珠江三角洲地区臭氧及其前体物非线性响应特征及控制对策研究

发布时间：2019-03-30 20:47

【摘要】：近年来,随着城市化、工业化的快速发展以高浓度臭氧(O3)为特征的光化学烟雾污染在珠江三角洲地区(以下简称珠三角)时有发生,臭氧成为该地区首要污染物的频率越来越高。由于臭氧与其前体物挥发性有机物(VOCs)和氮氧化物(NOx)呈显著的非线性响应关系,且受气象条件、排放源分布和土地利用类型等影响,臭氧污染仍然是珠三角地区大气污染控制研究的重点和难点之一。本研究在本地化模型物种谱建立与对比的基础上,利用经验动力学方法(Empirical Kinetics Modeling Approach,EKMA)建立了珠三角典型地区臭氧及其前体物的非线性响应关系。通过分析臭氧及其前体物关系特征,识别各典型地区臭氧生成机制并评估不同前体物削减比例对臭氧控制效果影响,为该区域臭氧控制政策的制定提供科学性建议。本论文的主要工作和结论如下:首先,在道路移动源、工业有机溶剂使用和非工业有机溶剂使用源等典型VOCs化学成分谱实测研究的基础上,建立了基于大气模型化学机理CB05和SAPRC-07的本地化模型物种谱,并与基于USEPA SPECIATE数据库建立的物种谱进行对比分析。结果显示:(1)基于SAPRC-07机制建立的本地物种谱与SPECIATE差异较CB05机制明显;(2)制鞋、家具制造、轻型汽油车和摩托车等本地物种谱与SPECIATE物种化结果差异较小;(3)印制电路板、轻型柴油车、LPG出租车及非工业有机溶剂使用源的物种谱差异较为明显。再者,通过对比验证本地与SPECIATE模型物种谱对该区域臭氧模拟效果影响,建立适用于该地区臭氧特征综合分析的模拟平台。结果表明:基于CB05机制的臭氧模拟结果与监测值吻合度更高;利用本地模型物种谱的模拟平台更有利于该地区臭氧高浓度的捕捉。在此基础上,基于珠三角地区污染物浓度监测值和城市特点、土地利用类型分布、监测站点属性以及前体物削减比例研究等,建立了典型区域在臭氧日及非臭氧日的臭氧等浓度曲线,探讨不同污染时段各典型区域臭氧及其前体物非线性响应关系。结果表明:对于典型臭氧污染时段,(1)以广州和深圳市区为代表的典型市区和以东莞、佛山工业区为代表的典型工业区夏季臭氧受NOx和VOCs共同影响,秋季臭氧则主要受VOC控制;(2)以万顷沙为代表的典型城郊区夏季和秋季臭氧均处于VOC控制区;(3)以江门西南部为代表的典型乡村夏季臭氧生成机制为明显的NOx控制,秋季臭氧处于过渡区,NOx作用较VOCs显著。最后,基于各区域典型污染时段臭氧等浓度曲线,分析了典型的前体物削减比例对臭氧控制效果影响。结果表明:由于臭氧生成机制具有区域性和季节性特征,最佳的前体物削减比例不可一概而论。在本研究中,从理论上讲,对于大部分典型区域而言,VOCs/NOx=1:2和VOCs/NOx=3:1分别为夏季和秋季臭氧较佳前体物削减比例。但综合控制方案的效果及可行性,VOCs/NOx=1:1可能更适用于珠三角地区高浓度臭氧污染的控制。
[Abstract]:In recent years, with the urbanization, the rapid development of industrialization characterized by high concentration of ozone (O3) photochemical smog pollution in the Pearl River Delta region (hereinafter referred to as the Pearl River Delta) from time to time. Ozone is becoming the primary pollutant in the region more and more frequently. Ozone has a significant nonlinear response to volatile organic compounds (VOCs) and nitrogen oxides (NOx), and is affected by meteorological conditions, distribution of emission sources and land use types. Ozone pollution is still one of the key and difficult points in the study of air pollution control in Pearl River Delta. Based on the establishment and comparison of localized model species spectra, the nonlinear response relationship of ozone and its precursors in typical Pearl River Delta region was established by using empirical dynamics method (Empirical Kinetics Modeling Approach,EKMA. Based on the analysis of the relationship between ozone and its precursors, the mechanism of ozone generation in typical areas was identified and the effect of different reduction ratios of precursors on ozone control was evaluated, which provided scientific suggestions for the formulation of ozone control policy in this region. The main work and conclusions of this paper are as follows: firstly, based on the measurement of typical VOCs chemical components, such as road moving source, industrial organic solvent use and non-industrial organic solvent usage source, the main results of this paper are as follows: A localized model species spectrum based on atmospheric model chemistry mechanism CB05 and SAPRC-07 was established and compared with the species spectrum based on USEPA SPECIATE database. The results showed that: (1) the difference of local species spectrum based on SAPRC-07 mechanism and SPECIATE mechanism was more obvious than that of CB05 mechanism, (2) the difference of local species spectrum such as shoe making, furniture manufacture, light gasoline truck and motorcycle was less than that of SPECIATE. (3) the species profiles of printed circuit boards, light diesel vehicles, LPG taxis and non-industrial organic solvents were significantly different. Furthermore, the effects of local and SPECIATE model species spectra on ozone simulation in this region are verified and a simulation platform suitable for comprehensive analysis of ozone characteristics in this region is established. The results show that the ozone simulation results based on the CB05 mechanism have a higher degree of coincidence with the monitoring values, and the simulation platform based on the local model species profile is more conducive to the capture of ozone concentration in this area. On this basis, based on the pollutant concentration monitoring values and urban characteristics in the Pearl River Delta region, the distribution of land use types, the attributes of monitoring stations and the reduction ratio of precursors, and so on, The isoconcentration curves of ozone in typical regions on ozone day and non-ozone day were established, and the nonlinear responses of ozone and its precursors in different pollution periods were discussed. The results show that: (1) for the typical ozone pollution period, (1) the typical urban areas represented by Guangzhou and Shenzhen, and the typical industrial zones represented by Dongguan and Foshan industrial zones are affected by NOx and VOCs in summer. In autumn, ozone was mainly controlled by VOC. (2) the ozone in summer and autumn of typical suburban areas, represented by sand of 10,000 hectares, is in the VOC-controlled area; (3) the typical rural ozone generation mechanism represented by south-west of Jiangmen was obviously controlled by NOx in summer. In autumn, ozone was in the transition zone, and the effect of NOx was more significant than that of VOCs. Finally, based on the ozone isoconcentration curve during typical pollution period in each region, the influence of typical precursor reduction ratio on ozone control effect was analyzed. The results show that due to the regional and seasonal characteristics of ozone generation mechanism, the optimal ratio of precursor reduction cannot be generalized. In this study, in theory, for most typical regions, VOCs/NOx=1:2 and VOCs/NOx=3:1 are the better proportion of ozone reduction in summer and autumn, respectively. However, the effect and feasibility of the integrated control scheme, VOCs/NOx=1:1 may be more suitable for the control of high concentration ozone pollution in Pearl River Delta area.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X515

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