For the removal of free chlorine, dissolved organic matter, odor, taste, color and synthetic organic contaminants.

WIA’s granular activated carbon (GAC) filtration systems remove contaminants from water through adsorption, during which negatively charged contaminant ions are attracted to the positively charged activated carbon. Organic compounds are removed by absorption, and residual disinfectants such as chlorine and chloramines are removed by catalytic reduction.

Granular activated carbon is usually placed in a pressure vessel or gravity filtration tank through which the raw water passes. Carbon filters mechanically trap dirt, sediment, algae, bacteria, microscopic worms, cryptosporidia and asbestos. When the surface of the carbon granules is clogged with contaminants due to adsorption, the pressure difference increases and the filtration bed is washed in reverse.