January 24, 2007
Severn Trent Services has received a patent for its technology related to a method for removing silica from water treatment adsorption media. Severn Trent’s new method solves the problem of silica interference of arsenic and other contaminant treatment adsorption media. Silica, or silicon dioxide, exists naturally in many ground water sources. When the ground water passes through a bed of adsorption media, the silica present in the ground water is believed to encapsulate the media particles, and acts as a barrier to adsorption of other contaminants. The silica coating clogs the pores of the adsorption media and severely limits the ability of the media to remove contaminants from the water. The intermittent addition to the media bed of a scrub solution composed of NSF-approved products can significantly increase the adsorptive capacity of the bed. The arsenic removal media bed soaks in the scrub solution until silica is removed from the media particles, usually 20 minutes at the beginning of a routine backwash cycle. The scrub solution containing the silica is then removed and the media bed flushed during a normal backwash.