From Ground Water Currents, April 1995, Issue No. 11

Hydrocarbon Filtration Recovery System

By Laurel Staley, EPA Risk Reduction Engineering Laboratory

The InPlant Systems, Inc. SFC Oleofiltration System (SFC System) is a hydrocarbon recovery technology that utilizes an innovative amine-coated ceramic granule to separate suspended and mechanically emulsified hydrocarbons from aqueous solutions. These granules form an oleophilic filtration system (the Oleofilter) that separates some chemical emulsions and reduces concentrations of dissolved hydrocarbons. The Superfund Innovative Technology Evaluation (SITE) Program conducted a demonstration of the SFC 0.5 System at the Petroleum Products Corporation site near Fort Lauderdale, Florida during June 1994. The site is a former oil recycling facility where the groundwater has been contaminated with a variety of organic and inorganic constituents. Accidental releases during the operation of the facility deposited approximately 29,000 gallons of used oil on the ground water surface. The SFC System removed at least 90% of the total recoverable petroleum hydrocarbon (TRPH) fromthe emulsified oil/water feed stream.

The SFC System combines a conventional oil/water separator, a coalescing unit and the innovative Oleofilter into one unit, reportedly capable of treating virtually any oil/water mixture.Units are available in sizes capable of treating 2.2 to 50gallons per minute (gpm); other systems utilizing stand-alone components are capable of treating up to 600 gpm. All units operate at atmospheric pressure.

The oil/water mixture feeds into the top of the unit through a port, Port A, where free floating oil is removed by the oil/water separator. The emulsified oil then flows downward inside the outer shell of the unit and upward through a middle portion of the unit that contains plates that coalesce the oil. This oil, together with the oil initially captured by the oil/water separator, is discharged from the system through a second port, Port B, at the top of the unit. Final cleansing occurs as the remaining material flows upward through the center of the unitand then drains through the bed of oleophilic granules. The treated water than exits the system through Port C.

For the SITE demonstration, the feed oil was recovered from the site and thinned with lighter petroleum products. The feedstream to the SFC System was generated by emulsifying the feed oil and ground water using an air powered inline blender. The average TRPH concentrations for the feed streams ranged from 422 to 2,267 milligrams per Liter (mg/L). As stated, the SFC System removed at least 90% of the TRPH from the emulsified oil/water feed stream--with remaining TRPH concentrations in the treated water at 15 mg/L or less. The effectiveness of the oleophilic granules were evaluated by comparing the TRPH concentration in the water before passing through the granules. The granules were responsible for a 95% reduction in TRPH concentration for the runs with similar feed oil.

The oleophilic granules are produced by "grafting" a hydrophobicamine to a ceramic substrate through a series of substitution reactions. The amine's hydrophobic properties attract hydrocarbons present in an emulsion in water. The hydrocarbons remain attached to the amine by weak charges while the treated water exits the system. When the Oleofilter becomes saturated with hydrocarbons and suspended solids, it can regenerate itself by back flushing, which is built into the SFC System.

EPA is publishing a Technology Capsule and Innovative TechnologyEvaluation Report this Spring.

For more information about the technology and the report, call Laurel Staley at EPA's Risk Reduction Engineering Laboratory at513-569-7863.