Water Treatment » Iron Manganese Removal

Iron Manganese Removal

Iron Manganese Removal - PDF >

One of the most common problems associated with water supplies from boreholes is the presence of dissolved iron and manganese.

When used for domestic consumption Iron and Manganese makes its presence known by staining on sanitary ware or discolouration of laundry. It can also impart a taste and odour to drinking water.

Iron is found in water when it is dissolved from the soil (often by acidic water). It will lead to brown or rusty staining whilst manganese can cause brown coloured marks in Laundry and can leave black deposits on fixtures such as taps and showerheads.

Water can often look perfectly clear when it leaves the borehole, but leave it to stand for 24 hours and red rust deposits can be found to have settled out. This is caused by
soluble iron being present in the water and deposits out by the reaction of oxygen on the dissolved iron which then becomes oxidised and deposits out as iron oxide. If the water immediately appears to be red, then insoluble iron is present.

Unfortunately, iron and manganese can be quite difficult to remove from water as they may be present in several forms each requiring a different method of treatment.

In order that the correct treatment method can be proposed, the best starting point is a recent water analysis. This will tell us several things, most importantly the level of contamination and type, the pH (acidity or alkalinity) of the water supply, and other factors that may require treatment if the water is to be used as drinking water (ie presence of bacteria).

Current legislation states that potable water should contain no more than 200 ppm (parts per million) of Iron and 50 ppm Manganese.

Often one of the first stages of Iron and Manganese removal is to raise the pH, as many of the resin medias used in iron and Manganese removal, work more effectively as the pH is revised toward neutral or even alkaline levels.