| 题名 | 大气羰基硫来源的检测技术及其应用 |
| 作者 | 杜倩倩 |
| 学位类别 | 硕士 |
| 答辩日期 | 2016-11 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 牟玉静 |
| 关键词 | water, photochemical, domestic coal combustion, COS, emission factor 湖水，光化学，居民燃煤，羰基硫，排放因子 |
| 其他题名 | Study on detection technology for carbonyl sulfide and its application |
| 学位专业 | 环境工程 |
| 中文摘要 | 羰基硫(COS)是大气中含硫量最丰富的一种还原性的含硫化合物，对全球太阳辐射和平流层的臭氧具有重要的影响。然而，目前人们对其源和汇的认识还存在着很大的不确定性，且存在显著缺失来源。本论文以湖水和居民燃煤为研究对象，较系统地研究了湖水光化学 COS产生机制及居民燃煤 COS的排放因子，为认识大气中COS的来源提供了新的科学数据，主要取得了以下研究成果： 基于带有火焰光度检测器的气相色谱(GC-FPD)，开发了水样中 COS等初始浓度及光化学产生的检测技术，并研究了北京市奥林匹克森林公园奥海湖水中COS、二硫化碳(CS2)和二甲基硫(DMS)的初始浓度及其光化学形成潜势。发现湖水中COS、CS2和DMS均是过饱和的，其初始溶解浓度分别为0.91±0.073 nmolL-1、0.55±0.071 nmol L-1和0.37±0.062 nmol L-1。湖水在 302 nm和365 nm光辐射下可明显产生 COS和CS2，推测湖水中过饱和的 COS和 CS2可能来自于其前体物的光化学转化。湖水在 253.7 nm光辐射下，COS、CS2和DMS浓度变化趋势相似，且氧气对它们的产生具有明显抑制作用，表明 COS、CS2和DMS可能来自相同的光化学前体物。此外，研究还发现：1)湖水中引入甲醛可明显抑制COS的产生，但显著促进 CS2的产生；2)引入丙酮可明显抑制 COS的产生，并明显促进 DMS的产生；3)引入含硫氨基酸可同时促进COS和CS2的产生；4)同时引入丙酮和氨基酸，COS和DMS的变化趋势与湖水单独引入丙酮完全一致。基于以上研究结果，推测了水体中，COS、CS2和 DMS的光化学产生机制。 基于居民燃煤测试平台，研究了居民燃煤 COS、一氧化碳(CO)和二氧化硫(SO2)的排放特征，发现 COS和 CO的排放主要集中在加煤后火焰熄灭的过程，而SO2的排放主要集中在有火焰燃烧过程。获得了居民燃煤实际燃烧工况下COS的排放因子(0.57±0.10 g COS kg-1)，该因子比目前基于燃煤发电厂估算全球燃煤 COS排放的因子高约50倍。如果本研究所获得的 COS排放因子适用于世界范围的家用煤炉和工业煤炉，全球煤炭燃烧 COS的排放可高达 612 Gg S yr-1，几乎可弥补目前大气中 COS的缺失来源(约 800 Gg S yr-1)。 |
| 英文摘要 | Carbonyl sulfide (COS) is the most abundant reduced sulfur trace gas in the atmosphere and has important impacts on the global sunlight irradiation and stratospheric ozone. Based on the studies about COS, the understanding of the sources and sinks of COS contains considerable uncertainties, and large missing sources are existed in the global COS budget. Therefore, in this dissertation, the photochemical formation mechanisms of carbonyl sulfide in lake water and COS emission factors for domestic coal combustion were intensively studied. Based on the technology of gas chromatograph equipped with a flame photometric detector (GC-FPD), the detecting technology of dissolved and photochemical formed COS, et al, were developed. The initial dissolved concentrations and photochemical formation mechanisms of COS, carbon disulfide (CS2) and dimethyl sulfide (DMS) were intensively studied with the water from the Aohai Lake of Beijing city in this study. The lake water was found to be highly supersaturated for COS, CS2 and DMS,with their initial concentrations of 0.91±0.073 nmol L-1, 0.55±0.071 nmol L-1 and 0.37±0.062 nmol L-1, respectively. The remarkable photochemical production of COS and CS2 in the lake water under irradiation of 365 nm and 302 nm implied that their supersaturation was probably ascribed to the photochemical formation from their precursors. Under 253.7 nm irraidation, the similar variation trends of COS, CS2 and DMS with irradiation time and inhibiting effects of oxygen on COS, CS2 and DMS formaion indicated that they might be from the same precursors. Besides, it had been found in this study that (a) adding formaldehyde in lake water was effectively favor of CS2 production but inhibited COS formation; (b) adding acetone in lake water was effectively favor of DMS production but inhibited COS formation; (c) adding amino acids in lake water was pormated COS and CS2 formation; (d) the variation trends of COS and DMS in lake water added with acetone and amino acids were almost same as the original lake water with addition of aceton. Based on the results above, the photochemical formation mechanisms for COS, CS2 and DMS in water were derived in this study. Based on the domestic stove combustion platform, the emission characteristics of COS, carbon monoxide (CO) and sulfur dioxide (SO2) were investigated in this study.The emissions of COS and CO mainly occurred under the state of flame extinguishment after coal loading, whereas the emission of SO2 was mainly from combustion with flame. The emission factor of COS from the domestic coal stove was 0.57±0.10 g COS kg-1, about a factor of 50 greater than that from the coal power plant which is currently used for estimating global COS emission from coal combustion. If COS emission factor from the domestic stove measured in this study was applied to worldwide domestic stoves and industrial boilers, the global COS emission from coal combustion would be 612 Gg S yr-1 which almost makes up the current shortfall of 800 Gg S yr-1 in COS sources. |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/36789]  |
| 专题 | 生态环境研究中心_大气环境科学实验室 |
| 推荐引用方式 GB/T 7714 | 杜倩倩. 大气羰基硫来源的检测技术及其应用[D]. 北京. 中国科学院研究生院. 2016. |
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