Clark Technology Removes Per- and Polyfluoroalkyl substances (PFAS) From Source Waste Streams

By Dr. Kazem Oskoui | koskoui@clark-technology.com

Minneapolis, MN – July 2019: Per- and Polyfluoroalkyl substances (PFAS) are a group of durable and stable chemicals, which have been used for several decades in the manufacturing industry, for example, non-stick cookware, fire retardant materials, and stain-resistant carpets.  These same PFAS’, over time have found their way into the Nation’s drinking water supply via industrial discharge, compost piles, and especially landfill leachate. Landfill leachate is one of the most important and difficult-to-treat sources of PFAS’, which contribute annually to elevated levels of these contaminants in surface and groundwater.  Removing these substances from the acquis environment is a national and global challenge to the industry and regulatory bodies.

In search of a means to prevent this from happening and to safeguard the Nation’s ground and surface waters from being contaminated by these contaminants, Clark Technology, LLC (Clark) has innovated the LeachBuster® Treatment System which removes all PFAS contaminants (over 24 species) from waste streams, such as landfill leachate, thus preventing them from getting into drinking water supply sources.

Clark has designed and installed several LeachBuster® systems in the U.S. and around the world. One, in particular, is located in a landfill in Western Minnesota which has been running for nearly four years and has been removing these compounds from leachate utilizing a 20,000 gallons per day wastewater treatment plant.

Clark has numerous years’ worth of laboratory test data, some of which can be provided upon request. The followings are a sample set of data for a group of PFASs. Out of 24 species tested, approximately 15 species were present in one sample and 10 species were detected in the second sample all of which were removed by the system. Depending on the temporal and geographical locations, different species were detected in the raw leachate streams.

Another set of samples are also presented here from another landfill site to indicate the ability of LeachBuster® to remove PFAS from different leachate streams. These samples were collected following a rain event thus fewer species (10 out of 24 tested) were detected in the raw leachate.

*Acronyms are given in the previous table.

As it can be seen in both examples and at many other locations, regardless of the initial values of PFAS in raw leachate, the levels in the treated leachate were all below two (2) Parts per Trillion (PPT) or nano-grams per liter (ng/l), which is much less than the most stringent maximum contaminant level (MCL) and/or health risk limits (HRLs) set by any regulators in the U.S.

*PFNA: Perfluorononanoic acid  PFDA: Perfluorodecanoic acid: PFDoA: Perfluorododecanoic acid, PFBS: Perfluorobutanesulfonic acid, PFHpS: Perfluoroheptanesulfonic Acid, PFOS: Perfluorooctanesulfonic acid, FOSA: Perfluorooctanesulfonamide, PFHpA: Perfluoroheptanoic acid, PFOA: Perfluorooctanoic acid, PFHxS: Perfluorohexanesulfonic acid, PFBA: Perfluorobutanoic acid, PFPeA: Perfluoropentanoic acid, PFHxA: Perfluorohexanoic acid.