Carbon filters remove sediment but they also remove chlorine, volatile organic compounds (VOCs), odors and unpleasant tastes from water.  Carbon filters contain activated carbon, which is made through a special manufacturing process that creates more bonding sites. As water passes through a carbon filter, impurities like VOCs and heavy metals become chemically bonded to the carbon.  As the water works its way through the filter, a lot of unwanted impurities will become stuck to the carbon bonding sites and the water will leave the filter much more pure than it came in.