Capillary pressure method for measuring lipophilic hydrophilic ratio of filter media

Lipophilic Hydrophilic Ratio (LHR) was defined based on Washburn equation. The LHR values of five filter media were calculated from the wetting rates of cyclohexane (apolar) and water (polar) through compact filter media beds measured by capillary pressure method. The surface structures of filter media were characterized by X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR). It was confirmed by great regression coefficients and reproducibility of wetting rates that the values have a good reliability and the technique is applicable. The LHR values of nutshell, manganese sand, ceramic granule, quartz sand and ceramic sand are 66.87, 1.24, 1.22, 1.16 and 0.80, respectively, which shows that nutshell is much more lipophilic while manganese sand, ceramic granule and quartz sand are somehow more lipophilic than ceramic sand. This fact is consistent with the results of XPS and FTIR.