Calgon Carbon Answers Your PFAS Remediation Related Questions

You may have heard that “PFAS are being classified as hazardous” and be asking yourself:

“What does this mean and how does it impact the use of granular activated carbon (GAC)?”

The recent PFAS regulations are unprecedented, impacting industries, communities, & ultimately, our daily lives.

US EPA April 2024: released a Final Rule Designating PFOA and PFOS as CERCLA Hazardous Substances.

    • Designated two PFAS compounds, PFOA and PFOS, as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as the Superfund Statute.
    • Per the EPA: “This step improves transparency and accountability to clean up PFAS contamination in communities. In addition to the final rule, EPA issued a separate CERCLA enforcement discretion policy that makes clear that EPA will focus enforcement on parties who significantly contributed to the release of PFAS chemicals into the environment.”

US House of Representatives April 2024 introduced H.R. 7944, “Water Systems PFAS Liability Protection Act.”

    • Proposes exemption to public water systems and public or private treatment works from liability under CERCLA (above), among others.
    • The American Water Works Association (AWWA) supported this exemption stating: “The American Water Works Association (AWWA), as a member of the Water Coalition Against PFAS, supports the introduction of bipartisan legislation that would provide liability protections for water systems under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) for per-and polyfluoroalkyl substances (PFAS), and help ensure that polluters, not the public, pay for PFAS cleanup.”

For frequently asked questions about GAC, Reactivation, and CERCLA, please see below or click here.

GAC, Reactivation, and CERCLA

Can my utility use Calgon Carbon to take my CERCLA hazardous substance away and dispose of it through reactivation?

YES, Calgon Carbon is equipped to transport and provide reactivation services for CERCLA hazardous substances impacted customers using FILTRASORB® products. PFOA and PFOS being designated as CERCLA hazardous substances is no different.

I want to reactivate and reuse my GAC containing a CERCLA hazardous substance, such as PFOA or PFOS, can Calgon Carbon still help me?

YES, Calgon Carbon can provide Custom Municipal Reactivation (CMR) services, or react and return, for customers with CERCLA hazardous substances. Calgon Carbon has worked with CERCLA sites, and reactivation can meet market needs and various regulatory requirements as they arise in the future. For example, drinking water utilities may also be asking how the recent DRAFT proposal to list 9 PFAS as “Hazardous Constituents” by the Resource Conservation and Recovery Act (RCRA) will impact them. Calgon Carbon can handle and process RCRA hazardous constituents.

If we use the CMR process and reactivate and reuse our GAC, can we save money?

YES, CMR is a great way to save money and sustainably operate a GAC system. Typically, reactivation can occur at least five times.

Are there other factors to consider besides cost?

YES, from a non-cost perspective, CMR results in a lower CO2 footprint (up to 80%) compared to virgin exchanges, prevents using additional natural resources, and ensures customer-dedicated, domestically produced GAC supply.

Can I expect reactivation to remove PFAS from the GAC, ultimately yielding the same level of removal and performance when using a CMR product, or reactivated GAC, to treat PFAS?

YES, the reactivation process removes PFAS from the surface of GAC with minimal change to the carbon. This means that the CMR product typically performs the same as virgin GAC for PFAS removal and is a great cost saving measure. As with any site-specific question, pilot testing can help demonstrate this phenomenon. 

Our PFAS Removal Process

Who is Calgon Carbon?

We are the unrivaled authority in the treatment of PFAS, combining proven and effective products, processes, and testing programs with a team of professionals focused on safeguarding local water supplies.

We are the largest, most capable and most diverse activated carbon manufacturer and solutions provider for air and water treatment.

We set the standard for the industry with hundreds of patents and a team of scientists and engineers dedicated to developing new processes, standards, and methods.

What does Calgon Carbon specialize in?

We specialize in on-site support, providing a host of top-notch field services to install and remove carbon in the most efficient and safe manner – maximizing the customer’s economic benefits and minimizing disruptions to the operations.

How did Calgon Carbon get started?

We started in the 1940s, providing activated carbon solutions for the U.S. military. Over time, we evolved. We became pioneers in drinking water treatment and have a long legacy of solving customer problems for a variety of applications. With more than 75 years of experience, we are trusted, and we are proven.

What are the treatment solutions that Calgon Carbon offers?

For its industrial customers, we treat not just water but also the environment. The company offers a wide range of treatment solutions depending on the site challenge and discharge permit criteria. We offer PFAS treatment solutions for wastewater, air, process water, landfill leachate, and groundwater remediation.

How do I go about implementing the PFAS treatment process?

Our technical team can assist with testing and simulation to determine the optimal PFAS treatment configuration for municipal and industrial settings.  This collaboration offers the most cost-effective investment process, which helps clients avoid mistakes that could increase the cost and timeline for effective treatment.

How do I know Calgon Carbon is reliable?

Our technical experts know that testing helps them determine the best treatment option. As a result, we perform more tests than any other manufacturer and have more capabilities than our competitors. Thorough testing determines the best course of treatment, including ion exchange or GAC.

About Calgon Carbon

How does granular activated carbon (GAC) remove PFAS from water sources?

GAC works through a process known as adsorption. In this process, the activated carbon can be thought of as a magnet that is removing contaminants from water as it passes through. Once that activated carbon is no longer removing contaminants, it is replaced with fresh or reactivated carbon so that you have continuous removal.

What is reactivated carbon?

Reactivated carbon is GAC that has been thermally treated once it is at the end of its useful service life, when it is known as spent carbon. It goes through a process that vaporizes and destroys adsorbed contaminants at extremely high temperatures and restores the GAC to a near-virgin state so it can be reused.

What exactly does the reactivation process look like?

In reactivation, the spent activated carbon travels through a multi-hearth furnace or rotary kiln, which restores the activated carbon to a virgin-like state. Using thermal treatment at high temperatures of up to 1750 degrees Fahrenheit, this step vaporizes and destroys contaminants in the furnace or kiln itself. The goal of this first step of reactivation is to restore the structure of the activated carbon, and the operating conditions (temperature and steam addition) are tuned for that purpose. 

What happens to the contaminants after they are removed from the GAC?

Any contaminants that survive the high-temperature furnace travel to the abatement system for further destruction. 

What does the abatement system look like?

The pollution abatement system for reactivation consists of a thermal oxidizer / afterburner, a scrubber, and a baghouse. Our abatement system is designed to destroy organics to meet regulatory limits, typically to at least 99.99% efficiency. The system also neutralizes acid gases formed during the process and captures particulates.

Are there other processes that can be used to remove contaminants from GAC?

There is carbon regeneration, which uses a lower-temperature treatment – typically below 400 degrees Fahrenheit with steam, nitrogen, or other hot gas – for short periods of time to remove only a portion of the adsorbed contaminants, producing a partially spent carbon that contains some, and potentially all, of the original contaminants.

We do not use the carbon regeneration process, but instead a reactivation process that relies on thermal treatment at high temperatures greater than 1700 degrees Fahrenheit for hours at a time.

What is FILTRASORB?

Our FILTRASORB® is a re-agglomerated GAC produced from bituminous coal that has demonstrated superior PFAS-removal capabilities compared to other carbons and acts as a high-performing carbon for a variety of other compounds as well.

We offer a full range of GAC adsorption equipment and activated carbon products to treat PFAS. This simple and effective solution requires little operator involvement. Our equipment is uniquely designed to ensure no water escapes without being in contact with our activated carbon product. In an application with no room for error, choosing the right equipment and the right carbon is critical.

AquaKnight™ FAQ

Drinking Water Equipment that will safeguard your water to the highest standards. 

What is the difference between Calgon Carbon’s AquaKnight™ equipment and your previous equipment with “model” in the name?

Calgon Carbon has been implementing high-performing adsorption equipment for over 35 years and has developed expertise in design, manufacture, and utilization of activated carbon solutions. These solutions offer customers the lowest total cost of ownership along with superior performance, ease of carbon changeouts, and the ability to treat to very low levels. This last point is extremely relevant for applications such as PFAS treatment that require removal to below the detection limit of 2 parts per trillion. As demands in the water treatment industry become higher and regulations become more stringent, having a highly engineered proven solution is critical. Our AquaKnight systems combine our experience, proven solutions, and best-in-class design, and offers it to our customers as a standard, off-the-shelf solution. 

If you’ve purchased our standard Model “#” systems in the past for your drinking water needs, you’ve already benefitted from this expertise. The AquaKnight name is being launched to ensure that when you buy a Calgon Carbon treatment system, you know that it is expertly designed and proven to protect and safeguard your drinking water from contaminants such as PFAS and others. In addition to an optimally designed system, coupling the AquaKnight equipment with Calgon Carbon’s FILTRASORB® granular activated carbon (GAC) provides the added benefit of simultaneously removing many different contaminants such as disinfection by-products (DBPs), 1,2,3-TCP, TOCs, VOCs, algal toxins, and Taste & Odor (T&O) Causing Compounds.   

What AquaKnight equipment options are available from Calgon Carbon for treating drinking water?

We offer two primary options to meet our customers’ needs and provide the flexibility needed.  The two types of AquaKnight systems are 1) Gold Certified (GC) and 2) Custom Certified (CC).  The AquaKnight Gold Certified, or GC, designation applies to a two-vessel system that is certified in its entirety by the National Sanitation Foundation to Standard 61 (NSF 61) for Drinking Water System Components.  The AquaKnight Custom Certified, or CC, designation applies to either systems or single vessels, where each individual component that is in contact with the water is NSF 61 certified, rather than the entire packaged system.

What are the benefits of the Gold Certified (GC) systems over custom built vessels?

The AquaKnight GC system is fully NSF 61 certified for the entire system. It provides a more cost-effective and timely approach than customizing and certifying each component.

What do the numbers in the name mean?

The numbers represent the size and capacity of each vessel. For example, one of Calgon Carbon’s most frequently requested vessels, the Model 10 system is comprised of two 10-foot diameter vessels, hence the Model 10 naming convention.  Moving forward this system will be referred to as AquaKnight GC 10 (or CC 10) in drinking water applications. 

The Research

Why did Calgon Carbon conduct a study on the reactivation processes?

To address questions that have persisted about the effectiveness of the reactivation process for the destruction of PFAS, we did a thorough stack testing program at a full-scale, company-owned GAC reactivation facility during the reactivation of a load of GAC known to contain a high level of adsorbed PFAS.

What did Calgon Carbon find in its study?

The data from our stack testing program demonstrate that reactivation of PFAS-laden GAC in a facility operating a multi-hearth furnace with appropriate abatement system results in high levels of destruction of PFAS compounds – including removal of PFAS compounds from GAC and greater than 99.99% destruction of PFAS compounds through the furnace and abatement system.

What was the most significant finding of the study?

The most significant finding is the confirmation that not only is PFAS removed from the activated carbon to below detectable levels, but PFAS destruction occurs in the reactivation furnace and robust abatement systems.

Why are the findings of the study important?

Our research is critical in this space. Everyone wants to know what happens to PFAS once they are removed from water. This research demonstrates that, through our proprietary reactivation process, we can remove PFAS from the activated carbon and destroy them to greater than 99.99%. The research is critical in answering the question, “What happens to PFAS once they are removed from the water?”

Was anyone else involved in this study?

We contracted with a third-party vendor specializing in manufacturing emissions testing to determine the emission rates of PFAS and hydrogen fluoride per established methodology. Additional outside vendors tested air samples for 36 PFAS compounds and analyzed well water and treated motive water samples for PFAS and analyzed samples of spent carbon, reactivated carbon, abatement dust, and bicarbonate raw materials for extraction and targeted PFAS.

* United States Environmental Protection Agency, LAST UPDATED ON MAY 8, 2024, https://www.epa.gov/superfund/designation-perfluorooctanoic-acid-pfoa-and-perfluorooctanesulfonic-acid-pfos-cercla, 2024, Accessed June 1, 2024

For more information and/or to have a Technical Representative reach out, please contact us at dws@calgoncarbon.com or 1-800-4CARBON; www.Calgoncarbon.com