Inhibition of soil microbial activity by nitrogen‐based energetic materials

Abstract

We investigated individual toxicities of the nitrogen-based energetic materials (EMs) 2,4-dinitrotoluene (2,4-DNT); 2-amino-4,6-dinitrotoluene (2-ADNT); 4-amino-2,6-dinitrotoluene (4-ADNT); and nitroglycerin (NG) on microbial activity in Sassafras sandy loam (SSL) soil, which has physicochemical characteristics that support very high qualitative relative bioavailability for organic chemicals. Batches of SSL soil for basal respiration (BR) and substrate-induced respiration (SIR) assays were separately amended with individual EMs or acetone carrier control. Total microbial biomass carbon (biomass C) was determined from CO production increases after addition of 2500 mg/kg of glucose-water slurry to the soil. Exposure concentrations of each EM in soil were determined using US Environmental Protection Agency method 8330A. Basal respiration was the most sensitive endpoint for assessing the effects of nitroaromatic EMs on microbial activity in SSL, whereas SIR and biomass C were more sensitive endpoints for assessing the effects of NG in soil. The orders of toxicity (from greatest to least) were 4-ADNT > 2,4-DNT = 2-ADNT > NG for BR; but for SIR and biomass C, the order of toxicity was NG > 2,4-DNT > 2-ADNT = 4-ADNT. No inhibition of SIR was found up to and including the greatest concentration of each ADNT tested in SSL. These ecotoxicological data will be helpful in identifying concentrations of contaminant EMs in soil that present acceptable ecological risks for biologically mediated processes in soil. Environ Toxicol Chem 2017;36:2981-2990. Published 2017 Wiley Periodicals Inc. on behalf of SETAC.This article is a US government work and, as such, is in the public domain in the United States of America.

H2-Based Membrane Catalyst-Film Reactor (H2-MCfR) Loaded with Palladium for Removing Oxidized Contaminants in Water

“…Oxidized contaminants include a broad spectrum of inorganic oxyanions and halogenated and/or nitrated organics. They commonly occur in groundwater and municipal, industrial, and mining wastewaters. , Their risks to human and ecosystem health also are wide-ranging and well-recognized. ,, Maximum contamination levels (MCLs) for many oxidized contaminants have been mandated by the United States Environmental Protection Agency (US EPA)…”

“…1,2 Their risks to human and ecosystem health also are wide-ranging and well-recognized. 1,3,4 Maximum contamination levels (MCLs) for many oxidized contaminants have been mandated by the United States Environmental Protection Agency (US EPA). 5 Transition-metal catalysts offer distinctly high efficiency for reducing oxidized contaminants with controllable activity and selectivity.…”