速生桉叶片BVOCs释放特性研究
发布时间：2018-09-03 11:22
【摘要】：植物会排放大量的VOCs,广西地处低纬度地区,紫外线较强,加之大气中的氮氧化物随汽车保有量增加逐年递增,为臭氧等二次污染物形成提供了条件。在白天BVOCs易与臭氧接触反应形成SOA。这些复杂的反应产物与大气颗粒物、光化学烟雾等环境问题有潜在的联系。为满足造纸业需求,华南地区大面积种植速生桉树,其中广西种植桉树面积最大。研究报道,桉树是BVOCs释放量最多的树种之一。然而,最近的研究鲜有大面积速生桉树释放BVOCs的田野调查报道。本文主要以尾叶桉为研究对象,系统地调查研究了尾叶桉叶片在离体及活体条件下BVOCs释放特性及主要化学成分,并对速生桉树叶片释放的BVOCs对环境的潜在影响进行初步评估,研究结果如下：(1)尾叶桉叶片释放的BVOCs化学成分主要有异戊二烯、D-柠檬烯、α-蒎烯、桉树脑、叶醇、青叶醛等12种化学物质,其中异戊二烯与BVOCs释放速率呈二次函数关系,表达式为EBVOCs=0.31Eisoprene2+0.37Eisoprene。富集法和动态枝法对BVOCs调查,其释放速率没有明显的差异；(2)尾叶桉活体叶片BVOCs释放速率呈现出明显的日变化和季节变化特性。在一天内,中午(12：00～14：00)释放速率达峰值为15.03±3.91 μgg-1h-1,早上和傍晚时段释放速率分别为3.37μgg-1h-1和4.40μgg-1h-1,日落后未检测出。季节性释放速率变化表现为单峰变化特性,峰值释放速率在8月份达到为23.37±5.53μgg-1h-1。由于存在光合抑制和高温胁迫作用,BVOCs释放速率并不随光强单调递增,在光强超过40000 lux后释放速率开始减少；(3)与活体叶片相似,离体叶片释放BVOCs同样受到光照的影响,在20000～30000 lux和0～5000 lux范围内光强变化释放量增量微弱。叶龄、机械损伤和离体时间影响BVOCs释放量明显,成熟叶片释放量达到最大随后衰减,机械损伤越严重释放量越少,随离体时间增加释放量减少；(4)不同树种BVOCs释放速率存在明显差异,其中活体叶片BVOCs释放速率最高的是窿缘桉,达到12.32±2.04 μgg-1h-1。相对于桉树品种,小叶榕活体叶片BVOCs释放速率均低于桉树。(5)以8年生尾叶桉树林为标准,在夏季,广西区内异戊二烯峰值释放量高达43 t,白天释放量高达170 t,其中中午时段释放的异戊二烯形成SOA的量为125 Kg。
[Abstract]:A large amount of VOCs, emissions from plants in Guangxi are located in low latitudes, and the ultraviolet radiation is strong. In addition, the nitrogen oxides in the atmosphere increase year by year with the increase of automobile content, which provides the conditions for the formation of secondary pollutants such as ozone. During daytime, BVOCs can easily react with ozone to form SOA.. These complex reaction products are potentially associated with environmental problems such as atmospheric particulates and photochemical smog. In order to meet the demand of paper industry, a large area of fast growing eucalyptus was planted in South China, of which Guangxi was the largest. It is reported that eucalyptus is one of the most released species of BVOCs. However, recent studies have rarely reported the release of BVOCs from large areas of fast growing eucalyptus. In this paper, the characteristics and chemical constituents of BVOCs release from eucalyptus urophylla leaves in vitro and in vivo were investigated systematically, and the potential environmental effects of BVOCs released from leaves of fast-growing eucalyptus were preliminarily evaluated. The results are as follows: (1) the BVOCs released from the leaves of eucalyptus caudate mainly contains 12 chemical substances, such as isoprene D-limonene, 伪 -pinene, eucalyptus brain, leaf alcohol, cyanide and so on, in which isoprene has a quadratic function relationship with the release rate of BVOCs. The expression is EBVOCs=0.31Eisoprene2 0.37 Eisoprene. There was no significant difference in the release rate of BVOCs between the enrichment method and the dynamic branch method. (2) the BVOCs release rate of living leaves of Eucalyptus urophylla showed obvious diurnal and seasonal variation characteristics. Within one day, the release rate reached a peak of 15.03 卤3.91 渭 gg-1h-1, at noon (12: 00 14: 00) and was not detected after sunset at 3.37 渭 gg-1h-1 in the morning and 4.40 渭 gg-1h-1, in the evening, respectively. The seasonal release rate varied with a single peak, and the peak release rate reached 23.37 卤5.53 渭 gg-1h-1. in August. The release rate of BVOCs did not increase monotonously with light intensity due to the existence of photosynthetic inhibition and high temperature stress, and began to decrease after light intensity exceeded 40000 lux. (3) the release of BVOCs from isolated leaves was also affected by light exposure similar to that of living leaves. In the range of 30000 lux and 05000 lux, the increment of light intensity is weak. Leaf age, mechanical injury and time in vitro significantly affected the release of BVOCs, and the release of mature leaf reached the maximum and then decreased. The more serious the mechanical damage, the less the release was, and the less the release was with the increase of the time in vitro. (4) there were significant differences in BVOCs release rate among different tree species, and the highest BVOCs release rate in living leaves was Eucalyptus fornix (12.32 卤2.04 渭 gg-1h-1.). Compared with eucalyptus varieties, the rate of BVOCs release from living leaves of Ficus microphylla was lower than that of eucalyptus. (5) in summer, the rate of BVOCs release was lower than that of eucalyptus. The peak release of isoprene in Guangxi was 43 t and the daytime release was 170t. The amount of isoprene released at noon to form SOA was 125 Kg..
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X173
本文编号：2219836
[Abstract]:A large amount of VOCs, emissions from plants in Guangxi are located in low latitudes, and the ultraviolet radiation is strong. In addition, the nitrogen oxides in the atmosphere increase year by year with the increase of automobile content, which provides the conditions for the formation of secondary pollutants such as ozone. During daytime, BVOCs can easily react with ozone to form SOA.. These complex reaction products are potentially associated with environmental problems such as atmospheric particulates and photochemical smog. In order to meet the demand of paper industry, a large area of fast growing eucalyptus was planted in South China, of which Guangxi was the largest. It is reported that eucalyptus is one of the most released species of BVOCs. However, recent studies have rarely reported the release of BVOCs from large areas of fast growing eucalyptus. In this paper, the characteristics and chemical constituents of BVOCs release from eucalyptus urophylla leaves in vitro and in vivo were investigated systematically, and the potential environmental effects of BVOCs released from leaves of fast-growing eucalyptus were preliminarily evaluated. The results are as follows: (1) the BVOCs released from the leaves of eucalyptus caudate mainly contains 12 chemical substances, such as isoprene D-limonene, 伪 -pinene, eucalyptus brain, leaf alcohol, cyanide and so on, in which isoprene has a quadratic function relationship with the release rate of BVOCs. The expression is EBVOCs=0.31Eisoprene2 0.37 Eisoprene. There was no significant difference in the release rate of BVOCs between the enrichment method and the dynamic branch method. (2) the BVOCs release rate of living leaves of Eucalyptus urophylla showed obvious diurnal and seasonal variation characteristics. Within one day, the release rate reached a peak of 15.03 卤3.91 渭 gg-1h-1, at noon (12: 00 14: 00) and was not detected after sunset at 3.37 渭 gg-1h-1 in the morning and 4.40 渭 gg-1h-1, in the evening, respectively. The seasonal release rate varied with a single peak, and the peak release rate reached 23.37 卤5.53 渭 gg-1h-1. in August. The release rate of BVOCs did not increase monotonously with light intensity due to the existence of photosynthetic inhibition and high temperature stress, and began to decrease after light intensity exceeded 40000 lux. (3) the release of BVOCs from isolated leaves was also affected by light exposure similar to that of living leaves. In the range of 30000 lux and 05000 lux, the increment of light intensity is weak. Leaf age, mechanical injury and time in vitro significantly affected the release of BVOCs, and the release of mature leaf reached the maximum and then decreased. The more serious the mechanical damage, the less the release was, and the less the release was with the increase of the time in vitro. (4) there were significant differences in BVOCs release rate among different tree species, and the highest BVOCs release rate in living leaves was Eucalyptus fornix (12.32 卤2.04 渭 gg-1h-1.). Compared with eucalyptus varieties, the rate of BVOCs release from living leaves of Ficus microphylla was lower than that of eucalyptus. (5) in summer, the rate of BVOCs release was lower than that of eucalyptus. The peak release of isoprene in Guangxi was 43 t and the daytime release was 170t. The amount of isoprene released at noon to form SOA was 125 Kg..
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X173
【引证文献】
相关会议论文 前1条
1 唐利利;;南宁市区大气臭氧浓度变化规律及污染水平研究[A];2010中国环境科学学会学术年会论文集(第一卷)[C];2010年
，本文编号：2219836
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