New System Tackles Arsenic Removal From Groundwater

USFilter's granular ferric hydroxide (GFH™) media system is a chemical-free alternative for removing high concentrations of arsenic from groundwater.

USFilter's granular ferric hydroxide (GFH™) media system is a chemical-free alternative for removing high concentrations of arsenic from groundwater. A cost-effective means to comply with the USEPA's 2006 Arsenic Rule, the media is ideal for wellhead systems and installations where no treatment currently exists. Plants with limited waste-handling facilities especially appreciate the GFH system, as it produces unusually low volumes of liquid waste on an infrequent basis.

The GFH system uses ferric-based, non-regenerative media to remove the arsenic, and other heavy metals from raw water supplies. The non-regenerative media alleviates on-site storage, handling of regeneration chemicals and regeneration waste.

Operated in a fixed bed adsorber, the media is installed typically in vertical pressure vessels that allow a single pumping stage for the treatment system. Like other adsorption processes, the water is simply passed through the media to remove the contaminants. The media does not require preconditioning or pre-oxidation procedures. Once the media has depleted its adsorption capacity, it is removed from the vessel and replaced. Exhausted media has passed TCLP tests and, in most instances, can be disposed of in a non-hazardous landfill.

Depending on water parameters, the GFH system is configured in a parallel or series arrangement, with an empty bed contact time of five minutes. The vessels are backwashed once every two to six weeks to prevent bed compaction and to remove trapped particulate.

Compared to other adsorption medias, GFH media has been demonstrated to treat more bed volumes between replacement, decreasing downtime. After conducting one-year bench scale and pilot studies, the city of Phoenix, AZ, concluded that GFH media treated more than five times the bed volumes of three other adsorption media options before being exhausted.

Phoenix is the first U.S. city to install a full-scale arsenic removal system using GFH media. The 1.5-mgd arsenic removal system contains 60,000 lbs of media.

European municipalities have used GFH media for years to meet the current World Health Organization and European Union standards of 10 mcg/L.

Change-out Service

As of March 2004, USFilter began offering communities the option of media change-out services, equipment leasing or capital purchase. Service to change out the media is available to all GFH media users. USFilter service technicians and equipment are used to safely remove the exhausted media and responsibly dispose of it in approved facilities. New media is installed during the same site visit.

"Larger systems are handled on-site, while the smaller systems are most economically handled at a regional facility where we bring the entire vessel in for change-out," said Chris Morss, vice president of remediation services.

Along with services, USFilter provides flexibility in ownership. Customers can opt to either purchase or lease the equipment and services.

"This gives our customers the flexibility to select what works best for them, both financially and operationally," said USFilter product manager, Roman Aguirre.

For more information about the GFH system, contact Aguirre at 719-622-5324 or Aguirrer@usfilter.com.

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