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With a PhD from Tsinghua University in environmental science and engineering and years of industry and research experience, he is an expert in solving problems that use fundamental science to find practical solutions.

“I like to solve problems,” says A/Prof Zheng.

“My engineering experience enables me to identify the real problems, and my science knowledge helps me to find those novel solutions the water industry needs.”

A/Prof Zheng was awarded a highly competitive International Exchange Postdoctoral Fellowship in 2017 which enabled his move from China to Australia. Since then, he has initiated and managed a number of Australian research projects and competitive grants. His latest projects are focused on implementing more sustainable wastewater treatment technologies, mostly centred around utilising iron and iron solids within the treatment process.

Addressing inequity in regional Australia

In remote areas such as the Merredin region of Western Australia, wastewater is treated through traditional pond systems which produce a lot of odour, emit greenhouse gases and are limited in their effective removal of pollutants and pathogenic organisms. Usually, the most modern wastewater treatment technologies are not a feasible solution in remote communities due to the ongoing resources required for their operation and maintenance.

A/Prof Zheng is looking at other options, specifically upgrading the existing pond systems to make them more fit-for-purpose.

“We are exploring the introduction of iron salts to pre-treat the water through a solar system before it enters these pond systems,” says A/Prof Zheng.

“We’re working closely with Western Australia’s Water Corporation, which services 109 ponds state-wide, to develop a ‘smart pond process’ and deliver a technology that enables water utilities to produce the required iron salts on-site to meet demand.”

The use of iron salts is a new concept, leveraging a recent breakthrough which found that the oxidation of iron plates with electricity generates electrochemical iron (e-iron) - a viable alternative to commercial iron salts.[1]

A/Prof Zheng and his colleagues are first developing a lab-scale concept to test the technology before pursuing a pilot-scale demonstration. It is expected that the technology will reduce the inequity of wastewater services in regional Australia and provide significant social and health benefits to Australian Indigenous communities.

Reducing harmful greenhouse gas emissions

A/Prof Zheng is also leading a second project, this one exploring how to eliminate the greenhouse gas emissions produced through the urban wastewater treatment process. In partnership with Water Corporation and Melbourne Water, the 5-year ARC Linkage Project is helping utilities achieve their net-zero goals by investigating new ‘green’ methods for nitrogen removal.

For 100 years, nitrogen has been removed using ‘nitrification’, and there have been very few viable alternatives available. A/Prof Zheng and his team are investigating a new microbial process that uses iron instead—drastically reducing nitrous oxide emissions to near zero.

While iron is commonly used within drinking water treatment plants as a coagulant, and also used for sulphide control and phosphorous in sewage transfer and treatment systems —it has never been used for nitrogen management.

A/Prof Zheng says that the potential benefits of using the iron technology not only reduce nitrous oxide emissions, but also help to maximise energy efficiency in other ways.

“The same process we are exploring for nitrogen removal also enables the conversion of more wastewater organics into biogas,” says A/Prof Zheng.

“Utilising this biogas has the potential to reduce the chemical and energy consumption of wastewater treatment plants by up to 80%.”

With Water Corporation and Melbourne Water jointly serving about a quarter of the country's population—this project promises substantial benefits for Australian communities.

Making an impact

While A/Prof Zheng has only recently joined UNSW, he is an important member of the water community. His research group Green Environmental Technologies of Sustainability (GetSus) is fast becoming known for its innovations and applications in biochemical processes for net-zero emissions in the water sector.

A/Prof Zheng sums up his goals for now and the future in a few simple words:

“Let's work together towards a sustainable, low-carbon society.”

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