基于WRF-Chem的长三角地区PM_(2.5)和O_(3)污染协同控制研究

Study on the synergistic control of PM_(2.5) and O_(3) pollution in the Yangtze River Delta region based on WRF-Chem model

以PM_(2.5)和O_(3)浓度超标为表征的区域性大气复合污染已成为当前我国大气污染的主要问题,严重影响到经济的发展和社会的和谐,探究PM_(2.5)与O_(3)的协同控制近年来成为大气污染防控的热点.本文基于WRF-Chem模式,结合气象、大气污染物观测数据及MEIC排放清单等数据,依据不同比例的NO_(x)和VOCs减排量,设计了36组减排情景,模拟了长三角地区PM_(2.5)和O_(3)复合污染时段的空气质量状况.同时,利用综合经验动力学(CEKMA)方法,综合考虑NO_(x)和VOCs减排的边际效益成本和环境健康效益,评估了长三角地区NO_(x)及VOCs减排对PM_(2.5)和O_(3)大气污染控制的影响.最后,定性并定量地研究两者的协同关系及协同减排效果,给出了该区域在复合污染情景下的先侧重VOCs、后侧重NO_(x)减排的协同优化路径,采取先减少NO_(x)排放约70%(或60%)且减少VOCs排放约10%(或20%),再削减剩余VOCs及NO_(x)排放量的方案,减排的环境空气质量改善效率可以分别达到最优路径的90%(或80%)以上,而等比例同时减排NO_(x)和VOCs对区域空气质量的改善反而是效果不佳的减排方案之一.研究方法和结论对区域大气环境的综合治理具有重要的应用价值,对我国其他地区的大气污染防治及相关研究也具有借鉴意义.

Regional compound air pollution,characterized by high levels of PM_(2.5) and O_(3) concentrations,has become the main problem of air pollution in China,posing a severe threat to economic development and social peace.The synergistic management of PM_(2.5) and O_(3) has been a hot topic in air pollution prevention and control in recent years.In this paper,combining meteorological and air pollution monitoring data with MEIC emission inventory data,36 sets of emission reduction scenarios based on different proportions of NO_(x)and VOCs emission reductions were designed using the WRF-Chem model to simulate the air quality conditions of PM_(2.5) and O_(3) compound pollution in the Yangtze River Delta region.The impact of NO_(x)and VOCs emission reduction on PM_(2.5) and O_(3) air pollution control in the Yangtze River Delta region was evaluated using the Combined Empirical Kinetics Modeling Approach method(CEKMA)by considering the marginal benefit-cost and environmental health benefits of NO_(x)and VOCs emission reduction.The synergistic interaction and emission reduction impacts were also investigated qualitatively and quantitatively given a strategy that prioritizes the reduction of NO_(x)before moving on to VOCs emissions which is the region's optimal NO_(x)and VOCs emission reduction strategy under the composite pollution scenario.It should be noted that by reducing NO_(x)emissions by about 70%(or 60%)and VOCs emissions by about 10%(or 20%)before reducing the remaining VOCs and NO_(x)emissions,the ambient air quality improvement efficiency of the emission reduction can reach more than 90%(or 80%)of the optimal pathway,whereas reducing NO_(x)and VOCs in equal proportions at the same time is ineffective for regional air quality improvement.The findings and methods of the study are also useful for air pollution prevention and control,as well as comparable studies in other areas of China.