The present study examined the potential of some roughing filter media, prepared from locally available materials in removing organic matter and turbidity from surface water. Also, the study included testing the efficiency of roughing filter followed by slow sand filter in minimizing the suspended load on the subsequent water treatment steps. Based on microorganisms removal and turbidity data, filter media consisted of three layers of gravel ranked top among six of the media tested, showing 84-100 removal for chlorophyll 'a', green algae, blue-green algae, diatoms, total algal count, bacterial count (at 22 and 37 degrees C), total coliforms, faecal coliform, faecal streptococci, yeast and Candida albicans. Using slow sand filter after roughing filter improved the percentage removal of turbidity, where it reached up to 83 after roughing filter while it reached 92 after slow sand filter. From the view point of aesthetic quality of the filtered water, the results of the analyzed physico-chemical parameters showed no change before and after the use of the roughing and slow sand filters. References: 10
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