Potable water

Granular media downflow filters remain the “work horses” of water treatment.  For facilities 2 MGD and above, Poseidon Filtration Systems® in concrete tankage will structurally provide a century of service.  Sand and anthracite dual-media filters are common, with granular activated carbon and greensand also utilized to remove additional contaminants.

Biologically Active

Without pre-chlorination, a granular media (commonly activated carbon over sand) filter may be used to also support natural biological activity in order to remove biodegradable organic matter, ammonium, and perchlorate, and other substances from drinking water.  The underdrain nozzle screens of the Poseidon Filtration Systems® directly retain the filter media, making a gravel packing layer unnecessary, while their slot size is maximized to negate biological fouling.

Wastewater Treatment System

Following wastewater secondary clarification, granular media filters provide excellent supplemental removal of suspended solids, including particulate BOD, chemically-precipitated phosphorous, and other solid-form contaminants above 5-10 microns. For facilities 15 MGD and above, Poseidon Filtration Systems® provide reduced maintenance and enhanced mechanical reliability over other wastewater filtration technology, to include disk filters, upflow filters, and compressed media filters.


In post-filtration applications, granular activated carbon (GAC) or ion exchange (IX) resin is used to adsorb or chemically remove natural organic compounds, synthetic chemicals, unpleasant taste, and odor in order to highly purify water.  Treatment of perfluorinated compounds (PFCs), pharmaceuticals, and personal care products may require multiple treatment technologies, to include adsorption or IX, for acceptable removal efficiencies.  Poseidon Filtration Systems® are the economic choice for flow rates that cannot be properly addressed by GAC or IX pressure vessels.

Wastewater Treatment

Excess nitrogen in wastewater effluent may lead to eutrophication (algae growth) in receiving waters.  The Orthos Denitrifying Deep Bed Filter (DDBF™), a wastewater treatment process of the Poseidon Filtration System®, provides fixed‑film biological denitrification in a downflow filter configuration.  With proper chemical treatment, the DDBF™ is capable of meeting stringent effluent limits of total nitrogen as low as 3 mg/l, total suspended solids to 2 mg/L, and total phosphorus to 0.3 mg/L or less.

Reverse Osmosis

Membrane systems (e.g., ultra- and nano-filtration, reverse osmosis) have highest flux rates when pretreatment provides consistent feedwater with solids of low particle size (e.g., less than 5 micron).  Because granular media filters may reliably produce membrane feedwater with fewer, relatively-large particles per volume than other filtration technology, choose Poseidon Filtration Systems® to optimize treatment efficiency and reduce O&M expense.