Comperative Performances of Single and Dual Media Filters of Sand and Burnt Oil Palm Shell

Filtration is a common unit operation in water treatment plant. The most widely used filter media is in granular form such as sand, anthracite, coal, magnetite, garnet and coconut shells. The effectiveness of granular filter media in treating surface water has been already well established. However, there is a need to find an alternative source of granular filter media, since the costs of operation and water production have increased from time to time. Currently, a study has been conducted on palm shell as potential granular filter media. Palm shell is one of the industrial waste that is abundantly available. In this study, sand and burnt oil palm shell (BOPS) were used as single and dual media filters at different effective sizes, Es (i.e. Es of 0.4 and 0.6 for sand, Es of 1.0 and 2.0 for BOPS) and flow rates (i.e. 10 and 15 m3/m2.hr). The performances of filter are influenced by filter bed depth, influent water quality, flow rate and effective size. Result suggests that all the filters are capable of producing water with acceptable turbidity unit ( 1 NTU). The total running time and filtrate water quality produced by BOPS/sand dual media filter is much better than BOPS and sand single media filters (i.e. running time of BOPS/sand is four to nine times greater than single media filter)