Visualization of the Microbial Community and Elemental Mapping of Anadara granosa Media Used in a Slow Sand Filter Using a SEM-EDS

The removal of contaminants in slow sand filters occurs mainly in the biofilm above the filter media called schmutzdecke - a thin biological layer consisting of various microbial communities of algae, bacteria, diatoms and zooplankton. The layer formed ripens along with continuous straining and adsorption mechanism of impurities in raw water. Anadara granosa shell has been broadly used as an adsorbent to trap organic matter, turbid particles and heavy metal ion in raw wastewater. This research is aimed to visualise the microbial community grown on schmutzdecke in 2-weeks ripening period and maps the elemental characterisation of a grinded Anadara granosa shell media after the ripening period using a Scanning Electron Microscope with Energy Dispersive X-ray Spectroscopy (SEM-EDS). The result shows that mostly algae and diatoms have been recognised without species identification. Calcium (67%) and oxygen (21%) dominate the major chemical element contained in grinded Anadara granosa shell media, indicating that calcium carbonate and calcite can replace conventional sand as a more-efficient slow sand filter media, with longer maturing period. Such result can lead to further research about the increase of clamshell usage as a slow sand filter media to treat any types of wastewater, especially in rural areas in developing countries.