Quantification for photochemical loss of volatile organic compounds upon ozone formation chemistry at an industrial city (Zibo) in North China Plain

Wenting Wang; Zhensen Zheng; Yanhui Liu; Bo Xu; Wen Yang; Xiaoli Wang; Chunmei Geng; Zhipeng Bai

doi:10.1016/j.envres.2024.119088

Quantification for photochemical loss of volatile organic compounds upon ozone formation chemistry at an industrial city (Zibo) in North China Plain

Environ Res. 2024 May 18:256:119088. doi: 10.1016/j.envres.2024.119088. Online ahead of print.

Authors

Wenting Wang¹, Zhensen Zheng², Yanhui Liu³, Bo Xu⁴, Wen Yang⁵, Xiaoli Wang⁶, Chunmei Geng⁷, Zhipeng Bai³

Affiliations

¹ State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; College of Environmental Science & Safety Engineering, Tianjin University of Technology, Tianjin, 300384, China.
² University of Innsbruck, Institute of Ion Physics and Applied Physics, 6020, Innsbruck, Austria.
³ State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
⁴ Zibo Eco-Environment Monitoring Center, Zibo, 255000, China.
⁵ State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China. Electronic address: yangwen@craes.org.cn.
⁶ College of Environmental Science & Safety Engineering, Tianjin University of Technology, Tianjin, 300384, China.
⁷ State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China. Electronic address: gengcm@craes.org.cn.

PMID: 38768881
DOI: 10.1016/j.envres.2024.119088

Abstract

Volatile organic compounds (VOCs) are consumed by photochemical reactions during transport, leading to inaccuracies in estimating the local ozone (O₃) formation mechanism and its subsequent strategy for O₃ attainment. To comprehensively quantify the deviations in O₃ formation mechanism by consumed VOCs (C-VOCs), a 5-month field campaign was conducted in a typical industrial city in Northern China over incorporating a 0-D box model (implemented with MCMv3.3.1). The averaged C-VOCs concentration was 6.8 ppbv during entire period, and Alkenes accounted for 62% dominantly. Without considering C-VOCs, the relative incremental reactivity (RIR) of anthropogenic VOCs (AVOC, overestimated by 68%-75%) and NO_x (underestimated by 137%-527%) demonstrated deviations at multiple scenarios, and the RIR deviations for precursors in High-O₃-periods (HOP) were lower than Low-O₃-periods (LOP). The RIR deviations from individual species involved C-VOCs calculation did not impact the identification for the high-ranking-RIR AVOC species but non-negligible. Monthly comparisons showed that higher C-VOCs concentrations would lead to higher RIR deviations. The daily maximum of net O_x production rate (P(O_x)) and the regional transport O_x (Trans(O_x)) without C-VOCs were underestimated by 56%-194% and 81%-243%, respectively. After considering C-VOCs, the contribution of HO₂+NO for O_x gross production (G(O_x)) decreased by 7% (LOP) and 7% (HOP), but OH + NO₂ for O_x destruction (D(O_x)) decreased by 16% (LOP) and 23% (HOP), and alkenes + O₃ increased for D(O_x) by 12% (LOP) and 22% (HOP). This implies that VOCs-NO_x-O₃ sensitivity was deviated between with/without C-VOCs, and severe O₃ pollution rendered deviations in O₃ formation, especially via NO_x-driving chemistry. Based on RIR(NO_x)/RIR(AVOC) with/without C-VOCs, the sensitivity regime shifted from VOCs-limited (-0.93) to transition (1.38) at LOP, and from VOCs-limited (0.19) to NO_x-limited (3.79) at HOP. Our results reflected that the NO_x limitation degree was underestimated without constraint C-VOCs, especially HOP, and provided implication to more precise O₃ pollution control strategies.

Keywords: MCMv3.3.1; Ozone formation chemistry; Photochemical loss; RIR; Volatile organic compounds (VOCs).

Publication types

Letter