With a view to developing a simple household method for removing iron
from water, a laboratory study was undertaken to assess the potential
of potassium permanganate, ceramic candle filter, or a combination of
the two in removing iron from iron-spiked tap water. Batch tests using
potassium permanganate with 5 min slow mixing and 2.5 h settling show
ed an iron removal in the range of 79-99% for the water samples tested
(pH 6.0-10.0; initial iron concentration 3.5-10.0 mg/L). The optimum
dose of potassium permanganate varied between 1.6 and 8.0 mg/L. Remova
l was generally higher at higher pH. Tests with a ceramic candle filte
r showed that, used alone, it could not remove iron efficiently; remov
al ranged between 7 and 20%. However, when water mixed with potassium
permanganate (for 5 min) was fed into the filter, a high iron removal
(91-99%) was observed. An Escherichia coli challenge lest showed impro
ved bacteria removal in presence of potassium permanganate. The result
s of the study indicated that a combination of potassium permanganate
and candle filter can be used effectively for the household removal of
iron in the rural areas of developing countries.