Degradation of Pentaerythritol Tetranitrate (PETN) by Granular Iron

Abstract

Pentaerythritol tetranitrate (PETN), a nitrate ester, is used primarily as an explosive. It is of environmental concern, posing a threat to aquatic organisms with an estimated EC50 five times greater than that of RDX. This study evaluated the kinetics and products of PETN degradation in the presence of granular iron. PETN transformation in columns containing 100% granular iron and 30% iron mixed with 70% silica sand followed pseudo first-order kinetics, with average half-lives of 0.26 and 1.58 min, respectively. The reduction pathway was proposed to be sequential denitration, in which PETN was stepwise reduced to pentaerythritol with the formation of pentaerythritol trinitrate and pentaerythritol dinitrate as intermediates. The intermediate of pentaerythritol mononitrate was not detected; however, the nearly 100% nitrogen mass recovery supported complete denitration. Nitrite was released in each denitration step and was subsequently reduced to ammonium by iron. Nitrate was not detected during the experiment suggesting that hydrolysis was not involved in PETN degradation. Batch experiments showed that when solid-phase PETN is present, dissolution is the rate-limiting factorfor PETN mass removal. Using 50% methanol as a cosolvent PETN solubility was enhanced and thus the removal efficiency was improved. The results demonstrate excellent potential of using iron to remediate PETN-contaminated water.

Enhanced Aerobic Biodegradation of Soil Contaminated with Explosives (TNT and PETN) By Rhamnolipid

“…The drop in bacterial density very likely indicates that the rhamnolipid had been used up or environment condition have undergo change. [4] who, stated that the apparent absence of pentaerythritol mononitrate (PEMN) in the sequential denitration pathway may be due to the fact that the rate of PEMN to PE conversion was faster compare to its formation from PEDN and the low amount of PEMN, which resulting in the concentration being below the detection limit of HPLC analysis.…”

“…Penetration of these hazardous and toxic chemicals to the soilbysurfacerunofforleachingintogroundwater,led to contamination of streams and aquifers [3]. Among such compounds, 2,4,6-trinitrotoluene (TNT) and Pentaerythritol Tetranitrate (PETN) are the predominant contaminant at ammunition plants, testing facilities and military zones [2] [4].TNT is considered to be toxic for a wide range of aquatic species [5] [6], terrestrial organisms [1] mammals [5] and human monocytes [6]. In addition, TNT has been stated to have a mutagenic and carcinogenic potential in studies with several organisms [7].…”

“…In addition, TNT has been stated to have a mutagenic and carcinogenic potential in studies with several organisms [7]. EPA classified TNT as class C(possible human carcinogen).PETN is classified as a munitions constituent of greatest concern because of its extensive use and potential environmental impact [4] [6]. Furthermore, it was reported that shortterm exposure may affect the cardiovascular system [4].…”

“…EPA classified TNT as class C(possible human carcinogen).PETN is classified as a munitions constituent of greatest concern because of its extensive use and potential environmental impact [4] [6]. Furthermore, it was reported that shortterm exposure may affect the cardiovascular system [4]. Due to the risks related to nitroenergetic compounds, considerable attentions have been made to implement effective remediation and decontamination approaches in explosive-contaminated sites [9][10] [11].…”

Aging of Pentaerythritol Tetranitrate (PETN)

“…Another study evaluated the kinetics and products of PETN degradation in the presence of granular iron. [Zhuang 2008] The iron material contained 89.8% metallic iron with a surface layer of various forms of iron oxides. The degradation pathway was proposed to be sequential pseudo first-order kinetics denitration, in which PETN was stepwise reduced to pentaerythritol with the formation of pentaerythritol trinitrate (PETriN) and pentaerythritol dinitrate (PEDN or PEDiN) as intermediates.…”