School of Chemistry & Physics

Left: Ms Lungile Hadebe celebrating her graduation and (right) working in the lab.

Chemical Desalination Master’s Applicable to the Circular Economy

A Master’s in Chemistry cum laude is the result of Ms Lungile Hadebe’s research on reclaiming potable water from brackish water using an innovative technology together with discarded coffee grounds to develop a potential material for use in water purification technology, contributing to a more sustainable society.

Hadebe utilised capacitive deionisation technology (CDI) for water purification, which removes salt ions or charged species from aqueous solutions using two oppositely charged electrodes. The performance of CDI relies on the structural and textural characteristics of the electrode materials, usually expensive and involving complicated synthesis methods, as well as being derived from non-renewable resources.

In her project, Hadebe used biowaste in the form of easily accessible and abundant waste coffee grounds to serve as the electrode material. The prepared carbon electrode was characterised using different techniques to investigate the properties of the material, and demonstrated its potential to be used in the CDI technology to replace expensive, non-renewable electrode materials.

In addition to addressing the scarcity of safe drinking water – Hadebe pointed out that only 0.26% of the earth’s 2.5% freshwater resources are suitable for human consumption, with South Africa’s rural areas particularly afflicted by dependence on unsuitable groundwater sources – she also hopes it will promote the circular economy and the use of waste as a resource.

‘CDI technology is convenient to utilise in rural areas for the reclamation of drinkable water since it requires less energy,’ she said.

Hadebe’s interest in chemistry was piqued when she realised that the discipline is not limited to the laboratory, but can be seen in soil’s interaction with water, fertiliser and seed to yield a crop.

‘If everything has an element of chemistry, then chemistry can be used to meet basic human needs such as food, health, clean water, air and soil,’ she said.

Having grown up lacking clean water and electricity, Hadebe is satisfied that her degree will help her to help communities, her country and the world at large.

Keen to pursue a career in research, Hadebe is now enrolled for doctoral studies on UKZN’s Westville campus, drawn to the Institution for its academic quality, learning environment, facilities and courses, and says she is grateful for the opportunity to pursue her studies at the University.

Despite the mental health challenges brought on by the isolation and disruption of the COVID-19 pandemic, as well as the fire damage sustained by the campus’s chemistry facilities in November 2021, she used her challenges to fuel her drive for success, and was able to attend a conference and publish a research article during her studies.

The article: Properties of porous carbon electrode material derived from biomass of coffee waste grounds for capacitive deionization won Hadebe first prize at an international conference on applied research and engineering.

‘My biggest accomplishment was to show that it is possible for a rural child from a disadvantaged background to excel at an international level, and receiving my master’s cum laude is validation,’ said Hadebe.

She thanked her supervisor Dr Bhekumuzi Gumbi not only for his supervisory support, but also for his coffee consumption that furnished her with the experimental materials she needed. She also thanked her industrial supervisor Dr Zamani Cele of the Council for Scientific and Industrial Research, and her funders, the Water Research Commission, the National Research Foundation Thuthuka grant awards, and GreenMatter. She also credited her laboratory colleagues, friends, and family, for their consistent support.

‘Most importantly, I thank God, because after all has been said and done, a person plans but God decides the course of our lives,’ said Hadebe.

Words: Christine Cuenod

Photographs: Sandile Ndlovu and supplied