摘要
利用自制光化学烟雾箱模拟了丙烷和NOx大气光化学反应,研究了相对湿度以及丙烷与NOx初始浓度比值对臭氧生成的影响.实验表明,臭氧最大值及丙烷的臭氧生成活性最大值(IRmax)都随相对湿度的增大而减小.低相对湿度时,臭氧最大值大约出现在反应的22 h,IRmax变化范围为0.023 1～0.039 1;而高相对湿度时,臭氧最大值大约出现在反应的16 h,IRmax变化范围为0.017 2～0.032 0.在反应的20 h内,前12 h内相对湿度对丙酮的生成量影响不大,12 h后低相对湿度时丙酮生成量更大.在实验的4～20 h内,相对湿度为17%时,丙酮浓度为153×10-9～364×10-9;而相对湿度为62%时,丙酮浓度为167×10-9～302×10-9.臭氧最大值随着丙烷与NOx初始浓度比值增加而减少,在低相对湿度时线性负相关性更好.另外,还利用了MCM丙烷子机制对反应进行了数值模拟,并与实验结果进行比较,发现两者还存在较大的偏差.
Atmospheric photochemical reactions of propane and NOx were simulated with a self-made smog chamber.The effects of relative humidity（RH） and 0/0 ratio on ozone formation were studied.The results showed that both the maximum ozone concentration and the maximum value of incremental reactivity（IRmax） of propane decreased linearly with increasing RH.Under lower RH conditions,the occurrence time of peak ozone concentration was about 22 h after the beginning of reaction,and IRmax varied from 0.023 1 to 0.039 1,while under higher RH conditions the occurrence time of peak ozone concentration was 16 h,and IRmax ranged from 0.017 2 to 0.032 0.During the 20 h of reaction,within the first 12 h RH did not significantly affect the yield of acetone,whereas after 12 h the lower RH condition could lead to relatively greater amount of acetone.During the first 4-20 h of experiments,acetone concentrations ranged from 153×10-9 to 364×10-9 at 17% RH and from 167×10-9 to 302×10-9 at 62% RH,respectively.Maximum ozone concentrations decreased with increasing 0/0 ratio and a better negative linear relationship between them was obtained under the lower RH conditions.The smog chamber data and the results from simulation of the C3H8-NOx reactions using the sub-mechanism of MCM were compared,and a significant deviation was found between these two results.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2012年第8期2551-2557,共7页
Environmental Science
基金
中国科学院知识创新工程项目(KZCX2-YW-Q02-03)
关键词
烟雾箱
丙烷
光化学反应
相对湿度
臭氧
丙酮
smog, chamber： oronane： nhotochemical reaction： relative humidity： ozone： acetone
