Degradation and fate of 2,4-dinitroanisole(DNAN)and its intermediates treated with Mg/Cu bimetal:Surface examination with XAS,DFT,and LDI-MS  

作　　者：Andrew Mai Emese Hadnagy Qiantao Shi Lotanna Ezeonu Jason P.Robbins Simon G.Podkolzin Agamemnon Koutsospyros Christos Christodoulatos 

机构地区：[1]Center for Environmental Systems,Stevens Institute of Technology,Hoboken,NJ 07030,USA [2]School of Engineering and Technology,University of Washington Tacoma,Tacoma,WA 98402,USA

出　　处：《Journal of Environmental Sciences》2023年第7期161-173,共13页环境科学学报（英文版）

基　　金：This work was supported by the Army Corps of Engineers,Industrial Base Resilience Initiative under Contract No.:W91278-16-D-0007,Delivery Order W9127820F0125.

摘　　要：A novel Mg-based bimetal reagent(Mg/Cu)was used as an enhanced reductive system to degrade insensitivemunition 2,4-dinitroanisole(DNAN),a contaminant found in energeticladenwaste.Degradation ofDNANwas significantly impacted by dissolved oxygen and studied in anoxic and oxic bimetal systems(i.e.,purging with N2,air,or O_(2) gas).Degradation occurred through sequential nitroreduction:first one nitro group was reduced(ortho or para)to form short-lived intermediates 2-amino-4-nitroanisole or 4-amino-2-nitroanisole(2-ANAN or 4-ANAN),and then subsequent reduction of the other nitro group formed 2,4-diaminoanisole(DAAN).The nitro-amino intermediates demonstrated regioselective reduction in the ortho position to 2-ANAN;Regioselectivity was also impacted by the anoxic/oxic environment.Under O_(2)-purging DNAN degradation rate was slightly enhanced,but most notably O_(2) significantly accelerated DAAN generation.DAAN also further degraded only in the oxygenated Mg/Cu system.Adsorption of DNAN byproducts to the reagent occurred regardless of anoxic/oxic condition,resulting in a partition of carbon mass between the adsorbed phase(27%-35%)and dissolved phase(59%-72%).Additional surface techniqueswere applied to investigate contaminant interaction with Cu.Density functional theory(DFT)calculations identified preferential adsorption structures for DNAN on Cu with binding through two O atoms of one or both nitro groups.X-ray absorption spectroscopy(XAS)measurements determined the oxidation state of catalyticmetal Cu and formation of a Cu-O-N bond during treatment.Laser desorption ionization mass spectrometry(LDI-MS)measurements also identified intermediate 2-ANAN adsorbed to the bimetal surface.

关 键 词：Insensitive munition Magnesium bimetal Reductive degradation Adsorption Surface analysis DFT DNAN Oxic 

分 类 号：X703[环境科学与工程—环境工程]