在2013-2017年期间,中国主要地区的PM2.5浓度急剧下降,而O3则有所增加。因此,迫切需要制定协同的区域PM2.5和O3控制策略。本研究建立了排放-浓度响应面模型,并基于空气效益和成本与达到评估系统(ABaCAS)的框架,提出了长江三角洲(YRD)PM2.5和O3控制的协同途径。结果表明,氮氧化物的区域排放,SO2,NH3,VOCs(挥发性有机化合物)和初级PM2.5应降低18%,23%,14%,17%和33%,与2017年相比,在2025年实现PM2.5和O3的25%和5%的下降,并且减排比例将需要50%,26%,28%,28%和55%达到国家环境空气质量标准。为了有效减少YRD中东部的O3污染,需要加强VOCs控制,使O3减少5%,然后应加速NOx还原以达到空气质量。同时,应优先控制PM2.5的排放,以解决YRD北部严重的PM2.5污染。对于YRD的大多数城市来说,春季和秋季VOCs减排率应高于NOx减排率。当出现强烈的VOC限制制度时,应在夏季而不是冬季增加NOx控制。此外,关于工业过程的排放控制,优先考虑道路车辆和住宅来源,扩大联合控制区域,包括山东,江西和湖北对O3进行有效控制。
PM2.5 concentrations have dramatically reduced in key regions of
China during the period 2013-2017, while O3 has increased. Hence there is an urgent demand to develop a synergetic regional PM2.5 and O3 control strategy. This study develops an emission-to-concentration response surface model and proposes a synergetic pathway for PM2.5 and O3 control in the Yangtze River Delta (YRD) based on the framework of the Air Benefit and Cost and Attainment Assessment System (ABaCAS). Results suggest that the regional emissions of NOx, SO2, NH3, VOCs (volatile organic compounds) and primary PM2.5 should be reduced by 18%, 23%, 14%, 17% and 33% compared with 2017 to achieve 25% and 5% decreases of PM2.5 and O3 in 2025, and that the emission reduction ratios will need to be 50%, 26%, 28%, 28% and 55% to attain the National Ambient Air Quality Standard. To effectively reduce the O3 pollution in the central and eastern YRD, VOCs controls need to be strengthened to reduce O3 by 5%, and then NOx reduction should be accelerated for air quality attainment. Meanwhile, control of primary PM2.5 emissions shall be prioritized to address the severe PM2.5 pollution in the northern YRD. For most cities in the YRD, the VOCs emission reduction ratio should be higher than that for NOx in Spring and Autumn. NOx control should be increased in summer rather than winter when a strong VOC-limited regime occurs. Besides, regarding the emission control of industrial processes, on-road vehicle and residential sources shall be prioritized and the joint control area should be enlarged to include Shandong, Jiangxi and Hubei Province for effective O3 control.