A lot of discussion around PFAS has focused on how to remove it from the natural environment. There are good reasons for this – the environmental and human health case against PFAS is growing.
For example, The Guardian continued its reporting last year about a lawsuit against the chemical giant DuPont, which led to DuPont settling 3,500 personal injury cases in 2017 for $670.1 million. These cases were widely publicized in the Hollywood biopic Dark Waters.
The Guardian said of a study related to this legal case: “(This study) which ran between 2005 and 2013, involving the collection of blood samples from about 69,000 people living near the DuPont plant (in Parkersburg WV), concluded that there was a “probable link” between exposure to PFOA and six diseases: high cholesterol, ulcerative colitis, thyroid disease, testicular cancer, kidney cancer and pregnancy-induced hypertension.”
So, what’s next for these manufactured chemicals, formally called Per-and Polyfluoroalkyl Substances?
The PFAS problem starts with concentration, but can’t end there
Part of the problem with PFAS is that it can cause health and environmental problems at low doses – in the parts per trillion range. Another problem is that PFAS is so widely spread at those concentrations, because these useful chemicals are found in so many products.
This makes the PFAS problem a two-stage solution – first, to pull these low concentrations of PFAS together so that they can be dealt with cost-effectively; and second, to destroy the PFAS molecules – break them down into harmless atoms and molecules.
In a previous post, we talked about three main tools for concentrating PFAS. Briefly:
- Foam fractionation: releasing bubbles of air from the water to be treated – PFAS molecules attach themselves to the gas-liquid interface of the bubbles, to form a PFAS-rich foam that can be skimmed off.
- Ion exchange: The internal surfaces of highly porous, polymeric materials are positively charged, attracting the negatively-charged PFAS molecules.
- Reverse osmosis: Pumps push PFAS-containing liquid against a semi-permeable membrane; water molecules are small enough to slip through the membrane, while larger PFAS molecules (and other contaminants) stay on the “concentrate” side.
What these three technologies and other concentration methods have in common, is that they produce two streams – water from which PFAS has been removed, and a liquid that contains PFAS.
Then the question becomes: what to do with the PFAS concentrate? Some advocate landfills as the best place for PFAS-containing waste (fast-food wrappers, non-stick cookware, and others) as well as PFAS-impacted soil, and PFAS concentrate. But the problem is leachate – precipitation that flows through the landfill, picking up problematic constituents including PFAS, along the way. Then, once again, we have a PFAS problem – how to treat the leachate so that it doesn’t form another way for PFAS to disperse.
Just leaving the problem to future generations isn’t good enough. We need an effective way to break up the PFAS molecules to render them harmless. But PFAS molecules are designed to be invincible – the carbon-fluorine bond they contain is one of the strongest known to chemical science. It’s like trying to crush a diamond in your hand.
We need to find the “missing link” between PFAS concentrate and a PFAS-free end product.
What does a PFAS destruction technology need to look like?
Part of the solution to destroying PFAS molecules comes from imagining what a successful technology needs to look like. To be workable, a PFAS destruction solution must include:
Standard temperatures and pressures: maintaining high temperatures is financially and environmentally costly. High pressures are also costly to maintain, and with high pressures (think boilers) comes the risk of a catastrophic explosion. So, technologies that work at standard temperatures and pressures are ideal.
Proven technology: While leading-edge technologies are good to have, it’s more important that the technology is shown to work. This boosts reliability. It also means that components are readily available from a range of suppliers, making them low-cost and reliable.
Low operating cost (OpX) and capital cost (CapX): Because the PFAS problem is so widespread – for example, many landfills contain PFAS and produce PFAS-laden leachate – the solution for destroying PFAS must be low-cost to buy and to operate. Bonus points if the technology can be operated by relatively unskilled labor.
Scaleable: An effective PFAS-busting technology must work at small scale – small enough for a homeowner to keep their well-water free from PFAS – to something big enough to keep PFAS out of the effluent of a large landfill.
As you might imagine, we believe that Onvector’s Plasma Vortex technology fits the bill – working at standard temperatures and pressures, proven technology, low OpX and CapX, and scalable. Contact us to discuss how we can help you solve your PFAS destruction problem.