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Turning waste into value through chemistry

25 August 2025 | Story Martinette Brits | Photo Stephen Collett

Prof Elizabeth Erasmus during her inaugural lecture, Molecules of Change: Chemistry for a Better Tomorrow, on 20 August, highlighting how innovative chemistry can turn waste into value and promote sustainable solutions.

With climate change, resource scarcity, and environmental pollution among the most pressing challenges of our time, Prof Elizabeth (Lizette) Erasmus used her inaugural lecture on Wednesday, 20 August to show how chemistry can provide powerful, practical answers. In her lecture, Molecules of Change: Chemistry for a Better Tomorrow, she traced her journey from fundamental research to pioneering innovations that turn waste into value, protect ecosystems, and improve food security.

During her talk, Prof Erasmus – Researcher in the Department of Chemistry – recalled a moment in 2018 that reshaped her career trajectory. While preparing a Sasol research grant on copper oxide nanoparticles, an entrepreneur assisting with the proposal posed a deceptively simple challenge: “So what?” “Although upsetting at first, those two words completely reshaped my outlook,” she explained. “They inspired my journey from purely academic chemistry towards more applied, impactful research – with the mission of not only advancing science, but of also improving society and the environment.”

From fundamental science to global solutions

Prof Erasmus began her career in organometallic chemistry, preparing and characterising complex molecules to understand their reactivity and physical properties. Later, her focus shifted to heterogeneous catalysis, where she explored nanomaterials and surface chemistry.

Her research has since evolved towards developing sustainable technologies that address urgent global challenges. One example is agricultural innovation: using green solvents to extract cellulose from wattle tree bark to create biodegradable superabsorbent polymers. “Unlike the polyacrylates in baby diapers, these SAPs degrade into nutrients for soil microbes and plants,” she explained. “By loading them with fertiliser, we develop slow-release, water-retaining materials that improve agricultural sustainability.”

Other projects include producing biochar to restore degraded soils, creating natural growth enhancers such as wood vinegar, and designing an ‘ultimate fertiliser’ that combines these products for long-term soil health. Her group also works on environmental remediation, developing hydrophobic sponges to absorb oil spills, repurposing building waste to clean polluted water, and using innovative chemistry to convert carbon dioxide into valuable products.

“We are even looking at one of the fastest-growing waste streams: e-waste,” Prof Erasmus noted. “With more gold per ton than natural ore, e-waste represents both a challenge and an opportunity. By developing porous absorbent materials, we can selectively capture and reduce gold ions directly to metallic gold – recovering a precious resource from waste.”

She concluded by crediting her team and collaborators: “This, however, is only the tip of the iceberg. The bulk of the work lies beneath the surface, carried out by dedicated students, collaborators, mentors, colleagues, friends, and family. I owe them my deepest gratitude, for they are the ones who truly sustain this journey of transforming chemistry into solutions for a better world.”

About Prof Erasmus

Prof Elizabeth (Lizette) Erasmus obtained all her degrees at the University of the Free State: a BSc (2001), BSc Honours in Chemistry (2002), MSc in Chemistry (2003), and a PhD in Chemistry (2005). She has published more than 80 research papers, holds an H-index of 21, and has extensive experience in supervising MSc and PhD students.

After serving as a senior researcher at the CSIR, she returned to academia at the UFS, where her international collaborations in the Netherlands and at UC Davis broadened her focus from organometallic chemistry to heterogeneous catalysis and nanochemistry. Her expertise spans organometallic chemistry, electrochemistry, surface characterisation, and nanomaterials.

News Archive

Nanotechnology breakthrough at UFS

2010-08-19

Ph.D students, Chantel Swart and Ntsoaki Leeuw

Scientists at the University of the Free State (UFS) made an important breakthrough in the use of nanotechnology in medical and biological research. The UFS team’s research has been accepted for publication by the internationally accredited Canadian Journal of Microbiology.

The UFS study dissected yeast cells exposed to over-used cooking oil by peeling microscopically thin layers off the yeast cells through the use of nanotechnology.

The yeast cells were enlarged thousands of times to study what was going on inside the cells, whilst at the same time establishing the chemical elements the cells are composed of. This was done by making microscopically small surgical incisions into the cell walls.

This groundbreaking research opens up a host of new uses for nanotechnology, as it was the first study ever in which biological cells were surgically manipulated and at the same time elemental analysis performed through nanotechnology. According to Prof. Lodewyk Kock, head of the Division Lipid Biotechnology at the UFS, the study has far reaching implications for biological and medical research.

The research was the result of collaboration between the Department of Microbial, Biochemical and Food Biotechnology, the Department of Physics (under the leadership of Prof. Hendrik Swart) and the Centre for Microscopy (under the leadership of Prof.Pieter van Wyk).

Two Ph.D. students, Chantel Swart and Ntsoaki Leeuw, overseen by professors Kock and Van Wyk, managed to successfully prepare yeast that was exposed to over-used cooking oil (used for deep frying of food) for this first ever method of nanotechnological research.

According to Prof. Kock, a single yeast cell is approximately 5 micrometres long. “A micrometre is one millionth of a metre – in laymen’s terms, even less than the diameter of a single hair – and completely invisible to the human eye.”

Through the use of nanotechnology, the chemical composition of the surface of the yeast cells could be established by making a surgical incision into the surface. The cells could be peeled off in layers of approximately three (3) nanometres at a time to establish the effect of the oil on the yeast cell’s composition. A nanometre is one thousandth of a micrometre.

Each cell was enlarged by between 40 000 and 50 000 times. This was done by using the Department of Physics’ PHI700 Scanning Auger Nanoprobe linked to a Scanning Electron Microscope and Argon-etching. Under the guidance of Prof. Swart, Mss. Swart en Leeuw could dissect the surfaces of yeast cells exposed to over-used cooking oil.

The study noted wart like outgrowths - some only a few nanometres in diameter – on the cell surfaces. Research concluded that these outgrowths were caused by the oil. The exposure to the oil also drastically hampered the growth of the yeast cells. (See figure 1)

Researchers worldwide have warned about the over-usage of cooking oil for deep frying of food, as it can be linked to the cause of diseases like cancer. The over-usage of cooking oil in the preparation of food is therefore strictly regulated by laws worldwide.

The UFS-research doesn’t only show that over-used cooking oil is harmful to micro-organisms like yeast, but also suggests how nanotechnology can be used in biological and medical research on, amongst others, cancer cells.

Figure 1. Yeast cells exposed to over-used cooking oil. Wart like protuberances/ outgrowths (WP) is clearly visible on the surfaces of the elongated yeast cells. With the use of nanotechnology, it is possible to peel off the warts – some with a diameter of only a few nanometres – in layers only a few nanometres thick. At the same time, the 3D-structure of the warts as well as its chemical composition can be established.

Media Release
Issued by: Mangaliso Radebe
Assistant Director: Media Liaison
Tel: 051 401 2828
Cell: 078 460 3320
E-mail: radebemt@ufs.ac.za
18 August 2010

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