... specific surface area and porosity, When used in water treatment, they behave a activated surface property, a ... great amount of pollutant entrapment, less water head loss in the filter bed, lower consumption ... and efficient filter material to increase the water yield, upgrade the water quality, and save chemicals and energy. ... Φ10~12, Φ13~15, Φ16~20, Φ21~60. Waste Water Treatment Product