Filtralite – Biological Water Filtration Media



Water Treatment Filtration Media


Granular filtration is a water treatment process that uses granular material such as Filtralite® expanded clay, sand, anthracite, and other types of granular filtration media to remove impurities. Granular filters are most effective in removing suspended particles like sand, clay, iron and aluminum flocs along with biological matter such as bacteria, algae, protozoa and other pathogenic micro-organisms.

The effectiveness of granular filtration depends on the type of filtration media used. There is a wide array of granular filtration media types available on the market today that include Filtralite® expanded clay, quartz sand, silica sand, anthracite coal, garnet, magnetite, and others. Silica sand and anthracite are the most commonly used types. The size, shape and inner porosity of the filter media affect the efficiency of solids removal and biological filtration activity occurring within the media bed.

With its exceptionally porous and high surface area ceramic structure, Filtralite® offers increased filtration velocities along with improved particle removal and retention capabilities. The sharp, angular Filtralite® media form large voids and remove more fine material than rounded media of equivalent size. These highly porous, sharp edged filtration particles – illustrated below – have an extremely high surface area to volume ratio, low acid solubility, high resistance to mechanical abrasion, and a service life of over 20 years. Compared to sand and anthracite, media with high inner porosity like Filtralite® have greater capacity to retain suspended solids, substantially reducing required backwash frequency and supporting increased filtration velocities.


Close up view of the porous material inside clay media.


To guarantee the most effective filtration for our clients, Filtralite® is a key ingredient in our leading edge biological treatment system, SIBROM (Sapphire Biological Reverse Osmosis Membrane). It can also be used in other biological water treatment systems, wastewater treatment systems, or to replace sand and anthracite in existing mixed media filter beds.


Biological Filtration

Owing to its light weight porous structure and high surface area to volume ratio, Filtralite® is an ideal support medium for biofilm forming bacteria in fixed bed bio-filters. Granular filtration alone does not remove dissolved solids, but when combined with a membrane filtration process in Sapphire Water’s SIBROM system, can remove both suspended and dissolve solids from surface, ground, and wastewater sources.

Wastewater Treatment

Sapphire Water uses Filtralite® is in conventional secondary and tertiary sewage treatment processes. Its high surface area to volume ratio and jagged surface structure provides an ideal support media for the attachment and growth of the various consortia of bacteria. These bacteria are responsible for the essential biological treatment processes employed in the majority of municipal sewage treatment facilities.