碳键机制(CB-IV)模拟大气光化学反应的研究  

A Study on Using Carbon Bond Mechanism (CB-IV) to Model Atmospheric Photochemical Reaction

作　　者：余琦[1] 马蔚纯[1] 陈立民[1] 

机构地区：[1]复旦大学环境科学与工程系,上海200433

出　　处：《复旦学报（自然科学版）》2004年第4期633-639,共7页Journal of Fudan University：Natural Science

基　　金：国家自然科学基金资助项目(70103003)

摘　　要：通过单独求解碳键机制(CB IV),对污染条件下VOCs和NOx的初始浓度比和排放比分别变化情况下的O3浓度变化进行了模拟.结果表明,VOCs的增加使得上午时段O3浓度的增长速率提高,O3浓度峰值出现的时间提前;而且随着VOCs的增加,O3的浓度峰值开始会有所增加,但达到某一最大值后其峰值将会下降.VOCs对O3浓度变化的影响主要是二种作用的综合结果:随着VOCs的增加,VOCs反应生成的过氧氢自由基以及OLE和ETH等活泼组分对O3的消耗作用逐渐增强;VOCs的增加使得整个反应体系中HO2和XO2的浓度增加,造成了NO的消耗,从而削弱了NO对O3的消耗作用.夜间O3浓度的衰减主要受NOx,HO2,OLE和ETH等物质的影响.研究结果还表明,NO/NO2排放比例的变化对O3浓度的影响很小.The impact of the variation of VOCs to NO_x ratio of initial concentration and emission rate on ozone concentration predicted by Carbon Bond Mechanism IV(CB-IV) has been studied. The results showed that the increase of VOCs will accelerate the accumulation of ozone early in a day and bring the decrease of ozone concentration forward, and when the amount of VOCs increases from a small value to a fairly large value, the daily peak value of ozone concentration will increase at first, then decrease to some extent. The impact of changing the amount of VOCs on ozone concentration is the combination of the following two facts. One is that the consumption of ozone by OLE, ETH and the hydroperoxy radical produced by the VOCs reactions will increase as VOCs increases. The other is that the increase of VOCs will lead to the increase of the concentrations of the hydroperoxy radical and XO_2 (an operator of NO-to-NO_2 in CB-IV) which will reduce the concentration of nitrogen monoxide and thus the consumption of ozone by nitrogen monoxide. The temporal variation of ozone concentration at night is mainly controlled by the concentration of NO_x, HO_2, OLE, ETH. Results also showed that the ratio of nitrogen monoxide to nitrogen dioxide has little impact on ozone concentration.

关 键 词：碳键机制 挥发性有机物 氮氧化物 臭氧 光化学反应 大气 

分 类 号：X51[环境科学与工程—环境工程] P402[天文地球—大气物理学与大气环境]