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09 December 2022 | Story Leonie Bolleurs | Photo Leonie Bolleurs
Dr Refilwe Mogale
Dr Refilwe Mogale received her PhD in Chemistry. She is fascinated by the ability of chemistry and science in general to solve some of the world’s most pressing issues, such as water scarcity.

“Chemistry chose me,” says Dr Refilwe Mogale, who wanted to enrol for Psychology years ago when she decided to study at the University of the Free State (UFS). 

“On the day of registration, however, as I was standing in the queue, something inside me said this was not the right choice for me. Ultimately, I chose my second option, which was a BSc degree majoring in biology, physics, and chemistry.”

“Once I started the BSc programme, I gravitated towards chemistry, and as difficult as it was juggling classes and six-hour practical sessions, I loved it. I am fascinated by the ability of chemistry and science in general to solve some of the world’s most pressing issues, such as water scarcity, alternative generation, access to antibacterial hygiene products, as well as novel strategies to cure diseases, among many other things.”

The UFS awarded Dr Mogale a PhD in Chemistry on 9 December 2022.

Addressing a global challenge

Being passionate about applied chemistry – where scientific research can be used to create products to address everyday problems – Dr Mogale focused her thesis on Aluminium- and Zirconium-based metal organic frameworks with azobenzene and stilbene dicarboxylate ligands for use in wastewater treatment. 

She has also published multiple articles on topics of environmental chemistry and wastewater management in international journals. 

Dr Mogale is of the opinion that water pollution by financially lucrative industries and access to clean drinkable water is one of our planet’s most challenging environmental and health issues. “The waste generated by some of the industries that contribute heavily to our country’s economy, such as the textile, agricultural, and medical industries, may end up in the limited drinking water resources we have. I chose my research topic because I wanted to positively contribute to this global challenge,” she says.

“My research was based on making highly porous metal-organic frameworks (MOF) to be used in the wastewater treatment technique called adsorption,” explains Dr Mogale, describing MOFs as “really cool three-dimensional ‘sponges’ that can suck up very high amounts of gases and pollutants, trapping them in their pores. These trapped materials can later be released from the pores to be re-used when MOFs are exposed to certain stimuli.”

She continues, “Low cost and simplicity make this method attractive for industrial use. Considering our current energy crisis, other methods are not ideal, since they require large amounts of energy.” 

Focused on developing highly effective adsorbent for wastewater purification systems, Dr Mogale synthesised a novel MOF with one of the highest adsorption capacities compared to existing counterparts.

According to her, should MOFs with their incredibly high surface areas – which allow them to absorb more waste than their existing counterparts – be implemented in wastewater purification systems, they would be able to address the environmental issue of water pollution and the health issue of access to drinkable water.

Tackling everyday societal issues

She is currently doing a postdoctoral fellowship in the UFS Department of Chemistry – to broaden her knowledge in chemistry beyond MOFs. Her plans are, however, to transition to industry and ultimately entrepreneurship, where she will be able to develop scientific products that can tackle everyday societal issues. 

Dr Mogale dreams of adding value to society by practically contributing to the water crisis issue through the development of low-cost water generation and purification products.

News Archive

Research helps farmers save with irrigation
2017-02-15

Description: Irrigation research Tags: Irrigation research

Marcill Venter, lecturer in the Department of
Agricultural Economics at the University of the
Free State, has developed the mathematical
programming system, Soil Water Irrigation
Planning and Energy Management in order to
determine irrigation pump hours.
Photo: Rulanzen Martin

Her advice to farmers is that they should make sure they are aware of the total cost (investment and operating costs) of an irrigation system. In most cases the investment cost is low, but the operating cost over the lifetime of the system is high.

“It is very important to have a look at the total cost and to install the most economic system,” says Marcill Venter, lecturer at the University of the Free State (UFS), who has done research on the economic sustainability of water-pipe systems.

Irrigation systems important components for farming
This research comes at a time when many farmers are relying on their irrigation systems due to persistent drought and low rainfall during 2016. South Africa has also experienced an abnormal increase in electricity tariffs in recent years. Due to tariff increases which threaten the future profitability of irrigation producers, the Water Research Commission (WRC) has launched and financed a project on the sustainable management of irrigation farming systems. “I had the opportunity to work on the project as a researcher,” says Venter.

The heart of every irrigation system is the water pipes that bring life to crops and livestock, and this is what Venter’s research is about. “Water pipes are part of the whole design of irrigation systems. The design of the system impact certain factors which determine the investment and operating costs,” she says.

Mathematical system to help farmers
Venter and Professor Bennie Grové, also from the Department of Agricultural Economics at the UFS, designed the Soil Water Irrigation Planning and Energy Management (SWIP-E) programming model as part of the WRC’s project, as well as for her master’s degree. “The model determines irrigation pump hours through a daily groundwater budget, while also taking into account the time-of-use electricity tariff structure and change in kilowatt requirements arising from the main-line design,” says Venter. The model is a non-linear programming model programmed in General Algebraic Modeling System (GAMS).

Design of irrigation system important for sustainability

The main outcome of the study is that the time-of-use electricity tariff structure (Ruraflex) is always more profitable than the flat-rate structure (Landrate). The interaction between the management and design of a system is crucial, as it determines the investment and operating costs. Irrigation designers should take the investment and operating cost of a system into account during the design process. The standards set by the South African Irrigation Institute (SAII) should also be controlled and revised.

Water-pipe thickness plays major role in cost cuts
There is interaction between water-pipe thickness, investment and operating costs. When thinner water pipes are installed, it increases the friction in the system as well as the kilowatt usage. A high kilowatt increases the operating cost, but the use of thinner water pipes lowers the investment cost. Thicker water pipes therefore lower the friction and the kilowatt requirements, which leads to lower operating costs, but thicker pipes have a higher investment cost. “It is thus crucial to look at the total cost (operating and investment cost) when investing in a new system. Farmers should invest in the system with the lowest total cost,” says Venter.

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