... of great amount of pollutant entrapment, up to 9-10 kg/m3, about 1.2 or 1.5 times that quartz ... sand filter of 7.8-9 kg/m3;4. Great mechanical strength, less abrasion loss, and ... ):Φ0.5-1,Φ1-2,Φ2-3,Φ5-6,Φ6-8,Φ8-10,Φ10-12,Φ13-16,Φ16-20,Φ20-30. Ceramic ...