降低佛山市臭氧高质量浓度的数值模拟

Numerical simulation study on reducing high O3 concentration in Foshan

选取珠江三角洲中心城市佛山市作为主要研究区域,利用区域空气质量数值模式(WRF/CMAQ)结合敏感性试验的方法开展臭氧污染削峰减排研究。利用WRF/CMAQ模式开展不同的敏感性试验,包括减少影响臭氧质量浓度的两类前体物VOCs和NO x的总排放量、分别减少佛山市交通行业、溶剂行业和其他工业(不包括溶剂行业)的排放量。结果表明佛山市的臭氧污染属于VOCs敏感,对VOCs进行减排能在一定程度上降低臭氧质量浓度,VOCs减排30%后臭氧日峰值最高可降低约10%,而对NO x进行减排反而会造成部分地区臭氧质量浓度的增加。对交通和工业行业排放进行削减会同时减少VOCs和NO x的排放,因此对这两个行业的减排会导致不同地区的臭氧质量浓度有增有减。溶剂行业的主要排放物种是VOCs,对溶剂行业的减排可以显著降低臭氧峰值质量浓度,因此溶剂行业是臭氧削峰减排的重点。本研究还开展了提前不同天数进行减排的敏感性试验,结果显示:在佛山市提前1 d的减排效果比当天减排效果好,而与提前2 d或3 d的减排效果差别不大,因此在佛山这样的城市范围内,当地提前1 d减排即可得到最有效、最经济的臭氧削峰减排效果。

The regional air quality model WRF/CMAQ combined with sensitivity tests was used to study the reduction of ozone pollution peak in Foshan,a city in the center of the Pearl River Delta(PRD).Sensitivity tests based on the WRF/CMAQ model included reducing the emissions of two O 3 precursors(VOCs and NO x)and reducing the emissions from traffic,industries(excluding solvents),and solvents in Foshan,respectively.The results showed that the ozone pollution in Foshan City was most sensitive to VOCs.Reducing the emission of VOCs by 30%decreased the ozone peak concentration by up to about 10%.However,the reduction of NO x emissions increased the ozone concentrations in some areas.Reduction in emissions of traffic and industrial sectors led to increase or decrease of ozone concentrations in different areas because VOCs and NO x emissions were reduced simultaneously.The major emission species in the solvent industry were VOCs.It could significantly decrease ozone peak concentration when reducing the emissions of the solvent industry.Therefore,the solvent industry was the key sector of ozone peak reduction.This study also conducted sensitivity tests of reducing emissions for different days ahead.The results showed that the effects of reducing emission for 1-day in advance were better than 0-day but not significantly different from 2-day and 3-day in advance.In conclusion,reducing emissions 1-day in advance was the most effective and economical control strategy to reduce the peak of ozone in Foshan city area.