Professor finalist in awards for work on cleaning ‘acid’ water
UNIVERSITY of the Western Cape (UWC) Professor Leslie Petrik is flying the flag high for her institution and the province, being named a finalist in the Department of Trade and Industry’s technology awards for her work on cleaning water affected by acid rain drainage.
Petrik, who was also recognised for her efforts in training the next generation of researchers, and who works in the university’s natural science department, has been named a finalist in the human resource development category for this work.
Although she took the run- ner-up place behind Professor Jannie Maree from the Tshwane University of Technology, Petrik won wide praise.
Acid rain drainage, a byproduct of mining, made headlines recently, as the debate between water security in South Africa and the economic benefits of the mining sector rages.
Acid rain drainage forms through a chemical reaction when oxygen and air come into contact with pyrite, also known as iron sulphide, a rock type associated with coal and gold mines.
This reaction between oxygen, water and pyrite forms sulphuric acid and dissolves these rocks, forming acid mine drainage. It is a major concern because it poisons any water it comes into contact with.
Although acid rain drainage effects are centred on the gold fields and coal mines of Gauteng, North West, Mpumalanga and the Free State, solutions are being worked towards at UWC.
Petrik and her research team, who have been working with the department for the past nine years, said although it may not affect the Western Cape directly, “it is a South African challenge, as we are all South Africans”.
“We want to contribute towards finding solutions.”
They have been using fly ash to purify water.
“Solid organic components from the soil are absorbed into the coal as it is formed. Because we use a lower-grade coal in South Africa, with only about 60 percent of coal content, the remaining waste left behind after burning the coal are the inorganic components,” Petrik said.
“The huge amount of waste ash left after burning the coal is classified as two types: bottom ash – which is the larger, heavier particles – and fly ash, which is light and floats into the sky.
“Fly ash contains a large amount of alkaline substances which increase the pH of the acid mine drainage to counter the acid- ity in the water.
“If not for our process, the fly ash may be piled on to slag heaps and never used again,” Petrik said.
The process removes most harmful metals from the water within an hour, leaving the recovered water suitable for agricultural use.
If it was polished to remove any remaining hazards, it would also be safe for drinking.
Petrik said the fly ash could also be used to make zeolytes, which can be used in the production of chemicals, or for separating gases or capturing and storing carbon dioxide.
She and her team hoped to continue refining the fly ash process with a 1 000-litre pilot trial at a contaminated site in Krugersdorp in March next year.
Lionel October, the department’s director general, applauded researchers like Petrik for their efforts in taking technology forward.
“The purpose of technology awards is to raise awareness of the benefits of using technology to improve the competitiveness of enterprises,” October said.
“The awards recognise individuals and organisations (working) towards technology development and innovation in South Africa.
“They are also aimed at inspiring and encouraging creativity and technological inno- vativeness among business people, by rewarding those who make use of technology to advance their businesses,” he said.
AQUAWOMAN: Leslie Petrik