Removal of iron from potable water using a trickling filter

A trickling filter for iron removal from potable water has been constructed and tested. Iron removal was found to be caused by both biological and physico-chemical iron oxidation. The extent of each oxidation type was assessed. In addition, iron concentration profiles were taken along the filter depth, for both biological and physico-chemical iron oxidation, under the same operating conditions. Significant quantities of iron precipitated, mandating a periodic filter backwash. The possible duration of the filter operating cycles was studied as a function of the inlet iron concentration and the volumetric flow-rate. The limits of feed iron concentration and hydraulic loadings on the filter were determined and appropriate operating diagrams were constructed.