Publications by authors named "J Hawari"

Exposure to toxic metals from nonferrous metal(loid) smelter soils can pose serious threats to the surrounding ecosystems, crop production, and human health. Bioremediation using microorganisms is a promising strategy for treating metal(loid)-contaminated soils. Here, a native microbial consortium with sulfate-reducing function (SRB1) enriched from smelter soils can tolerate exposures to mixtures of heavy metal(loid)s (e.

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The explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) is of particular interest due to its extreme insensitivity to impact, shock and heat, while providing a good detonation velocity. To determine its fate under environmental conditions, TATB powder was irradiated with simulated sunlight and, in water, under UV light at 254 nm. The hydrolysis of particles submerged in neutral and alkaline solutions was also examined.

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The present study investigates the bioaccumulation of the insensitive munition compounds 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO), developed for future weapons systems to replace current munitions containing sensitive explosives. The earthworm Eisenia andrei was exposed to sublethal concentrations of DNAN or NTO amended in Sassafras sandy loam. Chemical analysis indicated that 2- and 4-amino-nitroanisole (2-ANAN and 4-ANAN, respectively) were formed in DNAN-amended soils.

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The photolysis of bis(1-tetrazol-5-yl)amine (HBTA) in water was carried out in SolSim and Rayonet photochemical reactors equipped with solar simulating and ultraviolet lamps, respectively. The intermediary degradation products were monitored and tentatively identified by liquid chromatography - mass spectrometry (LC-MS). A quadrupole time-of-flight mass spectrometer (QTOF) was used to measure the mass-to-charge ratio () of the deprotonated molecular ions ([M - H]) using electrospray ionization in negative mode (ESI-), thus making it possible to determine the number of C, H, N and O in the molecules.

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Tetrazoles have wide industrial applications, notably in the pharmaceutical industry. Tetrazole derivatives such as bis(1H-tetrazol-5-yl)amine (HBTA) have recently been considered by the defense industry as high nitrogen composite propellants. Photodegradation studies under solar simulating conditions showed that HBTA was partially degraded in water, while it was completely degraded under UV light at 254 nm.

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