operating costs of the overall galvanising process and almost completely eliminate waste disposal.”

When fully developed, the zero-waste process will have the ability to recover $350,000 of discarded zinc from Aotearoa New Zealand’s galvanising industry annually and could also lower disposal costs. Galvanised steel is used widely in the construction of roads, railways, other infrastructure, appliances and buildings.

“Globally, the market for the technology is huge, with estimates suggesting that the Chinese market alone is worth more than $120 million,” Marshall added.

As part of his Master’s degree, Ring has been investigating a wide-range of existing technologies, most of which are too expensive and complex to be viable in the galvanising industry. Together with Marshall, who is an expert in electrochemical engineering, they identified a gap in the market for a low-cost and reliable process.

The research won them $20,000 to transform their ideas and research into commercial reality, in UC’s annual Innovation Jumpstart competition.

“The prize allows us access to market analysis and to look at where we might get further funding,” Marshall said.

“These things are critical in moving the project from its early stages to the next level where we plan to scale-up and prove our technology under industrial conditions.”