The CSIR has developed a new process to reclaim high-quality precipitated calcium carbonate (PCC) from calcium-rich industrial solid waste.
High-quality calcium carbonate is useful for various specialised industrial applications such as gastric acid treatment, tablet filling in pharmaceuticals, plastics, paint, adhesives and in pulp and papermaking.
This technology may offer a solution to acid mine water in Gauteng.
“We also foresee an increase in demand for calcium carbonate for treating acid mine drainage,” said biochemical engineer Dr Mlawule Mashego, who developed the technology with Jean Mulopo.
The research group is focused on recycling technologies that would make extraction of effluent cost-effective.
The method appears to be effective with streamed water, but is unlikely to be effective where groundwater is contaminated.
“Some utilities responsible for waste treatment and management are moving away from regulatory compliance toward increased economic incentives in the process of recognising the value of waste and wastewater as a resource.
“Such an approach includes the recovery of energy, nutrients, metals and other chemicals as part of the wastewater treatment process. We also look at further beneficiation of recovered by-products to enhance waste utilisation,” said Mashego.
The CSIR has filed a patent for the technology would could also be exported to developing countries where issues of water contamination affect local populations.