Focus on the three Rs – remediation, reuse and recovery
A novel project using membranes and nanotechnology to produce clean water, near-zero emissions and one of the world’s most prized resources, lithium, will benefit people in Australia and India. Environmental engineer Dr Gayathri Naidu is leading the international research effort.
What are your areas of expertise?
My core research is dedicated to exploring the three Rs in seawater and wastewater – that is remediation, reuse and recovery. I develop nanomaterials and membranes to drive the global water industry towards recovering valuable resources such as lithium and rare earth elements.
I have come to this part of my career via bachelor’s and master’s degrees at the University of Malaya Kuala Lumpur and Imperial College London, respectively; I obtained my PhD in Environmental Engineering from UTS.
Tell us about your Australia-India Strategic Research Fund project. How did that come about?
In Australia and India, wastewater or brine – for example, seawater/brackish water, textile dye, tannery effluent and mining industry brine – is a major problem. It must be treated before it can be released into waterways, to minimise environmental harms. Due to the wide spectrum of industry pollutants, brine treatment is technically challenging and energy intensive, creating significant carbon emissions. Moreover, the conventional approach of treat and discharge is unsustainable.
A better approach is to maximise water production while minimising discharge to the environment, known as near-zero liquid discharge, and near-zero carbon emissions. Our project will adopt this approach while recovering valuable resources to offset the cost of brine treatment.
When I was introduced to the Periodic Table of Elements, I was so inspired that Dmitri Mendeleev put it together in the 18th century and it is still relevant today.
Dr Gayathri Naidu
What excites you about this work?
This project will take steps to increase the commercial appeal of solar integrated membrane processes through competitive off-grid technology for treating brine and recovering valuable resources. The nature of this project (with membrane technology and artificial intelligence/data learning experts) will enable us to develop a dedicated energy-economic model of brine treatment activities. We will be able to provide a tool for decision makers to evaluate alternative water treatment technologies for reducing carbon emissions.
The other exciting aspect is the opportunity to work with a fantastic research team in Australia – Professor Michael Blumenstein leading the data-learning component, and membrane technology mentors Professor Hokyong Shon and Professor Saravanamuthu Vigneswaran. At the same time, I will collaborate with renowned researchers in India – Associate Professor Jaichander Swaminathan, from the Indian Institute of Technology, and Professor Umapada Pal, from the Indian Statistical Institute.
Why is this work important? Who will it benefit?
The Australia-India Strategic Research Fund is financed by the Australian Department of Industry, Innovation and Science to strengthen strategic alliances and research between Australia and India.
Australia and India are ideal locations for the proposed project because both have regions that have experienced decreased rainfall, and both have areas with high solar irradiance. People living in remote parts of Australia and India are suffering from shortages of fresh water through drought. Small-scale solar-powered membrane technology could be used in a niche application.
On an economic front, the successful outcomes of this project will bolster the renewable energy sector as well as immediate beneficiaries in the water industry and through commercialising lithium recovery from brine.
Why is the potential for lithium recovery so important?
Lithium is an increasingly valuable commodity due to the battery market. Today, Australia meets lithium demand by mining non-renewable hard rock, a carbon-intensive activity due to its high chemical contaminations and complex hydrometallurgical process.
A sustainable alternative is to source lithium from seawater and brine. However, extracting lithium from brine is challenging because other ions – sodium, magnesium, calcium – are present in much higher concentrations than lithium.
For my ARC research fellowship, I am working to develop nanomaterials to extract lithium while recovering fresh water electrochemically. The system would produce additional fresh water from brine, attaining near-zero liquid discharge, and the sale of lithium can offset desalination treatment costs.
Sometimes it’s the simplest research ideas, inspired from our day-to-day activities, that translate into practical research outcomes. Unlearn complex theories – that is the advice I give my students.
Dr Gayathri Naidu
What attracted you to your field? Who or what has inspired you?
The first time I was introduced to the Periodic Table of Elements, I was so inspired by the fact that Dmitri Mendeleev put it together in the 18th century and it is still relevant today. This sparked my interest in chemistry and resource recovery.
While I am recovering valuable resources from various water sources that are well-identified elements from the table of elements, perchance I hope to recover an unidentified element (and I will name it after myself).
While I am passionate about chemical science, engineering provided me with the platform to translate fundamental scientific knowledge into industrial applications to solve global water challenges. This is what attracted me to the field of environmental engineering
What has surprised you about your research experience?
That sometimes it’s the simplest research ideas, inspired from our day-to-day activities, that translate into practical research outcomes. Unlearn complex theories – that is the advice I give my students
In research, we try to chemically synthesise nanomaterials and polymer membranes by mimicking ideas from nature, be it our skin cells or plant materials. But in all honesty, we can never come close to these natural wonders. It intrigues me and makes me appreciate the perfection of nature and the universe. As humans, not only are we fallible, we mistreat these natural wonders.
STAYING THE COURSE
What has been most challenging about the coronavirus pandemic? Have you found any silver linings in this period?
That I started my first project (ARC DECRA) as a lead investigator in 2020, right at the start of COVID. I managed to secure good PhD students to work on my project, but as the international borders remain closed due to COVID, they have not yet arrived at UTS.
At the beginning of COVID, with research slowing down, labs shutting and no international research travel, I never thought I would find a silver lining. Having said that, the quiet time inspired me to think of a new research idea on developing membranes embedded with nanomaterial for solar water evaporation, which led to an international fellowship.
And after all these years in research, for this first time my herb garden is growing gloriously as I have time to care for my plants while I work from home!
Dr Gayathri Danasamy Naidu is a senior lecturer and ARC DECRA Fellow at the Centre for Technology in Water and Wastewater (CTWW) in the UTS School of Civil and Environmental Engineering.
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