光腔衰荡光谱方法探测大气中氮氧化物

发布时间：2018-05-02 15:11

本文选题：光腔衰荡光谱 + 二氧化氮　；参考：《中国科学技术大学》2017年博士论文

【摘要】：氮氧化物 NO_y,包括 NO_x(NO+NO_2),NO_3,HONO,HNO_3,N2O5,PNs(total peroxy nitrates, RO_2NO_2),ANs (total alkyl nitrates, RONO_2),和 aerosol nitrates等,作为大气中重要的污染物,对于O_3、OH和HO_2等自由基含量、光化学烟雾以及二次有机气溶胶的形成具有重要的影响。因此,实现氮氧化物的准确快速监测以及排放监管,是目前环境科学和大气化学重点关注的课题之一。本论文主要工作为发展光腔衰荡光谱(CRDS)方法探测大气中NO、NO_2、RNO_2(PNs+ANs)、NO_3。第一章主要介绍了相关大气化学的研究背景,NO、NO_2、RNO_2、NO_3参与的大气化学过程。简单分析了这些物质在大气中如何影响大气组分,改变空气质量的机制。还介绍了 NO_2的主要测量技术,并分析了各自优势以及局限性。最后,重点介绍了光腔衰荡光谱技术的发展历程及其测量原理。第二章介绍了基于405 nm半导体激光的双腔光腔衰荡光谱系统用于探测NO_2、RNO_2和NO,包括系统的结构、标定与检验。其NO_2的探测灵敏度度可以达到 0.09 ppbv(1 s)。第三章介绍了基于662 nm半导体激光的NO_3光腔衰荡光谱系统。其NO_3探测灵敏度达到了 1 pptv(1 s)。第四章中,我们利用405 nm双腔光腔衰荡光谱系统实现了 NO_2、RNO_2的监测,分析了监测过程中两次雾霾事件的可能原因,阐述了 NO_2、RNO_2对二次有机气溶胶的产生的影响。我们利用405 nm双腔光腔衰荡光谱系统,与商用的钼催化NO_x分析仪对比监测大气中了大气中的NO_2;评定了钼催化NO_x分析仪测定大气中NO_2的偏差大小以及来源。此外,我们分别利用405 nm和662 nm光腔衰荡光谱系统实现了对大气中NO和NO_3的连续监测。第五章对现有实验的进行了总结,并对未来后续的拓展研究做了分析。
[Abstract]:As important pollutants in the atmosphere, no _ y, including NO_x(NO no _ 2 / no _ 3, HNOS _ 3N _ 2O _ 5 / PNs total peroxy nitrates, RO2NO _ 2 / ANs total alkyl nitrates, etc., have important effects on the free radical contents such as O3OH and HO_2, photochemical smog and the formation of secondary organic aerosols. Therefore, accurate and rapid monitoring of nitrogen oxides and emission regulation is one of the most important issues in environmental science and atmospheric chemistry. The main work of this thesis is to develop the optical cavity ring-down spectroscopy (CRDSs) method for the detection of NONNO2 / RNO2 / PNNs and NO3 in the atmosphere. In the first chapter, the background of atmospheric chemistry is introduced. The mechanism of how these substances affect atmospheric components and change air quality in the atmosphere is briefly analyzed. The main measurement techniques of NO_2 are also introduced, and their advantages and limitations are analyzed. Finally, the development history and measurement principle of cavity ring-down spectroscopy are introduced. In chapter 2, a double-cavity cavity ring-down spectroscopy system based on 405nm semiconductor laser is introduced to detect NO2 / RNO2 and NO2, including the structure, calibration and verification of the system. The detection sensitivity of NO_2 can reach 0.09 ppbv(1 / s. In chapter 3, the NO_3 cavity ring-down spectrum system based on 662nm semiconductor laser is introduced. The sensitivity of NO_3 detection is up to 1 pptv(1 sm. In chapter 4, we use 405nm double-cavity ring-down spectrum system to realize the monitoring of no _ 2O _ 2 / RNO2. The possible causes of two haze events in the monitoring process are analyzed, and the influence of no _ 2O _ 2 RNO2 on the production of secondary organic aerosol is discussed. Using 405nm double-cavity ring-down spectrum system, compared with the commercial molybdenum catalytic NO_x analyzer, the NO2 in the atmosphere was monitored, and the deviation and source of the NO_2 in the atmosphere were evaluated by using the molybdenum catalytic NO_x analyzer. In addition, we have realized the continuous monitoring of no and NO_3 in the atmosphere by using 405nm and 662nm optical cavity ring-down spectroscopy system, respectively. The fifth chapter summarizes the existing experiments and analyzes the future development research.
【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O657.3;X831

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