The Mangosuthu University of Technology (MUT) academics and their counterparts from the Council for Geosciences have discovered high concentrations of six potentially harmful elements (PHE) in the Krugersdorp Game Reserve.
The academics conducted a study to determine the levels of various elements in toxic wastewater and acid mine drainage (AMD) in the Krugersdorp mining area in Gauteng.
PHEs are elements that are toxic at certain concentrations to one or more species, but in many cases are also essential nutrients at lower concentrations.
The study found the area’s water bodies to have concentrations of silver, arsenic, cobalt, chromium, manganese and vanadium, which were higher than the amounts permissible by the World Health Organisation (WHO).
“All these values are in excess of the minimum alveolar concentration levels set by the WHO or other accredited institutions for groundwater or drinking water. These results raise a safety concern, as many PHEs are required to be within the recommended limits,” the study emphasised.
The presence of silver concentration in the water was not surprising given that the element is a by-product of gold refining and the area is home to two large-scale gold mining outfits – Mintails Mogale Gold and Rand Uranium.
“In terms of producing large volumes of wastewater, the South African mining industry is notorious for generating AMD, which renders wastewater toxic and unusable.
“Aside from the fact that AMD contaminates surface and underground water, even decades after mining operations ceased, the cost of treating it is high, and treatment is often required when mining operations have stopped,” the academics said.
The study 'Determination of Potentially Harmful Element (PHE) Distribution in water bodies in Krugersdorp, a mining city in the West Rand, Gauteng Province, South Africa' was published in the Minerals journal.