【作者】 王明雨；

【导师】 张均东；

【作者基本信息】 大连海事大学 ， 轮机工程， 2014， 博士

【摘要】 本文对船舶柴油机的非常规排放的检测技术进行了较系统的研究。影响分析准确性的关键技术是非常规排放物的富集的方法和材料,本文以16种多环芳烃作为研究对象,通过液体捕获采样-低压吹扫富集-气质联用(ACC-LPPT-GC/MS)法解决了船舶柴油机排放的气态多环芳烃检测的核心技术,并建立了一套适合船舶柴油机排放的多环芳烃检测方法。使用液体捕获法代替传统的固体吸附法捕集气态多环芳烃,通过向溶液中添加不同性质的功能性添加剂,改变溶液的极性,产生协同效应,提高多环芳烃的溶解度。通过优化十六烷基三甲基溴化铵的浓度、添加无机盐解决乳化问题、筛选有机溶剂和采样温度,逐步提高液体法采集到的多环芳烃的回收率,最终均达到76%以上。为了解决柴油机排放的沸点高于250℃的多环芳烃富集效率低、回收率差的问题,对传统的吹扫捕集系统进行了改造,通过增加低压控制系统改变捕集系统的压力,建立了低压吹扫捕集系统。改造后的仪器与常压吹扫捕集系统进行比对,对高沸点的多环芳烃,如苯并[g,h,i]芘、苯并[a,h]葸和茚并[1,2,3-cd]芘的回收率大幅度提高,从低于22%到高于81%。在浓度范围0.02-50μg/L内16种多环芳烃的峰面积与浓度之间线性关系良好,相关系数范围在0.9981～0.9995之间；样品空白回收率为81.5-98.5%；多环芳烃的方法最低检出限在0.005-0.025μg/L的范围；定量限范围在0.002-0.050μg/L之间,检测限达到纳克级,实现了痕量分析。将新方法与传统方法进行了平行比对,传统方法检测到多环芳烃的总量为232.481μg/kWh,新方法检测到多环芳烃总量351.39μg,/kWh,新方法比传统的方法损失率减少33.83%。新方法从样品采集到多环芳烃检测少于30分钟,比传统方法节约90%的时间。该法解决传统的固体吸附材料吸附性能差、回收率低、损失率高耗时长等问题。新方法能快速、准确、可靠的实现痕量检测,简单易用,能有效的对非常规污染进行定性分析和定量检测,可做为非常规排放检测标准方法之一加以推广。结合已经建立的液体采样方法,通过改性纳米介质作为固相微萃取的吸附材料来富集样品中的多环芳烃。实验室自制TiO2纳米管阵列板,并探索阳离子表面活性剂CTAB作为修饰介质的条件,作为固相微萃取吸附材料。新材料对多环芳烃表现出良好的吸附和解吸附性能。16种多环芳烃的空白加标回收率范围在83.0-97.2%之间,日内精密度的相对标准偏差范围在3.7-9.1%之间。样品加标回收率在81～97%范围内,相对标准偏差范围在1.13-8.75%之间。针对传统富集方法采用的吸附材料存在吸附性能差、回收率低的问题,该方法简单有利推广应用。为了考查不同提取方式对颗粒物提取的效果,对几种常用的提取方法进行效果比较,最终采用索氏结合微波辅助提取法提取颗粒物中的多环芳烃及其衍生物。通过优化GC/MS方法进行分析测试,对颗粒物中硝基多环芳烃进行有效的预分离,并采用负离子化学电离源进行检测,检测限范围在0.001-0.040μg/L。颗粒吸附的16种多环芳烃的空白加标回收率范围在82.5～98.5%。结果重复性的相对标准偏差范围在0.239-8.786%,小于10%,说明方法的精确度较高。多环芳烃的样品加标回收率在78～98%范围内,硝基多环芳烃的样品加标回收率在79-95%,表明样品预处理过程未受到明显的污染。建立的方法可以应用于实际的柴油机颗粒物样品痕量分析。本文研究结果不但有利于进一步研究非常规排放的生成机理、排放规律、排放的毒理、优化柴油机的排放性能,而且可以使人们进一步认识到非常规排放的危害、促进非常规排放标准的制定和相关法规的制定,保护人类生存环境和健康。更多还原

【Abstract】 The dissertation focuses on systematically research of unregulated emissions produced by marine diesel engine.Enrichment materials and methods are key techniques that affected the accuracy of analysis. Sixteen EPA PAHs were selected as the object compounds. Aqueous-capture-collection (ACC),low-pressure-purge-and-trap (LPPT) and GC/MS were combined to solve the key problems in the detection of gaseous phase PAHs emitted from marine diesel engine, and invested a set of detection method. ACC method instead of the traditional solid adsorption method was used to trap gaseous PAHs.The functional additives of different properties were added into the solution, which could change the polarity of solution, synergistic effect, and increase the solubility of PAHs. The optimized concentration of hexadecyl trimethyl ammonium bromide (CTAB) was added firstly. Inorganic salt solution was added to eliminate emulsifications and organic solvent and sampling temperature was also tested to gradually improve the recovery of PAHs.Finally, recoveries achieved above76%. In order to solve the problem of low enrichment efficiency and poor recoveries of PAHs with boiling point higher than250℃, we modified a traditional purge-and-trap (P&T) system by introducing the pressure control system to form a LPPT system.Atmospheric pressure P&T and reformed LPPT system were compared. PAHs such as indeno[1,2,3,cd]pyrene, benzo[g,h,i]perylene and dibenz[a,h]anthracene rates improve significantly, from less than22%to more than81%.The linearity was good between peak area and concentration of PAHs at concentrations in the range of0.02-50)μg/L. The correlation coefficient of16PAHs was in the range of0.9981-0.9995.Blank recovery rates were in the range of81.5-98.5%.The PAHs limits of detection (LOD) were in the range of0.005-0.025μg/L. The limit of quantification (LOQ) was in the range of0.002-0.050μg/L. The LOD reached to nanogram grade, which realized trace analysis.The parallel comparison of the new method and the traditional method showed that the traditional method detected the total PAHs was232.481μg/kWh, and the result of new method was351.39μg/kWh. The new method was33.83%less than the loss rate of traditional method. The novel method for determination of PAHs costed less than30minutes from the samples collection to analysis, which saved90%time than the traditional method. The method solved the problems such as poor adsorption performance, low recovery rate, high loss rate and time consuming. The new method can realize fast, accurate, reliable and trace detection, which can effectively make the qualitative analysis and the quantitative detection of unconventional emissions. It can be promoted as one of standard methods for detection of unconventional emissions.Combining the established ACC method, nanomedium was modifed as the solid phase microextraction (μSPE) adsorption material. TiO2nanotube array was made in labortory, and modification conditions of cationic surfactant CTAB was explored as μSPE absorption material. New materials showed good performance in adsorption and desorption. Blank recoveries of16PAHs were ranged from83%to97.2%.The relative standard deviations (RSD) of the intra-day precision were ranged from3.7%to9.1%. The recovery rates were in the range of81-97%, and the RSD were in the range of1.13-8.75%. As the traditional enrichment methods have the problems such as low adsorption performance and low recovery rate, the method was simple and favorable popularization and application. In order to examine effects of different methods for extraction of particle matters (PM), several extraction methods were compared. Finally Soxhlet combining microwave extraction method was adopted for extraction of PAHs their derivatives. Through optimization of GC/MS method, effectively preseparation of nitro-PAHs in PM was used. Negative ion chemical ionization source was used for detection, and the LOD in the range of0.001-0.040μg/L. PAHs adsorbed in blank recoveries were in the range of82.5-98.5%. Repeatability RSD was in the range of0.239-8.786%. It was less than10%that illustrated high precision. Sample recovery rates of PAHs were in the range of78-98%and recoveries of nitro-PAHs in the range of79-95%that indicated the sample pretreatment process was not obvious polluted. The method can be applied to trace analysis of diesel PM. The results of this study not only useful for the research of generation mechanism, emission performance, emission toxicology and optimization of emissions properties, but also can recognize the dangers of unconventional emissions, and promote the formulation of the unconventional emission standards and related regulations, so as to protect environment for human survival and health.更多还原