Temporal and spatial discrepancies of VOCs in an industrial-dominant city in China during summertime.

Ozone (O) pollution is currently problematic to cities across the globe. Many non-methane hydrocarbons (NMHCs) are efficient O precursors. In this study, target volatile organic compounds (VOCs), including oxygenated VOCs (known as carbonyls), were monitored at eight sampling sites distributed in urban and suburban in the typical and industrial-dominant city of Shaoxing, Zhejiang province, China. At the suburban sites, C-C alkanes, aromatics with lower reactivity (k <13 × 10 cm mol s) and acetonitrile were more abundant than urban ones due to higher emissions from diesel-fueled trucks and biomass burning. In general, higher abundances of total quantified NMHCs (ΣNMHC) were found on high O (HO) days. The increments of formaldehyde (C) and O were higher in urban than suburban, while a reverse trend was seen for acetaldehyde (C). Substantial and local biogenic inputs of C were found in suburban in the afternoon when both temperature and light intensity reached maximum of the day. In urban, higher increment was found for O than the carbonyls, representing that the secondary formation of O was more efficient. Distance decay gradient of most representative NMHCs were positively correlated to the distances from a westernmost industrial origin located at the upwind location. The net loss rates of the NMHCs ranged from -0.009 to -0.11 ppbv km, while the higher rates were seen for the most reactive species like C-C alkenes. The results and interpretation of this study are informative to establish efficient local control measures for O and the related percussors for the microscale industrial cities in China.