Aeration and its application in groundwater purification

Aeration is an important process in water treatment on boreholes fitted with hand pumps and on small to large conventional water treatment systems. Aeration aids the removal of some pollutants such as iron and manganese, and similarly colour, turbidity, odour and taste. Studies have shown that water treatment levels predicted during aeration may not be achieved for iron and manganese if some other oxygen consuming substances are present in the raw water. Manganese removal is noted to be generally inefficient if aeration and filtration are the only processes applied during water purification. It has been observed also that, for such systems, pH of the effluent reduces as the water treatment process progresses. This results in dissolution of manganese and iron flocs formed and a short filter run.