Removal of Emulsified Oil Using Xextex

Introduction -  Oil-water emulsions, where the oil is so dispersed that the water becomes translucent is one of the most difficult industrial effluents to treat.  Because the oil is partially dissolved, many filtration products and sorbents are completely ineffective.  Tests of effluent from Cascade Hardwood Corporation, a local company that operates a vehicle washing facility, had indicated that X-TEX filter media works well for some emulsified oils.  A series of experiments were performed to further determine the ability of X-TEX to remove the emulsified oil component in an effluent stream.

Method-  An emulsified stock solution was made by adding 5.0 ml of used motor oil and 5.0 ml of diesel fuel to 200 ml of water. Ten mls of citrus-based degreaser was added as an emulsifying agent and mixed vigorously.  From the emulsified-oil stock solution, three different concentrations of emulsified oil-water mix were tested:

  • Low – 1.0 ml of stock solution into 1.0 liter of water
  • Medium - 10 ml of stock solution into 1.0 liter of water
  • High - 100 ml of stock solution into 1.0 liter of water

A 15cm by 6cm diameter cylinder filter housing was constructed for this test and filled with 20 grams of bulk X-TEX.  The filter media was wetted prior to the start of the test. The test solution was run through the filter at a rate of 500 ml per minute and the first filtrate was discarded.  An additional portion of the test solution was filtered and a sample was taken. Unfiltered and filtered samples were analyzed using EPA Method 418.

EPA Method 418 is an oil and grease analysis that measures hydrocarbons as well as fatty soaps.  The samples were extracted and a silica gel cleanup was performed. This cleanup step removes fatty acids and soaps from the sample, leaving the diesel and motor oil components to be measured.

Standard solutions were made using motor oil.

Results -  The results from these tests confirmed that X-TEX can dramatically reduce the emulsified oil portion in an effluent stream. Table 1 summarizes the results of these tests.

Table 1 - Summary of Results

Result (ppm)
Percent Oil Removal

Low Level (before X-TEX)



Low Level (after X-TEX)






Med Level (before X-TEX)



Med Level (after X-TEX)






High Level (before X-TEX)



High Level (after X-TEX)



At the medium and high levels X-TEX removed greater than 90 percent of the oil.  Competing products that remove floating oil have generally proven ineffective with partially dissolved or emulsified oil.

The potential use of X-TEX sorbent material where emulsified oils exist include: 

  • Vehicle wash facilities
  • Bilge water
  • Petrochemical and Refineries wastewater
  • Ocean oil drilling platform process water
  • Tank ballast water, de-oiling
  • Retrofitting existing oil water separators on existing pollution prevention equipment (final polishing)


The Xextex Corporation, USA

Jerry M. Brownstein
President & CEO
1420 NW Gilman Blvd. #2227
Issaquah, WA 98027

Phone: (425) 392.3848
Fax: (425) 392.0222


90 SEC

X-TEX Outperforms Polypropylene



*X-TEX does not produce
potable water.

10.5 MIN