Bananas! A versatile, tasty and accessible power fruit, packed with vitamins and good for blood sugar, digestive health, the heart and excellent in purifying water. Prof Jeanet Conradie, Research Fellow in the Department of Chemistry at the University of the Free State (UFS), and her team are researching the use of banana peel, amongst other natural materials, as absorbents for water purification.
The main aim of the UN Sustainable Development Goals (SDGs) Goal 6 is to ensure the availability and sustainable management of water and sanitation for all. The drastic reduction of pollution of freshwater is a prerequisite to achieve this goal. Accessible, clean and safe drinking water is critical for health, societal development and for all life. Approximately 70% of the Earth is covered by water, with the oceans holding about 97% of this water, and 3% as terrestrial freshwater. Most of this freshwater is locked in glaciers and groundwater.
Human health and development are particularly dependent on accessibility and availability of clean freshwater. This precious resource is under severe pressure from all corners, including overuse, climate change and industrial pollution. According to the United Nations Environment Programme (UNEP), approximately 1.9 billion people live in potentially severely water-scarce areas and by 2050, this figure could increase to 3 billion people. A major concern of the UNEP is that many freshwater sources are drying up or becoming more polluted, thus threatening the lives and livelihoods of communities, potentially deepening poverty in societies.
According to Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), a possible major cause of freshwater pollution could be attributed to the fact that up to 400 million tons of heavy metals, solvents, toxic sludge and other industrial wastes are released annually into the world’s waters. These pollutants also include heavy metals, radioactive substances, dyes, pesticides, pharmaceuticals, chiral chemicals as well as oil contaminants.
In this context, Prof Conradie focuses on water purification and environmental remediation. In collaboration with research teams in Cameroon and Nigeria, Prof Conradie is involved in projects that explore the use of natural materials — such as poplar leaves, banana peels, and coconut shells — as absorbents for water purification. Her research group performs in-depth material chemical characterisation using techniques such as Brunauer–Emmett–Teller (BET), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX), Powder X-ray Diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FTIR), thereby enabling better understanding of the properties of these compounds and subsequent publication of the research in leading scientific journals. Additionally, her group is developing novel ligands specifically designed to extract heavy metals from contaminated water, further contributing to solutions for environmental sustainability.
The overarching aim of Prof Conradie’s research is to contribute meaningfully to scientific advancement with real-world applications — specifically in the areas of sustainable energy, clean water, and improved medical treatments. She maintains active collaborations with research groups at local, national, and especially international levels to sustain momentum in these diverse fields.
Prof Conradie’s research has yielded over 460 publications in high-impact international journals on this and related topics. In one of her articles: Banana peel as a biosorbent for the decontamination of water pollutants. A review, published in Environmental Chemistry Letters 18, 1085–1112 (2020), the research looked at the viability of natural banana peel for water decontamination, in order to help advance its commercialisation. Banana peel has received particular interest as a viable biosorbent and alternative to the more expensive and complicated removal techniques, such as filtration, solvent extraction, coagulation, sedimentation, membrane separation, evaporation, reverse osmosis, electrocoagulation, advanced oxidation, skimming, chelation, reduction, photo-catalysis, dispersion, use of solidifiers, nanofiltration and irradiation, to name a few.
Other biosorbents such as cassava waste, rice husk, potato peel, corn cob, maize leaf, microbial biomass, cocoa pod, groundnut husk, sugarcane bagasse, orange peel, oil palm waste, and coconut husk have been tested. However, banana peel waste is of particular interest because it is widely grown, and the peel waste is readily available.
While the research showed the efficacy of banana peel as an effective biosorbent, the potential for commercial application is limited due to costs and requirement of skilled personnel and equipment.
Prof Conradie’s other research focuses on cleaner and sustainable energy. Prof Conradie’s group conducts extensive experimental and theoretical research on the electrochemical and photophysical properties of both novel and known molecules such as various transition metal complexes of b-diketones, polypyridines and hydroxybenzophenones. She has also collaborated with the Ghosh Laboratory at the University of Tromsø (UiT) in Norway for over 25 years. This partnership focuses on the study of porphyrin analogues with applications in cancer therapy, diagnostics, and renewable energy. These projects combine experimental and theoretical approaches to understand molecular properties at a fundamental level, enhancing both the scientific knowledge base and its practical applications. The collaboration also extends to partners in the US and India, fostering global scientific exchange.
Looking ahead, Prof Conradie plans to continue her research — primarily in computational chemistry.
