MODIFIED SLOW SAND FILTRATION USING CHANCHAGA RIVER BED SAND, SANDY SOIL AND QUARRY SAND DUST AS FILTER MEDIA

Slow sand filtration for the treatment of water was carried out using three different sand sources – Chanchaga River bed sand, sandy soil and quarry sand dust. The effect of varying bed thickness (8, 13 and 17 cm) and water flow rate through the sand beds for the different sand were tested and found to affect the purity of the filtrates. The characterization of the filtrates from the three sand sources and the various bed thicknesses showed that the results from all the sand bed filters analysed were within the acceptable limit of the standard (except total coliform) for drinking water used as basis in this research. Quarry sand gave the best result in terms of water purification while sandy soil had the least performance in terms effectiveness of filtration.