Africa: 'Biochar' Could Help Clean Polluted Water

Africa: 'Biochar' Could Help Clean Polluted Water

A type of charcoal made from eucalyptus trees could provide the solution to South Africa's polluted water.

A University of Stellenbosch academic is developing a low-cost, low-tech water purification system with the charcoal, which will remove organic compounds from waste water in urban areas, the DST-NRF Centre of Excellence in Food Security said on Monday.

The charcoal, called biochar, could remove organic, some inorganic, and microbiological contaminants from water.

Professor Gunnar Sigge and collaborators at the Universities of Venda and Pretoria developed the purification system.

Sigge and colleagues tested different types of biochar made of pine and eucalyptus to maximise the amount of pollutants removed from the water. Of the two tree species tested, eucalyptus provided the best biochar.

"This filtration method could benefit subsistence farmers. And, with further development, eucalyptus biochar could be used to remove organic pollutants from wastewaters produced by wineries and the food industry."

Improving the quality of drinking and irrigation water by lowering the microbiological hazards and food safety risks would be beneficial to people's health and the environment.

Adding used biochar to compost would benefit soil health and possibly result in increased crop yields, he said.

Since the organic compounds remained attached to the biochar, they could be recycled to create new organic products.

"Therefore not only is biochar filtration a low-cost, low-tech way to remove organic pollutants from water, but it is also wastewater treatment that is both renewable and sustainable."

The Department of Science and Technology/National Research Foundation Centre of Excellence in Food Security is jointly hosted by the University of the Western Cape and the University of Pretoria.