Biodegradation of Unsymmetrical Dimethylhydrazine in Solution and Soil by Bacteria Isolated from Activated Sludge

Abstract

The biodegradation effect and pathway of unsymmetrical dimethylhydrazine (UDMH), which is a major rocket propellant with highly toxic properties, with two strains isolated from the acclimated activated sludge were investigated in solution and in soil. The results demonstrated that Stenotrophomonas sp. M12 (M12) was able to degrade UDMH of 50 mg¨L´1 as the sole carbon source in aqueous mineral salt medium (MSM), but could not degrade UDMH in soil. Comamonas sp. P4 (P4) barely degraded UDMH of 50 mg¨L´1 as the sole carbon source in aqueous MSM, but the degrading capacity of P4 could be improved by the addition of an extra carbon source. Meanwhile, P4 was able to degrade UDMH of 100-600 mg¨kg´1 in the soil. The degradation of UDMH in the soil was influenced by organic matter, autochthonous microorganisms, and metal ions. UDMH could inhibit metabolism of M12 and P4, and the inhibition influence was more severe in aqueous MSM than in soil. Oxygen content was important for M12 biodegrading UDMH, and co-metabolism helped P4 to self-detoxify and self-recover. The main intermediates of UDMH were identified by Gas Chromatography-Mass Spectrometer (GC/MS) qualitative analysis, and the concentrations of UDMH and its important transformation products were determined in solution and soil. According to the determination results, the synchronous degradation theory was proposed, and the degradation pathway was discussed.

Photocatalytic degradation of unsymmetrical dimethylhydrazine on TiO2/SBA-15 under 185/254 nm vacuum-ultraviolet

“…To date, several conventional technologies have been attempted to remove UDMH. Liao et al 4 reported bacteria belonging to Stenotrophomonas sp. and Comamonas sp.…”

Quantification of transformation products of rocket fuel unsymmetrical dimethylhydrazine in air using solid‐phase microextraction

“…After launch, burned‐out rocket stages fall at the distance ≤1500 km from a launchpad [2], such as Baikonur (Kazakhstan), resulting in contamination of the environment with ≤4 tons of unburned fuel [3–5] in the case of a successful launch and ≤600 tons in the case of an accident [6]. Under the effect of NO 2 , oxygen, sunlight, elevated temperatures, biota, soil, and water constituents [7–9], UDMH transforms into a number of potentially dangerous substances – amines, nitrosoamines, triazoles, pyrazoles, and amides [10,11]. Among all known UDMH transformation products (TPs), the most studied are amines, nitrosoamines, and formamides [12–15].…”