Petrochemical and Industrial Sources of Volatile Organic Compounds Analyzed via Regional Wind-Driven Network in Shanghai

Wanyi Qiu,Shule Li,Keding Lu,Yuhan Liu

doi:10.3390/atmos10120760

Abstract

Due to the development of industrialization and urbanization, secondary pollution is becoming increasingly serious in the Yangtze River Delta. Volatile organic compounds (VOCs) are key precursors of the near-surface ozone, secondary organic aerosol (SOA), and other secondary pollutants. In this study, we chose a serious ozone pollution period (01 May–31 July 2017) in Jinshan, which is a petrochemical and industrial area in Shanghai. We explored the VOCs distribution characteristics and contribution to secondary pollutants via constructing a regional network based on wind patterns. We determined that dense pollutants were accumulated at adjacent sites under local circulation (LC), and pollution from petrochemical discharge was more serious than industry for all sites under southeast (SE) wind. We also found that cyclopentane, o-xylene, m/p-xylene, 1-3-butadiene, and 1-hexene were priority-controlled species as they were most vital to form secondary pollutants. This study proves that regional network analysis can be successfully applied to explore pollution characteristics and regional secondary pollutants formation.

Highlights

Volatile organic compounds (VOCs) are major participants in atmospheric photochemical processes and key precursors for the formation of near-surface ozone, secondary organic aerosol (SOA), and other secondary pollutants [1,2]
OH radicals were not measured in this study, the OH exposure could be estimated from the decline in concentration of VOCs by Equation (2) derived from ct =co e−ki[OH]t [61,62], after correcting for physical dilution: ln[(ci (r) ⁄ ci (s)] = ln D(t) + OH·∆t·ki where ci (s) refers to the original concentration at the source site, which is the highest value during the nighttime at WL when photochemical reactions are considered to be the weakest, and are most reflective of the initial emissions [63]
The coupling of regional network observations was exploited to determine the effect of primary sources, namely the Complex and Second Industrial Zone, on the surrounding area

Summary

Introduction

Volatile organic compounds (VOCs) are major participants in atmospheric photochemical processes and key precursors for the formation of near-surface ozone, secondary organic aerosol (SOA), and other secondary pollutants [1,2]. The total amount of anthropogenic VOCs discharged in China was 25.03 million tons in 2015 [9], and air pollution has shifted from single to compound photochemical pollution. Industrial emissions, especially unorganized solvent, paint, and petrochemical emissions, account for the largest sources of anthropogenic VOCs [10,11,12]. As for regional emissions, the Yangtze River Delta (YRD) shows the highest emissions, and has the highest contribution to ozone and SOA formation nationwide [9,13]. Huang et al [10]

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Discussion

Conclusion