VICKSBURG, Miss.—A multi-faceted compound that not only produces color changes when added to various Military munition concentrations is also capable of absorbing these dangerous participles for removal, thanks to precise processes invented by the Environmental Laboratory (EL) team at the U.S. Army Engineer Research and Development Center (ERDC.)
With research beginning in 2016, the “In situ testing apparatus for detecting and removing munitions compounds from water” received its U.S. Patent in May 2021. EL’s invention team for environmental improvements was led by Luke Gurtowski and Dr. Chris Griggs, both of Vicksburg, along with David Martin and Manoj Shuka, both of Clinton, Mississippi.
Gurtowski is a research chemical engineer, and Griggs is a research physical scientist. Both work in the EL’s Environmental Engineering Branch, which focuses on the development of materials from earth-abundant biopolymers, such chitin, chitosan and cellulose. These biopolymers couple with nanoscale materials to address water security, advanced water treatment, emerging contaminants and other complex challenges facing the nation’s natural environment.
“There is an unmet need for a compound produced at scale to efficiently remove munitions from underground water supplies, lakes, rivers and oceans,” Gurtowski explained about the basis for the EL research project.
Containing organic explosive compounds and various metals, these munitions pollute marine waters, terrestrial systems and ground water. Many munitions originated in World War II, resulting in decades of extensive corrosion, while current water-column releases can cause sorption, the action where one substance gets attached to another as a sponge dipped in water.
He added that “the military would be the primary customer for this material. Specifically, military and civilian personnel responsible for environmental treatment or chemical detection will use the material,” Gurtowski added. “The material could be used at Army ranges or in theater in areas where munitions could be detonated. Furthermore, the staff at Army Ammunition Plants could use the material for testing and treatment when preparing munitions for training and deployment.”
Clean-up in the billions
Munitions can contaminate soils and waters in areas where they are used, and the Department of Defense estimates clean-up operations can amount to billions of dollars.
“Munitions’ compounds are potentially toxic to humans and wildlife, making munitions’ detection and removal essential to minimize damage to the Military and surrounding communities,” said Gurtowski, who serves as team leader and with expertise in water treatment, materials development, nanomaterials, adsorption, analytical methodology and emerging contaminant management.
The team conducted this research because of the existing knowledge gap related to interactions between munitions’ compounds and biopolymers. Evaluations were conducted with various commercial off-the-shelf biopolymers, including cellulose, cellulose acetate, chitin and chitosan, to determine if sorption would occur when these materials were exposed to emerging insensitive munitions.
“Assessing these experiments, we conducted computational modelling to determine functionalization capabilities for chitin, the world’s second-most abundant biopolymer, for further analysis. Then, our ERDC team produced amine-functionalized chitin to comprise the patented testing apparatus for munitions detection and removal,” Gurtowski said.
How it works and uses
Gurtowski explained that the system includes a delivery component, (a material or container), with an amine-functionalized chitin (AFC) compound to interact with a water sample or a mixture of solids suspended in liquid, such as soil particles in water.
Standard munitions compounds, such as Nitrotriazolone (NTO), 2,4-dinitroanisole (DNAN), and trinitrotoluene (TNT), contaminate soil and groundwater, and both are acutely and chronically toxic. They are also resistant to natural microbiological degradation and negatively affect ecosystems even at low levels.
The AFC compound produces a color change correlated with the presence and concentration of munitions, for example, in a transparent receptacle, or added to a paper or fabric test strip. Upon detection of at least a one part per million (ppm) concentration of NTO, DNAN or TNT, a solid pale-yellow organic nitrogen compound used chiefly as an explosive, the munitions are absorbed by the AFC compound, and a filter with a pore size of 0.45 microns captures and removes the particles. Color changes begin immediately upon detection and reach the final color after 24 hours, Gurtowski said.
In fiscal year 2022, the leaders from the ERDC Office of Research and Technology Transfer will recognize the EL team with individual inventor awards at the enterprise headquarters in Vicksburg. For technical information, visit the patent application link: https://patents.justia.com/patent/20190118162.