Evaluating the treatment of heavy metals in acidic wastewater by activated carbon.

The study investigated the use of activated carbon (AC), produced from pinewood, to remove copper, zinc and iron from modified landfill leachates. South Africa faces an imminent water crisis, hence the need to see wastewater as an important source that must be treated and reused to combat water deficits in future. The use of AC as a soil amendment for the removal of heavy metals (HM) is not well researched. This study aimed to determine the ideal amount of AC (5%, 10%, 15% and 20% [w/w]) to add to soil using leaching columns for optimum HM adsorption. Modified acidic wastewater (pH > 2) was leached through soil columns packed with sandy loam soil and different amounts of AC (5%, 10%, 15% and 20% [w/w]). The results indicated that all the columns efficiently removed 94% copper, 80% zinc and 99% iron. Even a small amount (5% w/w) of AC was effective in removing HMs and can thus be considered as a possible cost-effective treatment option for acidic wastewater.