Activated carbon The adsorption process is a good process for removing organics in water at present. Due to the rich source of raw materials and large surface area, it has good removal rate for color, smell, taste and other organics. Activated carbon is widely used in water treatment. Among them, powdered activated carbon is particularly effective in removing low molecular weight DOC produced by algal cell secretions in water, and can effectively remove microcystins in water. Adding an activated carbon filter behind the classic slow sand filter can remove organic substances that cause water odor. The rapid biofilter with granular activated carbon as the filter material is usually used as the second stage filtration to remove BOM in water through the activity of bacteria growing on the surface of granular activated carbon. This process is also called secondary biological activated carbon filtration. The application of biological filter to remove BOM in water has the following advantages:

(1) It reduces the nutrients needed for bacteria to grow in the water supply system, which can effectively control the propagation of bacteria;

(2) The amount of organics reacting with disinfectants is reduced, thereby reducing the amount of disinfectants required for drinking water treatment and stabilizing the content of residual disinfectants in factory water;

(3) By removing the organic precursors of some disinfection by-products, the content of disinfection by-products in the water plant is reduced;

(4) Transforming organic matter into inorganic end products;

(5) The aged and fallen biofilm residue is easier to be treated than the chemically precipitated sludge;

(6) The cost of biological treatment method is lower than that of activated carbon adsorption method.