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[[Image:iron filter icon.png|right]]

[[Image:iron filter.jpg|thumb|right|250px|Building an iron filter. <br>Photo: PCWS]]

The iron removal filter (IRF) is a cylinder built using ferrocement construction techniques. Inside, from top to bottom order, is a plastic basin full of charcoal, a layer of gravel, and an empty space for sedimentation. The water to be treated (in this model the water is assumed to be from a hand pump spout) first passes through the charcoal, aerating it, flows to the empty space at the bottom via a pipe where sedimentation of the precipitated iron takes place, then wells up through the gravel for filtration purposes. The finished water accumulates above the gravel filter, and this elevation enables users to draw it.

==Construction, operations, and maintenance==

To use it for the first time, the filter is filled with water and allowed to overflow a little. The first discharge is turbid from the gravel, but this clears up after a day or so of use. After placing their buckets under the tap, the users just pump the hand pump, and by gravity the water enters and flows

through the filter, displacing the previous treated contents, which then overflows thru the taps into their buckets.

The gravel may also eventually clog up occasionally. Cleaning it is also by manual agitation while recycling water through the IRF. A bucket is placed under the open tap and the contents are led by pouring, dipper by dipper, back through the charcoal basin. In cases where deposits have built up in the

sedimentation space, a drain can be opened to clean this out. The worst that can happen is that the unit may eventually need overhauling. All parts are then taken out and cleaned, and clogs and leaks repaired.

==Acknowledgements==

* [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CKoBEBYwAQ&url=http%3A%2F%2Fwww.itnphil.org.ph%2Fdocs%2FIron%2520Removal%2520Filter.PDF&ei=PT_ZT8vKBOjD2QWp942rBw&usg=AFQjCNFNm2C1AYQdDm5RCYXIYTiSApR4yg&sig2=cZ3xdyp7j_aozRydD4jLGg IRON REMOVAL FILTER.] PHILIPPINE CENTER for WATER and SANITATION.