A Kinetic Model for Cathodic Degradation of Explosives in a Flow-Through Electrochemical Reactor

A laboratory-scale, flow-through, undivided cell electrochemical reactor hosting a stainless steel wire mesh cathode and downstream Ti/MMO anode was evaluated for its ability to degrade the dissolved explosives with diverse chemical properties and reactivities. Degradation efficiencies of RDX, NQ, DNAN, MNA, 2,4-DNT, HMX, TNT, and NTO were dependent on applied current, and 80-100% removal efficiency was achieved after a ~5.5 min detention time. A kinetic model was developed for explosives degradation along the cathode distance considering the processes of explosives reduction at the cathode surfaces, possible alkaline hydrolysis, and mass transfer limitations on cathodic reduction rates. Accordingly, intrinsic reaction rate coefficients for were derived, and their values ranged two orders of magnitude. Rate coefficients for the nitroaromatics increased as MNA<2,4-DNT