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Removing harmful per- and polyfluoroalkyl substances (PFAS) from industrial wastewater and surrounding environments is a clear goal with many murky considerations. Water treatment agencies are flooded with information on the dangers of PFAS and their obligation to manage their removal, and yet uncertainty persists.
Differing standards across regions, industries and environments can leave engineers with a dilemma – unsure of the precise actions to take or overwhelmed by alarmist messaging that calls for a complete system overhaul—when in fact the best solutions may already be in their hands. It’s time to take a dive into the challenges and solutions inherent to industrial water treatment, and reintroduce reactivated carbon as one of the most reliable treatment technology for general purification and PFAS removal.
Sources of PFAS compounds and how they enter industrial wastewater
First, let’s get the lay of the land—or in this case, water. A huge variety of industrial processes—from manufacturing to cleaning—involve the use and discharge of water, often containing other dissolved substances. These can include synthetic and organic chemicals, oils, pesticides, pharmaceuticals, and other industrial by-products, all of which are toxic and potentially hazardous to human, animal and aquatic life.
Within this broad category of pollutants and micropollutants, persistent bio accumulative and toxic substances (PBTs)—like persistent organic pollutants (POPs) and PFAS—pose a particular risk due to a high resistance to degradation and traditional physical and biological treatment methods.
Adding another layer of complexity, these factors are exacerbated by climate change and its effects on weather patterns. Abnormally heavy rainfall, flash flooding and more frequent storms mean a higher volume of PFAS-contaminated runoff may be discharged into nearby waterways, often with little opportunity for treatment. This understandably makes the effective removal of PFAS from industrial wastewater the subject of intense, and evolving, regulatory scrutiny to which affected companies have to pay close attention. How then can organisations ensure PFAS and other pollutants are safely removed from their industrial wastewater and stay on the right side of shifting regulations? The key is activated carbon technology.
Industrial wastewater treatment: How activated carbon supports PFAS removal
Activated carbon is composed of a random, imperfect arrangement of graphite platelets connected by carbon-carbon bonds which resemble a deck of playing cards. This unique composition creates activated carbon’s highly porous structure and an enormous internal surface area of more than 1,000 square meters per gram. The dual benefits of high porosity and vast surface area allow activated carbon to adsorb various organic and some inorganic compounds from air, gases and liquids, making it an ideal medium for industrial wastewater treatment.
Just 5 grams of activated carbon has a surface area equivalent to that of an average football field.
Selecting the right activated carbon treatment for your operations
Coconut shell, bituminous and sub-bituminous coal, lignite/peat and wood can all be used as starting materials for different forms of activated carbon, each with specific strengths and features. Wood-based carbon, for instance, has a lower density and fewer skeleton platelets, making it suitable for the removal of larger-molecule contaminants, but it cannot easily be recycled. Denser than wood with more graphite platelets, coconut-based carbon is ideal for gaseous applications and the removal of volatile organic compounds (VOCs) such as benzene, alcohols and various odorous compounds. For most industrial wastewater filtration projects however, coal-based activated carbon is the medium of choice thanks to its capacity for effective diffusion and high adsorption, as well as its ability to be effectively recycled via thermal reactivation
Selecting the most appropriate activated carbon source for any given application depends on several factors, including the types and range of contaminants required for removal, their concentrations, and the pH level of the waste stream involved.
Then there’s the issue of dilution. Compounds and substances with specialized characteristics, such as PFAS, tend to be used in specific or discrete processes, but they don’t always stay separate and easily contained. Contaminant-laden wastewater from one process may be mixed with cleaner run-off water from other plant areas, creating heavily diluted—yet nevertheless contaminated—bodies of water that must be treated.
When facing these and other thorny process considerations, industrial organisations can truly benefit from the support of an experienced wastewater treatment specialist. At Chemviron, we pour decades of expertise into delivering highly specific advice and recommendations tailored to the needs of each treatment situation or site. First, we carry out laboratory testing on a representative water sample to assess the likely carbon performance and determine the most appropriate technical solution based on the variety and concentration of contaminants present. We then can employ our highly efficient Accelerated Column Test (ACT), a technique that combines the speed of a traditional isotherm test, with the accuracy of a more in-depth, yet time-consuming, pilot column. Breakthrough assessment techniques like ACT, paired with 40 years of reference data allows us to offer advice that is as precise as it is bespoke, solving the challenges associated with PFAS removal.
Adsorbtion, reactivation, repeat: What makes some activated carbons a ‘safe sink’ for PFAS?
Activated carbons are already valued as one of the most effective filtration mediums for industrial wastewater treatment, capable of capturing a broad range of contaminants both synthetic and organic. What’s less well-known however, is how certain specially produced activated carbons are highly effective in removing PFAS from water and— through thermal reactivation— ensuring these adsorbed contaminants are mineralised and destroyed.
Bituminous-coal-based, reagglomerated activated carbons have been shown to effectively remove both long and short chain PFAS molecules to well below mandated limits from an array of different wastewater types. Offering the performance of purpose-built filtration systems with the convenience, flexibility and lower capital expenditure of leased equipment, our tailored CYCLESORB® mobile carbon filters are equipped to tackle a broad range of flow rates and pollutant levels, no matter how remote the location. Once the activated carbons containing PFAS are saturated, they are then thermally reactivated in our high-temperature furnaces, destroying the adsorbed contaminants via mineralization. This allows the activated carbon to be reused in the same application with similar performance. It’s this high-quality activated carbon, equipped with the capacity for effective reactivation, that makes the Chemviron’s CYCLESORB® mobile carbon filter service a true ‘safe sink’ solution for PFAS removal. With our 360° service, these ‘forever chemicals’ are not simply moved from one place to another, but mineralised and destroyed by thermal reactivation, helping keep operations compliant now, and into the future.
Take action on PFAS with Chemviron
Navigating the practicalities of PFAS treatment can be complex, and that’s why you need more than just a solutions provider. At Chemviron, we strive to be your PFAS filter, cutting through the noise with tailored advice and industry-leading activated carbon treatments designed for your unique needs. From our tried, tested and internationally recognised activated carbon technology offering, with its capacity for recycling by reactivation, to our convenient and cost-effective mobile carbon filters, we help you take real action against PFAS and safeguard your operations now, and well into the future.
Ready to learn more? Contact our technical team today to get started on your PFAS removal journey.
