Comparative Performance Of A Charcoal Dual Media Filter And A Conventional Rapid Sand Filter

  • B. O. Sanyaolu
Keywords: Charcoal, Dual media filtration, rapid sand filtration


Filtration tests were conducted to assess the performance of a dual media filter (DMF) using charcoal in comparison to a conventional rapid sand filter (RSF) for the same kaolin solution in influent water. Assessment of media characteristics was based on appearance, size, relative density, acid solubility and physical stability. The dual media filter exhibited a turbidity removal capacity of 1.4 times that of the conventional rapid sand filter. Gradients obtained from plots of headloss against time for the RSF and DMF were 0.2 and 0.5 respectively indicating a higher rate of head loss development in the RSF than the DMF. About 86% of the accumulated material in both RSF and DMF was washed away during the first four minutes of backwashing with combined air and water scour. The DMF had a higher bed expansion rate of 40% more than the RSF. This could be attributed to the lower density of charcoal compared with sand.   



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