Supercritical Water PFAS Destruction Plant Starts.

[NNadir]

PFAS DESTRUCTION USING SUPERCRITICAL WATER

The presence of per- and polyfluoroalkyl substances (PFAS) in wastewater and groundwater has garnered increased attention as a health and environmental issue because of their recalcitrance and bioaccumulation. To complement existing PFAS separation technologies, the Battelle Memorial Institute (Columbus, Ohio; www.battelle.org) has developed a technology, known as the PFAS Annihilator, for destroying both short- and long-chain PFAS compounds using supercritical water oxidation (SCWO). This month, the first on-site deployment of the technology has begun at a wastewater treatment plant.

Above its critical point (>374°C and >221 bars), water has both liquid and gas properties. The Battelle process uses water around these temperatures and pressures to mineralize a wide range of PFAS species. This new SCWO technology is related to similar processes used previously to destroy polychlorinated biphenyls (PCBs), but now has been optimized to destroy PFAS molecules.

In the process (diagram), an oxidant is introduced into the supercritical water reactor, and a base (NaOH) is added to neutralize the hydrofluoric acid formed by the reactions. The PFAS Annihilator has demonstrated the ability to destroy 99.99% of total PFAS in various aqueous feeds, Battelle says, leaving inorganic salts, such as NaF and Na2SO4, as inert end-products...

Cool.

This PFAS problem is a big one. I note that SCWO (Supercritical Water Oxidation) will also destroy microplastics by gasifying them.

[lapfog_1]

1. ok, I'll bite, just how many of these do we need to almost eliminate PFAS

from the world. I'm guessing that just processing drinking water isn't enough because these chemicals are, as the article states, bioaccumulaters.

I won't ask for complete elimination as that is highly unlikely.

Do they make any estimates?

[NNadir]

2. I personally believe that we need to utilize a continuous flow network of natural waters...

...including seawater to accomplish this task.

The PFAS problem is huge and diffuse. This contaminant is basically everywhere.

An interesting property of supercritical water is that most inorganic salts are insoluble in it. Thus, carefully utilized, supercritical water systems can also function as desalination systems, with the expansion of the supercritical water into steam being utilized either for process heat or for Rankine type generators.

I will not live to see this, but I have shared these ideas with my son who will begin his Ph.D. research in Nuclear Engineering this August.

It is possible to convert power plants that now degrade the air and the water to purify the air and the water in a series of continuous flow multi-task heat networks.

The plant described in the OP is almost certainly heated using dangerous fossil fuels, which is, in my view, unacceptable.