The earliest volcanic birth of biological filter media in the United States, China was once linked to rely on imports to achieve the biological membrane technology, due to its high cost, the researchers developed a bio-ceramic instead. Today, our scientific research personnel in the country through the study of volcanic rock found a filter for processing of mineral resources, after processing, crushing, screening, grinding and a series of processing of the granular filter media, the main ingredients of silicon, aluminum, calcium, sodium, magnesium, titanium, manganese, iron, nickel, cobalt and molybdenum and other dozens of minerals and trace elements, and the apparent irregular particles, color is red, black and brown, porous light weight, particle size according to different requirements. 
 Appearance: 
 Irregular particles, color is dark brown. Porous light. 
 Uses: 
 Biodegradability of organic processing industrial wastewater, municipal sewage, domestic miscellaneous drainage, micro-polluted source water. 
 Features: 
 Volcanic rock biological filter is to achieve BAF sewage treatment process the key material, the product compared with traditional bio-ceramic, not only has the light texture, good chemical stability, strength suitable, easy to hang film surface roughness advantages Moreover, developed gap distribution is reasonable, very suitable for microbial inoculation, domestication, breeding growth. Wash-resistant, non-blocking, has good physical, chemical and hydraulic characteristics, can be adapted to different requirements of water purification. 
 Hydraulic Characteristics: 
 1, the idle rate: table uniform porosity of about 40% of the water resistance, while compared with the same filter, filter required less, the same filter to reach the expected goal. 
 2, than the appearance of plot: plot than the appearance of large, opening high and noble, beneficial microbes to fight the growth of biofilm and to link more microbial biomass, microbial metabolism in favor of the required course and metabolism of oxygen and nutrients birth place of the mass transfer process of the waste. 
 3, the filter shape and the water flow pattern: As the filter is not sharp volcanic grains, and the pore size is larger majority than the ceramic, Yi Shi in the use of water flow when the resistance is small, cutting energy consumption.