The U.S. Defense Advanced Research Projects Agency (DARPA) has announced the successful test of a mobile system that can neutralize large quantities of poison gas such as sarin, the chemical warfare agent (CWA) used against the population of the Syrian town of Khan Shaykhun last April 4 by Bashar al-Assad's air force.
The secret to the successful field test is a novel waterless soil-scrubbing technology that safely neutralized toxic chemicals simulating sarin, soman and mustard agents.
Developed under DARPA's Agnostic Compact Demilitarization of Chemical Agents (ACDC) program, the technology demonstrated more than 99.9999% removal of the test CWAs without creating any hazardous waste by-products.
The soil-scrubbing technology was tested in conjunction with the Tactical Plasma Arc Chemical Warfare Agents Destruction System (PACWADS), a thermal treatment system already under development for use by the U.S. military.
PACWADS uses a high-temperature plasma torch to convert highly toxic chemicals into relatively benign components, and then uses a water-based capture process to eliminate the last traces of contaminants.
For the ACDC experiment, PACWADS was modified to eliminate the water scrubber and connect instead to DARPA's soil-based scrubber system, which captured and converted the toxic CWA decomposition products and resulting acid gases into non-hazardous salts.
An ability to use local soil from the site where CWA stores have been discovered eliminates the logistical burden of supplying water to such sites. These sites will likely be remote, and there's the problem of having to transport resulting liquid wastes to a treatment facility.
The soil used in the DARPA process remains non-hazardous and could be safely returned to the environment.
"We were very impressed with fast work by DARPA-supported researchers to develop the soil-based scrubber to test with the PACWADS," said Tyler McQuade, DARPA program manager.
"These successful tests validated a critical component of the ACDC concept -- a water-free, non-hazardous, soil-based process for onsite destruction of deadly chemicals. We now look forward to testing the ACDC scrubber with the PACWADS against actual chemical warfare agents in the coming months."