Application of granular activated carbon in advanced drinking water treatment

Activated carbon is the most commonly used adsorbent in water treatment. During the activation stage of manufacturing activated carbon, the voids generated between the carbon grain lattice form pores of various shapes and sizes, among which the macropore pore radius is 100~10000nm, the mesopore pore radius is 2~100nm, and the small pore pore radius is < 2nm, the total area of the pore walls of large, medium and small pores is the total surface area of activated carbon. The strong adsorption performance of activated carbon mainly occurs on the surface of these pores. In addition to the surface area, the adsorption capacity of activated carbon is also related to the shape and distribution of pores and the chemical properties of the surface. In general, activated carbon used for water treatment should have an appropriate proportion of pores to remove adsorbate with larger molecular weight (or molecular diameter) in the water. The surface of activated carbon has weak polarity, which can not only remove non-polar adsorbates in water, but also remove polar adsorbates and even some trace amounts of metal ions and their compounds.

The pollution of natural water sources can, in severe cases, cause eutrophication of water sources and the proliferation of algae, giving water sources color, odor and taste. Activated carbon adsorption is one of the most effective methods for removing color, odor and taste. In addition, activated carbon is also very effective in removing color from water caused by iron, manganese and plant decomposition products or due to organic pollution. In addition, using activated carbon to remove trace amounts of organic chlorine and the odor generated from water is also one of the most effective methods.