Water, Sewage & Effluent May-June 2018 | Page 26

There’s money in muck! Rather than focusing on the problems that raw sewage could (and does) create, why not investigate how to use this endless resource profitably? By Mike Muller With land applications, biosolid waste can be applied at specific, varied rates that will meet crop nutrient requirements. W astewater management in South Africa is a national scandal. We know that because the previous Minister stopped publishing the Green Drop reports on wastewater treatment because they were just too embarrassing. There is a dire need for a new approach to avoid a situation in which all South Africa’s rivers turn as green as the Hartbeespoort Dam usually is. Waste should drive the wastewater treatment process. We are always told that there is wealth to be made from waste. Too often though, that is just propaganda. I recall in the early days of the 24 debate over how to deal with the acid mine drainage problem in the Witwatersrand (a problem that, I think, is exaggerated), the mines came up with a novel solution: If government were to join them in treating the waste, they would be able to sell the by-products and the process would pay for itself. Their enthusiasm to sell the stuff was understandable. In one of my other lives, I went down the old Grootvlei Mine on the East Rand to the chamber where the pumping equipment was running hard to keep the mine dry. The huge cavern was half full of what looked like bright red Water Sewage & Effluent May/June 2018 sandstone. As the water emerged from the rock into the sump from which it was pumped, the dissolved iron immediately reacted with the iron to form a fine iron oxide powder. It was hell to manage — the trick was not to allow the water to come in contact with air until it was safely out of the shaft. But the miners had a bright idea. They could sell that iron oxide and make a profit. And they duly came with evidence that there was a profitable market for high-grade iron powder, for use as a pigment in paints and other products. The price was interesting, but they neglected to tell us how small the market was — certainly not big