Oxidation and precipitation is the most common
method to remove Mn(II). Such method is
based on the Mn(II) oxidation to its insoluble
manganic dioxide, followed by clarification and/
or filtration [8–10]. Oxidation can be achieved
by aeration or by using strong oxidizing agents
such as potassium permanganate, hypochlorite,
chlorine dioxide or ozone. Enhanced filtration can
be carried out by conditioning the filter media with
permanganate to form a manganese oxide coating
on the surface of the media or by using greensand
[11,12]. Manganic dioxide is also found to
adsorb the manganese ion which can be progressively
oxidized with time [13].
Mn removal by aeration-filtration can required
a long detention time [13] and a declined removal
percentage could be obtained compared with the
pH increment alone [14], therefore a strong oxidant
is required.