Final answer:
While a KF filter can reduce fluoride concentrations according to EPA and WHO guidelines, more rigorous treatment like reverse osmosis may be necessary to remove hydrofluorosilicic acid and achieve near-pure water.
Step-by-step explanation:
To come as close as possible to pure water and remove contaminants such as hydrofluorosilicic acid, a specialized filtration process may be necessary. A typical KF filter, or fluoride water filter, is generally designed to reduce the concentration of fluoride ions to levels set by the EPA and WHO, which are 4 ppm and 1 ppm, respectively.
While these filters can reduce fluoride levels, they may not completely remove hydrofluorosilicic acid if present in the water. To attain water with the fluoride levels as low to zero as possible, additional treatment methods such as reverse osmosis, activated alumina, or ion exchange might be required.
These methods can be effective at reducing the concentration of hydrofluorosilicic acid alongside other potential contaminants. It's also worth noting that the dissociation of hydrofluoric acid in water is negligible, especially when additional fluoride ions are present.
Furthermore, in dealing with the extraction of other potential additives or contaminants, a more robust water purification system would be recommended. Such systems could include a combination of treatments, like sediment filtration, activated carbon, UV treatment, and others depending on the specific contaminants likely present in municipal water supplies.