Pyrophyllite clay for bacteriophage MS2 removal in the presence of fluoride

The aim of this study was to investigate the removal of the bacteriophage MS2 from aqueous solution using pyrophyllite. Batch experiments were conducted to examine MS2 sorption to pyrophyllite. The influence of fluoride, a groundwater contaminant, on the removal of MS2 was also observed. Column experiments were performed with pyrophyllite to examine MS2 removal in the absence and presence of fluoride. Batch results demonstrated that pyrophyllite was effective in MS2 removal. The percentage removal of MS2 increased from 5.26% to 99.99% (4.0 log removal) with increasing pyrophyllite concentrations from 0.2 to 20 g/L. At fluoride concentrations of 5 and 10 mg/L, the log removals of MS2 by pyrophyllite were 3.05 and 2.54, respectively, which were lower than that with no fluoride present. The results suggested that the removal of MS2 by pyrophyllite was influenced by fluoride ions because fluoride ions could compete with MS2 for sorption sites on the pyrophyllite surfaces. Column results showed that pyrophyllite was effective in MS2 removal under flow-through conditions, with a removal capacity of 8.17 × 10⁶pfu/g with no fluoride present and 4.70 × 10⁶pfu/g with 5 mg/L fluoride present.