湿法粉碎制备纳米RDX安全性分析与性能表征

从热传导理论分析入手,以回收的RDX为原料,选择易获取的水为导热介质,湿法粉碎制备了纳米级RDX样品。利用纳米激光粒度仪、场发射扫描电镜和卡斯特型落锤仪对样品粒径大小、外观特征、感度大小进行了观察和测试。实验结果表明,湿法制备的纳米级RDX感度明显降低,安全性提高。由于本方法成本低廉,使得大规模回收的RDX再次利用成为可能,解决了RDX不方便储存运输使用等难题,扩大了其使用范围。     

Age dependent acute oral toxicity of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and two anaerobic N-nitroso metabolites in deer mice (Peromyscus maniculatus)

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) transforms anaerobically into N-nitroso compounds: hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX). Exposure to these N-nitroso metabolites may occur in areas contaminated with explosives, as anaerobic degradation occurs via some bacteria and is one remediation strategy used for RDX. Few papers report acute oral toxicity and none have evaluated age dependent toxicity of RDX or its N-nitroso metabolites. Median lethal dose (LD₅₀) was determined in deer mice (Peromyscus maniculatus) of three age classifications 21 d, 50 d, and 200 d for RDX, MNX, and TNX using the US EPA up-and-down procedure (UDP). Hexahydro-1,3,5-trinitro-1,3,5-triazine and N-nitroso metabolites caused similar overt signs of toxicity. Median lethal dose for 21 d deer mice were 136, 181, and 338 mg/kg for RDX, MNX, and TNX, respectively. Median lethal dose for 50 d deer mice were 319, 575, and 338 mg/kg for RDX, MNX, and TNX, respectively. Median lethal dose for 200 d deer mice were 158, 542, and 999 mg/kg for RDX, MNX, and TNX, respectively. These data suggest that RDX is the most potent compound tested, and age dependent toxicity may exist for all compounds and could play a role in RDX and RDX N-nitroso metabolite ecological risk evaluation of terrestrial wildlife at RDX contaminated sites.     

Comparison of biotic and abiotic treatment approaches for co-mingled perchlorate, nitrate, and nitramine explosives in groundwater

Biological and abiotic approaches for treating co-mingled perchlorate, nitrate, and nitramine explosives in groundwater were compared in microcosm and column studies. In microcosms, microscale zero-valent iron (mZVI), nanoscale zero-valent iron (nZVI), and nickel catalyzed the reduction of RDX and HMX from initial concentrations of 9 and 1 mg/L, respectively, to below detection (0.02 mg/L), within 2 h. The mZVI and nZVI also degraded nitrate (3 mg/L) to below 0.4 mg/L, but none of the metal catalysts were observed to appreciably reduce perchlorate ( approximately 5 mg/L) in microcosms. Perchlorate losses were observed after approximately 2 months in columns of aquifer solids treated with mZVI, but this decline appears to be the result of biodegradation rather than abiotic reduction. An emulsified vegetable oil substrate was observed to effectively promote the biological reduction of nitrate, RDX and perchlorate in microcosms, and all four target contaminants in the flow-through columns. Nitrate and perchlorate were biodegraded most rapidly, followed by RDX and then HMX, although the rates of biological reduction for the nitramine explosives were appreciably slower than observed for mZVI or nickel. A model was developed to compare contaminant degradation mechanisms and rates between the biotic and abiotic treatments.     

Spectrophotometric analyses of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in water

A simple and accurate spectrophotometric method for on-site analysis of royal demolition explosive(RDX) in water samples was developed based on the Berthelot reaction. The sensitivity and accuracy of an existing spectrophotometric method was improved by:replacing toxic chemicals with more stable and safer reagents; optimizing the reagent dose and reaction time; improving color stability; and eliminating the interference from inorganic nitrogen compounds in water samples. Cation and anion exchange resin cartridges were developed and used for sample pretreatment to eliminate the effect of ammonia and nitrate on RDX analyses. The detection limit of the method was determined to be 100 μg/L. The method was used successfully for analysis of RDX in untreated industrial wastewater samples. It can be used for on-site monitoring of RDX in wastewater for early detection of chemical spills and failure of wastewater treatment systems.     

火炸药废水处理技术综述

火炸药废水问题已经成为世界性的环境污染问题.火炸药废水的处理技术主要包括物理技术、化学技术、生物技术以及各类技术的综合应用.根据国内外文献报道对各类技术进行了分类整理,分析了各类技术的优缺点及应用现状,推论出多种技术联合应用将是火炸药废水处理技术的发展趋势,并提出具体方案,为火炸药废水处理工艺的选择提供一定参考依据.     

The toxicity of soil samples containing TNT and other ammunition derived compounds in the enchytraeid and collembola-biotest

The effect of ammunition-like compounds and armament waste on the mortality and reproduction of terrestrial invertebrates was assayed by using two biotests: the enchytraeid-biotest withEnchytraeus crypticus and the collembola-biotest withFolsomia Candida. Toxicity was investigated by using standard soil (Lufa 2.2) spiked with 2,4,6-trinitrotoluene (TNT), hexahydro-l,3,5-trinitro-l,3,5-triazine (hexogen, RDX), octahydro-l,3,5,7-tetranitro-l,3,5,7-tetrazocine (octogen, HMX) and 2,4,6-triaminotoluene (TAT). Ecotoxicity was investigated with ammunition-contaminated soil material from the former ammunition plant “Tanne” at Clausthal-Zellerfeld (CTNTla) and the Brandplatz (incineration site) in Torgau-Elsnig (TETNT1a), Germany. TNT increased mortality and reduced reproduction of both test organisms corresponding to the concentrations used, whereas hexogen, octogen and TAT had no effect in the tested concentrations (1000-2000 mg/kg). From the two soil materials, TETNT1a was much more toxic than CTNT1a. The LC50(7d) in the enchytraeid-biotest was 570 mg TNT/kg and the EC50(28d) 369 mg TNT/kg soil material (dw). In the collembola-biotest the LC50(7d) was 185 mg TNT/kg and the EC50(28d) 110 mg TNT/kg soil matter (dw).     

不同粒度RDX的重结晶制备和机械感度研究

为研究RDX机械感度随其粒度大小的变化规律,采用微团化动态结晶方法和溶剂/非溶剂滴加重结晶方法制备出中位径d50分别为0.429μm,7.052μm,40.75μm的RDX颗粒,并采用粒度分析仪和扫描电子显微镜(SEM)对3种试样的粒度进行了表征.测定了3种试样的撞击感度(特性落高H50)和摩擦感度(爆炸概率)值.测试结果表明,撞击感度随粒度减小逐渐降低,并且在粒度降至亚微米级时最低.摩擦感度随粒度减小先升高再降低,而且粒度在亚微米时最为钝感.     

Sensitivity of submersed freshwater macrophytes and endpoints in laboratory toxicity tests

The toxicological sensitivity and variability of a range of macrophyte endpoints were statistically tested with data from chronic, non-axenic, macrophyte toxicity tests. Five submersed freshwater macrophytes, four pesticides/biocides and 13 endpoints were included in the statistical analyses. Root endpoints, reflecting root growth, were most sensitive in the toxicity tests, while endpoints relating to biomass, growth and shoot length were less sensitive. The endpoints with the lowest coefficients of variation were not necessarily the endpoints, which were toxicologically most sensitive. Differences in sensitivity were in the range of 10-1000 for different macrophyte-specific endpoints. No macrophyte species was consistently the most sensitive. Criteria to select endpoints in macrophyte toxicity tests should include toxicological sensitivity, variance and ecological relevance. Hence, macrophyte toxicity tests should comprise an array of endpoints, including very sensitive endpoints like those relating to root growth.     

Geochemical and microbiological processes contributing to the transformation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in contaminated aquifer material

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a potential human carcinogen, and its contamination of subsurface environments is a significant threat to public health. This study investigated abiotic and biological degradation of RDX in contaminated aquifer material. Anoxic batch systems were started with and without pre-aeration of aquifer material to distinguish initial biological RDX reduction from abiotic RDX reduction. Aerating the sediment eliminated chemical reductants in the native aquifer sediment, primarily Fe(II) sorbed to mineral surfaces. RDX (50 μM) was completely reduced and transformed to ring cleavage products when excess concentrations (2 mM) of acetate or lactate were provided as the electron donor for aerated sediment. RDX was reduced concurrently with Fe(III) when acetate was provided, while RDX, Fe(III), and sulfate were reduced simultaneously with lactate amendment. Betaproteobacteria were the dominant microorganisms associated with RDX and Fe(III)/sulfate reduction. In particular, Rhodoferax spp. increased from 21% to 35% and from 28% to 60% after biostimulation by acetate and lactate, respectively. Rarefaction analyses demonstrated that microbial diversity decreased in electron-donor-amended systems with active RDX degradation. Although significant amounts of Fe(III) and/or sulfate were reduced after biostimulation, solid-phase reactive minerals such as magnetite or ferrous sulfides were not observed, suggesting that RDX reduction in the aquifer sediment is due to Fe(II) adsorbed to solid surfaces as a result of Fe(III)-reducing microbial activity. These results suggest that both biotic and abiotic processes play an important role in RDX reduction under in situ conditions.     

固体推进剂含能颗粒粒度、形貌与感度特性的相关性研究

目的 研究推进剂含能固体颗粒粒度、形貌与感度特性的相关性。方法 采用激光粒度分析仪、扫描电镜、摩擦、撞击、静电感度仪、爆发点测定仪,对推进剂主要含能固体颗粒AP、RDX、AL的粒度及感度进行测试研究,考察不同规格粒度的AP、RDX的机械、静电及热感度,对AP、RDX、AL的混合物料也进行感度测试。结果 AP的摩擦、静电感度随着粒度的减小而增加。粗AP(40~60目、60~80目及100~140目)对撞击感度不敏感,对于粉碎细料(1~18μm),表现出一定的敏感性。热感度与粒度的关系,对于5 s爆发点,其结果均大于400℃。对于普通RDX,2种不同粒度的RDX对不同激源均表现出较高的敏感性,高品质RDX的感度特性明显优于普通RDX。AP、RDX、AL混合后,感度特性发生了一定的变化。结论 细料AP机械感度与热感度较高,RDX粒度越小,摩擦、撞击感度下降,3种粒度RDX的静电感度相当,AP、RDX和AL粉混合时仍保持较高的摩擦感度。