Neutralization of chemical warfare agents with air and light
Researchers at CiTOS (Center for Integrated Technology and Organic Synthesis, MolSys Research Unit) of ULiège have developed an innovative, compact and mobile process for the neutralization of mustard gas simulant that relies just on air and light.and high tech fluidic reactors. Having a small footprint, this neutralization technology can be embarked on a vehicle for on-site interventions and/or located in a neutralization installation. This research has been published in the journal Green Chemistry(1).
Mustard gas (1-chloro-2-[(2-chloroethyl)sulfanyl]ethane, HD) is a chemical warfare agent with cytotoxic and extremely highly vesicant properties. This compound, infamously known for its use during World War I (WWI), and more recently during the Iran-Iraq conflict, comes in the form of a colourless and odorless liquid in its purest form , which causes severe skin, mucous membranes and respiratory tract cburns. Its name "mustard" comes from smell of its impure form that resembles mustard. Its manufacture, storage and use are prohibited since the 1997 Chemical Weapons Convention (CWC). Nevertheless, large stockpiles of HD remain around the world, both in the form of intact stockpiles and spoiled remnants of armed conflict, which pose a potential threat. Reports from 2017-2018 in the Middle East attested of its use against civilians. Even more recent reports (2019) revealed large beds of spoiled WWI ammunitions in the North See, just miles off the Belgian coast, with significant potential for release. This compound is a threat not only to civilians, but also to emergency responders and military forces during neutralisation operations.
With a long expertise in the field of micro/mesofluidics, researchers at CiTOS (Research Unit Molsys/Faculty of Sciences) of the ULiège, have just developed a safe and compact fluidic platform for the neutralization of a mustard gas simulant with air and light. “We propose here an innovative, safe and rapidly deployable approach for the neutralization of mustard gas using a fluidic reactor," explains Jean-Christophe Monbaliu, director of CiTOS. This technology is based on the inherent properties of a high-tech fluidic reactor and on carefully optimized experimental conditions that are simple but robust."The neutralization protocol uses only widely available, inexpensive and non-toxic chemicals. It exploits the oxidizing power of an activated oxygen species (singlet oxygen), which is generated in situ from the synergistic effects of light and an organic photosensitizer in the presence of oxygen from the air.
The development of this technology is in line with the Organization for the Prohibition of Chemical Weapons' (OPCW) commitment to promote green and sustainable chemistry. The lead authors, Noémie Emmanuel and Pauline Bianchi with CiTOS, under the direction of Jean-Christophe M. Monbaliu, developed this process in close collaboration with Dr. Julien Legros of the University of Normandy (UNIROUEN).
" The aspects of safe, frugal, and low environmental footprint for the neutralization of chemical warfare are very unique and will potentially attract a lot of attention not only from military research facilities, but also from the general chemistry and chemical engineering communities, as well as the public at large since it tackles a current societal challenge." explains Jean-Christophe Monbaliu. “We are now extending such neutralization protocol to other chemical warfare agents”
Scientific reference
N. Emmanuel, P. Bianchi, J. Legros et J.-C. M. Monbaliu, A safe and compact flow platform for the neutralization of a mustard gas simulant with air and light, Green Chem., May 2020.
Funding
This work was supported by the French Community of Belgium (Concerted Research Action ARC-icFlow, Integrated Continuous Flow Photoreactors).
