The characteristics of limestone and anthracite coal as filter media in treating pollutants from groundwater

Abstract

The performance of limestone and anthracite coal were evaluated for the removal of pollutants from groundwater. The physical and chemical properties of two filter materials were characterised through X-Ray diffraction (XRD), X-Ray fluorescence (XRF), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). XRD analysis showed that the main peaks of calcite (CaCO3) are the predominant phase of limestone, whereas quartz and graphite are the crystalline phase of anthracite coal. The presence of calcium oxide (CaO) as the major composition indicated that limestone demonstrates a good ability for cation exchange. FTIR spectrum analysis showed that the functional groups present on the limestone surface are mostly hydrophilic groups, and anthracite exhibits hydrophobic characteristic. Limestone has the potential to adsorb heavy metal pollutants, whereas anthracite has the capability to adsorb organic pollutants. Therefore, the two filter materials can be used as alternatives to remove pollutants in treating groundwater.