da Silva Cleyton Martins, Corrêa Sergio Machado, Arbilla Graciela
Instituto de Química, Centro de Tecnologia, Universidade Federal do Rio de Janeiro, Bloco A, Sala 402A, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil.
Universidade Veiga de Almeida, Campus Maracanã, Tijuca, Rio de Janeiro, RJ, Brazil.
Bull Environ Contam Toxicol. 2018 Jan;100(1):184-188. doi: 10.1007/s00128-017-2248-6. Epub 2017 Dec 13.
The potential role of isoprene oxidative processes, as well as the possible impact of air pollution on isoprene emissions, are more important in tropical cities, surrounded by rainforests. In this study, the contribution of isoprene to ozone formation was determined considering different scenarios, mainly volatile organic compounds/NO (VOC/NO ) ratios, and typical atmospheric conditions for the city of Rio de Janeiro, where more than 36% of the urbanized area is covered by vegetation. Ozone isopleths and incremental reactivity coefficients (IR) were evaluated to understand the direct contribution of isoprene to ground-level ozone formation and the negative impact of anthropogenic NO emissions on the natural atmospheric balance. Although isoprene accounted for only 2.7% of the total VOC mass, excluding the isoprene concentration from the model reduced the maximum ozone value by 14.1%. The calculated IR coefficient (grams of O formed per gram of added isoprene) was 2.2 for a VOC/NO ratio of 8.86.
异戊二烯氧化过程的潜在作用，以及空气污染对异戊二烯排放可能产生的影响，在被雨林环绕的热带城市中更为重要。在本研究中，考虑到不同情景，主要是挥发性有机化合物/一氧化氮（VOC/NO）比率，以及里约热内卢市的典型大气条件，确定了异戊二烯对臭氧形成的贡献。里约热内卢市超过36%的城市化区域被植被覆盖。评估了臭氧等值线和增量反应系数（IR），以了解异戊二烯对地面臭氧形成的直接贡献以及人为一氧化氮排放对自然大气平衡的负面影响。尽管异戊二烯仅占VOC总量的2.7%，但从模型中排除异戊二烯浓度后，最大臭氧值降低了14.1%。对于VOC/NO比率为8.86的情况，计算出的IR系数（每添加一克异戊二烯形成的臭氧克数）为2.2。
