USING NATURE AS A FILTER INZAMBIA

A reed bed and dosing pond are reducing the low pH and high nitrate levels in plant effluent exiting AEL Zambia’s operations. After passing through the reed bed, the effluent is transferred to the dosing pond, where it’s tested. Lime is added manually to increase alkalinity prior to discharge beyond the site’s boundries.

A reed bed is a non-invasive filtration method for the natural reduction or removal of nitrates in effluent and/ or waste water. Melissa Naidoo, AEL Environmental Manager, explained: “The root system absorbs the nitrates and creates microorganisms that utilise the nitrates to promote a healthy ecosystem.”

Results to date have been very pleasing. Nitrate levels have reduced by 75% - from 200ppm to less than 50ppm. The reed bed will be replaced every three years or when its efficiency declines.