加速溶剂同时萃取和净化-气相色谱-三重四极杆串联质谱测定土壤和沉积物中8种多溴联苯醚

建立了土壤和沉积物中8种多溴联苯醚(PBDEs,BDE-28、BDE-47、BDE-99、BDE-100、BDE-153、BDE-154、BDE-183和BDE-209)加速溶剂同时萃取和净化-气相色谱-三重四极杆串联质谱(ASE-GC-MS-MS)的分析方法。通过优化加速溶剂萃取与弗罗里硅土在线净化和串联质谱多反应监测模式的条件,较好地去除基质干扰,并提高了三重四极杆串联质谱定性的准确性及定量的灵敏性。该方法采用改进的色谱柱能同时分析包括高溴代联苯醚BDE-209在内的8种PBDEs,其浓度范围为1～100 ng/mL(BDE-209为10～1 000 ng/mL),线性良好,线性回归系数均大于0.997。方法检出限为0.004～0.1 ng/g,方法回收率为75%～110%,方法精密度为2.4%～15.6%。适于批量处理土壤和沉积物中含有多组分痕量PBDEs的样品。     

不同气源压缩气体泡沫灭石油醚火灾性能比较

采用实验室压缩气体泡沫系统,通过缩尺油盘火试验,分别考察基于不同气源的压缩气体泡沫对于石油醚火灾的灭火性能,分析探讨适用于低沸点的石油醚类燃料火灾扑救的气源类型和供气方案。结果表明,在泡沫溶液供给强度为2.5 L/(min·m2)的条件下,压缩氮气泡沫和压缩空气泡沫均可扑灭石油醚火灾,具有良好的抗烧性能;二者相比,压缩氮气泡沫比压缩空气泡沫的控灭火性能和抗烧性能均有一定提升;对于石油醚类的低沸点易燃液体火灾,建议采用以氮气作为气源的压缩氮气泡沫系统;该研究可为压缩气体泡沫系统在石油化工行业工程应用提供技术支撑。     

Debromination of decabromodiphenyl ether by organo-montmorillonite-supported nanoscale zero-valent iron：Preparation, characterization and influence factors

An organo-montmorillonite-supported nanoscale zero-valent iron material(M-NZVI) was synthesized to degrade decabromodiphenyl ether(BDE-209). The results showed that nanoscale zero-valent iron had good dispersion on organo-montmorillonite and was present as a core-shell structure with a particle size range of nanoscale iron between 30–90 nm, characterized by XRD, SEM, TEM, XRF, ICP-AES, and XPS. The results of the degradation of BDE-209 by M-NZVI showed that the efficiency of M-NZVI in removing BDE-209 was much higher than that of NZVI. The efficiency of M-NZVI in removing BDE-209 decreased as the pH and the initial dissolved oxygen content of the reaction solution increased, but increased as the proportion of water in the reaction solution increased.     

杭州市办公场所室内空气中PBDEs的污染现状与特征

分析评价了杭州市办公场所中PBDEs的污染现状、污染特征.结果表明,办公场所中PBDEs气相和颗粒相总浓度范围为40.66~141.00 pg·m-3,平均浓度为93.22 pg·m-3,是家庭室内、室外浓度的1.87、5.01倍.BDE-47、BDE-99为办公场所中最重要的两种同系物,分别占总浓度的33.29%、31.99%.PBDEs气相浓度是颗粒相的1.34倍,其中BDE-28、BDE-47、BDE-99主要存在于气相中,BDE-153、BDE-183主要存在于颗粒相中.     

2,2'',4,4''-四溴联苯醚对赤子爱胜蚓的抗氧化酶、代谢酶及其基因表达的影响

多溴联苯醚(PBDEs)是广泛存在于环境中的一种新型持久性有机污染物.四溴联苯醚同分异构体中的BDE-47是多溴联苯醚中最重要的单体之一.试验采用人工土壤培养法,通过亚急性试验,研究了在不同暴露时间阶段下,不同BDE-47剂量对赤子爱胜蚓(Eisenia fetida)抗氧化酶(过氧化氢酶CAT)、代谢酶(谷胱甘肽转移酶GST)以及二者基因表达的影响.结果表明,在暴露14 d和28 d时,CAT活性被诱导上升并且差异显著;GST活性变化差异不显著;CAT基因表达水平在第14 d时呈现抑制效应,在后续的第28 d和第42 d基因表达水平上调;GST基因表达水平整体呈现诱导效应,并且差异显著,随着暴露时间的增加,低毒处理组(10、50 mg·kg-1)的基因表达水平逐渐下调至低于对照组的水平,高毒处理组(100、200 mg·kg-1)的基因表达量仍高于对照组水平;在BDE-47的暴露试验中,CAT与GST活性及其基因表达水平两项指标对低毒处理组较高毒处理组更为敏感.     

PBDEs的来源特征、环境分布及污染控制

多溴联苯醚(Polybrominated diphenyl ethers,PBDEs)生产应用、环境分布与生态风险之间的关系将如何影响我国的未来,具体涉及到工业、环境、健康、人类繁衍等的社会问题.由于PBDEs阻燃效率高,热稳定性好,价格便宜,作为添加剂被广泛应用在电子、电器、化工、交通、建材、纺织、石油等领域的阻燃产品中.PBDEs进入环境后迁移扩散并富集于沉积物和生物体内,进入人体后引起肝脏毒性、内分泌干扰、神经毒性和生育能力下降等而危害人类的健康.基于此,从生产应用、品种生产量、分子的物理化学特性以及毒性等的文献数据分析了PBDEs的来源特征与环境危害,分析这些性质对环境分布与污染控制的基础支持关系;从沉积物、水体、大气、水生生物、人体5个方面考察了PBDEs的环境本底浓度变化、分配关系、迁移规律、时间效应,分析了生产、应用与扩散的多因素影响关系,发现全球性PBDEs污染物蔓延的现象,沉积物是主要的归趋场所,室内空气中的浓度远高于室外,水中浓度较低,水生生物和人体均能富集PBDEs,通过饮食、母乳和呼吸摄入,可实现代际传播,污染的分布呈现介质与区域的不同特征;污染控制需要考虑点源技术与面源修复的联合,结合PBDEs的物理性质、分子结构及其化学特性,统计分析了微生物法、光化学降解法和零价铁还原法的原理及其有效性,根据PBDEs在产品中存在与分布的特点,提出收集-分离-富集-超临界催化还原和氧化毁毒的工艺,针对实际环境(以电子垃圾塑料和流域水体及沉积物为对象)中的PBDEs进行回收或处理,结合材料如催化剂的应用,从动力学和热力学方面提高PBDEs无害化的效率.最后,从生产管理、环境监测、风险评价、技术集成等方面提出了未来的努力方向.     

Enhanced debromination of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) by zero-valent zinc with ascorbic acid

• Highly efficient debromination of BDE-47 was achieved in the ZVZ/AA system. • BDE-47 debromination by the ZVZ/AA can be applied to a wide range of pH. • AA inhibits the formation of (hydr)oxide and accelerates the corrosion of ZVZ. • Reduction mechanism of BDE-47 debromination by the ZVZ/AA system was proposed. A new technique of zero-valent zinc coupled with ascorbic acid (ZVZ/AA) was developed and applied to debrominate the 2,2′,4,4′-Tetrabromodiphenyl ether (BDE-47), which achieved high conversion and rapid debromination of BDE-47 to less- or non-toxic forms. The reaction conditions were optimized by the addition of 100 mg/L ZVZ particles and 3 mmol/L AA at original solution pH= 4.00 using the solvent of methanol/H₂O (v:v= 4:6), which could convert approximately 94% of 5 mg/L BDE-47 into lower-brominated diphenyl ethers within a 90 min at the ZVZ/AA system. The high debromination of BDE-47 was mainly attributed to the effect of AA that inhibits the formation of Zn(II)(hydr)oxide passivation layers and promotes the corrosion of ZVZ, which leads to increase the reactivity of ZVZ. Additionally, ion chromatography and gas chromatography mass spectrometry analyses revealed that bromine ion and lower-debromination diphenyl ethers formed during the reduction of BDE-47. Furthermore, based on the generation of the intermediates products, and its concentration changes over time, it was proposed that the dominant pathway for conversion of BDE-47 was sequential debromination and the final products were diphenyl ethers. These results suggested that the ZVZ/AA system has the potential for highly efficient debromination of BDE-47 from wastewater.     

Comprehensive Environmental Investigation at Former Industrial/Petroleum Underground Storage Tank Sites in Long Beach,CA: A Forensic Perspective

Two industrial sites were investigated based on years of available hydrogeologic information and monitoring data for soil and groundwater. Collected data were forensically evaluated using age-dating and fingerprinting methods. The previous business uses of the project sites were as a gas station, laundry/dry-cleaning service, and car wash with petroleum underground storage tanks (USTs). As a result, these sites were exposed to a number of toxic contaminants at relatively high concentrations. Source control was necessary for successful remediation and the ultimate removal of the remaining compounds from these industrial sites. Although contaminated soil around the source was excavated during the remedial action and the high concentrations of contaminants were reduced, typical groundwater contaminants such as petroleum hydrocarbons as gasoline (TPH-G), benzene, toluene, ethylbenzene, xylenes (BTEX), and oxygenates including methyl tert-butyl ether (MTBE), diisopropyl ether (DIPE), ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and tert-butyl alcohol (TBA) were persistently found at the studied sites around the source points. The plume and concentration of contaminants had changed their shapes and strength for all monitoring periods. Thus, additional source control seems to be a requirement for the complete removal of source contamination, which must be ascertained with groundwater and soil monitoring on a regular time base. For the study sites, monitored natural attenuation was relatively feasible for the long-term plan; however, it did not offer a perfect remediation solution for an ultimate goal because of residual toxic compounds that might have affected the surrounding residential areas at higher concentrations than their health limits. Therefore, as a remediation strategy, the combination of clean-up technology and natural attenuation with monitoring activities are more highly recommended than either clean-up or natural attenuation used separately.     

多溴联苯醚暴露的神经行为效应及其毒理机制

溴代阻燃剂多溴联苯醚(PBDEs)是一类在各类环境介质、生物体和人体中均能检出的普遍存在的环境污染物。我国的主要污染源之一集中于东南部地区的电子废弃物回收场地。由于PBDEs具有结构稳定性、亲脂性和生物累积性,电子废弃物拆解回收活动对当地生态系统和居民健康存在着巨大的潜在风险。PBDEs的发育神经毒性受到研究者的极大关注,但其神经行为毒性效应和机制仍需深入研究。行为学效应既是内在神经毒性机制的外在反映,也是推测环境污染物在高级别生物学水平(如种群、群落)影响的最有力试验手段。近年来,基于视频追踪系统技术的商业行为学分析设备迅速发展,使行为学效应测试在环境毒理学领域具备极大的潜力。本文结合近年来国内外环境毒理学研究进展,回顾了PBDEs的神经行为毒性效应,包括运动行为、掠食行为和认知行为,并分析了其可能的毒理机制,最后总结了当前研究存在的问题和未来研究需要关注的重点方向。     

Flammability limits of binary mixtures of dimethyl ether with five diluent gases

Flammability limits of binary mixtures of dimethyl ether with five kinds of diluent gases were measured by ASHRAE method at room temperature. The five diluent gases are nitrogen, carbon dioxide, chlorodifluoromethane (HCFC-22), 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea). The experimental results were correlated with the extended Le Chatelier's formula. It was found that the experimental results were well reproduced by the formula. In addition, flammability limits of binary mixtures of dimethyl ether with nitrogen and carbon dioxide were compared with the estimated values based on the adiabatic flame temperature method. The experimental results were found to be in satisfactory agreement with the estimated values.