Modeling the impact of chlorine emissions from coal combustion and prescribed waste incineration on tropospheric ozone formation in China
Modeling the impact of chlorine emissions from coal combustion and prescribed waste incineration on tropospheric ozone formation in China
复制标题
模拟燃煤和规定的废物焚烧产生的氯排放对中国对流层臭氧形成的影响
DOI：
10.5194/acp-18-2709-2018
复制
发表时间：
2018-02-26
影响因子：
6.3
通讯作者：
Wei, Xiaolin
中科院分区：
文献类型：
--
作者：
Liu, Yiming;Fan, Qi;Wei, Xiaolin
氯自由基可以增强大气氧化，从而潜在地增加对流层臭氧浓度。然而，由于缺乏足够分辨率的空气质量模型中使用的氯排放清单，量化氯排放对中国臭氧形成的影响的研究很少。在这项研究中，首次开发了中国(ACEIC)的人为氯排放清单，包括燃煤和指定垃圾焚烧(垃圾焚烧厂)的氯化氢(HCl)和分子氯(Cl2-2)的排放。2012年，中国燃煤产生的氯化氢和氯离子排放量估计分别为232.9和9.4千克，而焚烧规定垃圾的氯化氢排放量估计为2.9千克。在空间上，中国平原北部、长江三角洲和四川盆地的HCl和Cl2-排放量最高。使用社区多尺度空气质量(CMAQ)模拟系统对2011年11月的空气质量模型进行了模拟，并对有无氯排放的模拟结果进行了比较。当模型考虑人为氯排放时，模拟的HCl、Cl2-和ClNO2的大小与观测结果吻合较好。ACEIC的加入增加了细颗粒Cl-的浓度，促进了Cl2-与N2O5的非均相反应，导致ClNO2的生成量增加。上午ClNO2和Cl2-的光解和下午HCl与OH的反应产生氯自由基，从而加速对流层的氧化。考虑人为氯排放后，中国的细颗粒物氯、1hClNO2和氯自由基的月平均浓度分别增加了约2.0mgm(-3)、773PPTV和1.5×10(3)分子cm(-3)。同时，月平均日最高8hO-3浓度增加了2.0ppbv(4.1%)，而NOx月平均浓度下降了0.5ppbv(6.1%)。人为的氯排放可能会使中国的1hO-3浓度增加7.7ppbv。这项研究强调了将人为氯排放纳入空气质量模拟的必要性，并证明了其在对流层臭氧形成中的重要性。
Chlorine radicals can enhance atmospheric oxidation, which potentially increases tropospheric ozone concentration. However, few studies have been done to quantify the impact of chlorine emissions on ozone formation in China due to the lack of a chlorine emission inventory used in air quality models with sufficient resolution. In this study, the Anthropogenic Chlorine Emissions Inventory for China (ACEIC) was developed for the first time, including emissions of hydrogen chloride (HCl) and molecular chlorine (Cl-2) from coal combustion and prescribed waste incineration (waste incineration plant). The HCl and Cl-2 emissions from coal combustion in China in 2012 were estimated to be 232.9 and 9.4 Gg, respectively, while HCl emission from prescribed waste incineration was estimated to be 2.9 Gg. Spatially the highest emissions of HCl and Cl-2 were found in the North China Plain, the Yangtze River Delta, and the Sichuan Basin. Air quality model simulations with the Community Multiscale Air Quality (CMAQ) modeling system were performed for November 2011, and the modeling results derived with and without chlorine emissions were compared. The magnitude of the simulated HCl, Cl-2 and ClNO2 agreed reasonably with the observation when anthropogenic chlorine emissions were included in the model. The inclusion of the ACEIC increased the concentration of fine particulate Cl-, leading to enhanced heterogeneous reactions between Cl- and N2O5, which resulted in the higher production of ClNO2. Photolysis of ClNO2 and Cl-2 in the morning and the reaction of HCl with OH in the afternoon produced chlorine radicals which accelerated tropospheric oxidation. When anthropogenic chlorine emissions were included in the model, the monthly mean concentrations of fine particulate Cl, daily maximum 1 h ClNO2, and Cl- radicals were estimated to increase by up to about 2.0 mu gm(-3), 773 pptv, and 1.5 x 10(3) molecule cm(-3) in China, respectively. Meanwhile, the monthly mean daily maximum 8 h O-3 concentration was found to increase by up to 2.0 ppbv (4.1 %), while the monthly mean NOx concentration decreased by up to 0.5 ppbv (6.1 %). The anthropogenic chlorine emissions potentially increased the 1 h O-3 concentration by up to 7.7 ppbv in China. This study highlights the need for the inclusion of anthropogenic chlorine emission in air quality modeling and demonstrated its importance in tropospheric ozone formation.