PFAS have recently entered the national spotlight as emerging contaminants with serious adverse impacts on human health, even at low concentrations in the parts per trillion range. Carbtrol offers a number of solutions for PFAS removal from water.
Perfluorinated and polyfluorinated alkyl substances are a group of over 4,000 manmade chemicals, collectively referred to as PFAS (or PFCs). PFAS are found in everyday items including fast-food wrappers, stain-resistant fabrics, nonstick cookware and firefighting foams, to name a few.
PFAS are water soluble and therefore can seep into surface soils over time at firefighting training facilities, airports, military bases, manufacturing sites, landfills, etc. From there, PFAS can leach into groundwater or surface water, and can subsequently contaminate drinking water.
PFAS, also known as “forever chemicals”, stay in the environment for a long time and do not break down easily. As a result, PFAS are widely detected in soil, water, air, and food. Some PFAS can accumulate in the food chain. Exposure can occur when someone uses certain products that contain PFAS, eats PFAS-contaminated food, or drinks PFAS-contaminated water. When ingested, some PFAS can build up in the body and, over time, these PFAS may increase to a level where health effects could occur.
Depending on your contamination level, water chemistry and application, we use a combination of granulated activated carbon (GAC) and/or ion exchange resin for PFAS removal to non-detectable levels. This technology follows the EPA guidelines for “Reducing PFAS in Drinking Water with Treatment Technologies.”
Granulated Activated Carbon (GAC) works well on longer-chain PFAS such as PFOA (Perfluorooctanoic Acid) and PFOS (Perfluorooctane Sulfonate). GAC is also used to remove dissolved oils, VOCs, and other organic compounds..
Also, it is important to remove particulates from the influent stream as well as after the carbon drums, in order to achieve the very low (ppt) discharge limits.
A typical 6 GPM PFOS/PFOA Removal System (shown) consists of a pre-filter, (2) L-1-CL Drum Filters, a post-filter, and a PK-10 piping kit. This equipment can be mounted on a poly skid for ease of installation and mobility.
A second technology, Ion Exchange, has also proven effective for PFAS treatment. The exchange media, while considerably more expensive than the activated carbon media, has been demonstrated to be cost effective specifically for low molecular weight PFAS compounds such as PFNA, PFHxA, PFHxS, PFHpA, PFBS, and PFBA.
Carbtrol has recently demonstrated a two stage treatment process which utilizes the strengths of both technologies. A two stage sorption process utilizing activated carbon in the first stage followed by ion exchange in a second stage treatment. This concept combines the strengths of both technologies. Flow diagram is shown below.
Activated carbon adsorption allows removal of the high molecular weight PFAS compounds at the most cost effective rate. Then by polishing with Ion exchange, addresses the low molecular weight compounds and minimizes the use of the more expensive ion exchange media.
Additionally, in most PFAS treatment applications, some level of non-target background organic contamination is present. In the two stage process the activated carbon can be used to address removal of the background material further maximizing the cost efficiency of the polishing treatment step.
Two Stage PFAS Treatment System
Contact a Carbtrol Sales Engineer today to review your application in detail!