In an effort to alleviate the burden of water contamination, Prof Patricks Voua Otomo, Associate Professor in the Department of Zoology and Entomology at the University of the Free State, is researching how ordinary oyster mushrooms could help tackle one of South Africa's most pressing environmental challenges: water contamination. The implications of this research extend far beyond South Africa's borders, offering a sustainable solution for global water treatment challenges
The Water Crisis: A Growing Concern
The numbers paint a concerning picture of South Africa's water treatment capabilities. According to the 2022 Green Drop Report, out of 850 wastewater systems across 90 municipalities, only 23 systems—less than 3%—qualified for Green Drop Certification. This statistic underscores the depth of the wastewater treatment crisis in South Africa and its implications for human and environmental health.
The challenge is particularly evident in the Qwaqwa region, where water contamination stems from two main sources: wastewater treatment plants and direct disposal of household waste into waterways. This has resulted in concerning levels of pharmaceutical contaminants in local rivers, including:
Biphenyl-4-ylacetic acid (an anti-inflammatory)
Efavirenz (an HIV medicine)
Carbamazepine (an epilepsy medicine)
Mycofiltration of ferric iron aqueous solution. (Credits: UFS)
Nature's Filter: The Power of Mycelia
Under the leadership of Prof Patricks Voua Otomo, Associate Professor in UFS's Department of Zoology and Entomology, researchers have developed a mycofiltration system using Pleurotus ostreatus (oyster mushroom). The research team's results are compelling: their mycofilter successfully removed up to 94% of iron (III) and 31% of imidacloprid from contaminated water samples.
The mycofiltration process works through adsorption, where molecules, ions, or particles from liquids or dissolved solids adhere to a surface. In this case, the contaminants (adsorbate) attach to the mushroom's mycelial network (adsorbent). This natural filtration mechanism shows promise for addressing various water contamination challenges.
Helisoma duryi freshwater snails exposed in non-mycofiltered ferric iron aqueous solution, mycofiltered ferric iron aqueous solution and tap water. (Credits: UFS)
From Laboratory to Implementation
The research, spearheaded by PhD candidate Sanele Mnkandla, is now moving toward practical applications. The team is currently:
Testing the technology using wastewater effluent in the Qwaqwa region
Exploring local applications in rainwater harvesting
Investigating methods to scale up the mycofilter for larger bodies of water
The duration of the filtration process varies based on several factors:
Size of the filter
Volume of water to be filtered
Target chemicals to be removed
Larger filters can process more water over extended periods
Smaller filters reach saturation more quickly
Processing time ranges from minutes to days
This research aligns with the United Nations Sustainable Development Goal 6, which aims to achieve universal access to safe and affordable drinking water by 2030. Target 6.3 specifically focuses on improving water quality by reducing pollution, eliminating dumping, and minimizing the release of hazardous chemicals.
The UFS team has published both a technical note and proof of concept for their mycofiltration system. Prof Voua Otomo confirms that mycofiltration represents a viable and affordable option for water remediation, with potential for wide-ranging applications across South Africa.