Functionalized Nano-Fiber Mats as Super-Adsorbents for Explosive Substances
Abstract
Production, use and recalcitrance of explosives such as nitre-explosives over a long period, have led to their environmental persistence, which is a serious concern. The contamination by explosives, or land as well as marine and ground water, occurs mainly by efnuents from explosive manufacturing plants. The nitre-explosives, as well as their intermediate products, are highly toxic to living organisms, inducing an array of disorders, including symptoms or methcmoglobinemia, kidney malfunction. and jaundice in humans. Therefore, it is necessary to remove these compounds from the wastewater. Various methods arc currently used for remediation of nitroaromatic explosives: physical, chemical and biological. Biological methods are not cost-effective nor environmentally friendly, considering that a single TNT manufacturing plant can generate a few mega liters of waste waters per day. Therefore. a combination of chemical and physical methods employing coagulation. flocculation, filtration and adsorption, are preferred over biological methods. The purpose of this research is to reduce the amount of explosive residues, such as RDX and TNT, in water reservoirs afler major waste treatment. This is planned by using chitosan nano-structures (beads, and a nonwoven fibers mat). Chitosan is a natural polysaccharide that contains hydroxyl (OH) and amine (NH2) units positioned on its backbone. These functional groups can attract nitro explosives, such as TNT and RDX from water. In addition, it is assumed that the huge surface area (> 100 m2/g) of the chitosan nanostructures, and the penneability of the fibers mat, will facilitate highly emcient contaminated fluid absorption and TNT/RDX adsorption. In this work, the first plan to optimize the geometry and topology of the chitosan nano-structures, wh ich combines bead like objects and a nom,oven fibers mat. Then, we plan to study the adsorption kinetics of TNT and RDX as a function of the adsorbent surface area, concentration. pH and temperature. Quantitative results are planned using 1H NMR analyses of the extracted materials after adsorption on chitosan, and on direct weight measurements of explosives remaining after drying. The adsorption equilibrium isotherms of TNT from aqueous solutions onto chitosan will be studied. Field tests in several sites are planned. Finally, testing and evaluating adsorption capacity of the chitosan nano-structures in large scale systems arc planned.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510585
Entities
People
- Eyal Zussman
Organizations
- Army Contracting Command
- United States Army