Find in Library

<p>Nonmethane volatile organic compounds (NMVOCs) are important precursors of ozone (<span class="inline-formula">O₃</span>) formation under sufficient nitrogen oxide conditions. Understanding the characteristics and emission sources of NMVOCs, as well as the relationship between NMVOCs and <span class="inline-formula">O₃</span>, is of great significance for effective <span class="inline-formula">O₃</span> pollution control. In this study, continuous online monitoring of NMVOCs was carried out in Zhengzhou, Henan, from 1–30 June. Furthermore, the study provided recommendations for strategies aimed at reducing <span class="inline-formula">O₃</span> formation. During the observation period, the concentration of total NMVOCs (TNMVOCs) varied from 9.9 to 60.3 ppbv, with an average of 22.8 <span class="inline-formula">±</span> 8.3 ppbv. The average concentration of TNMVOCs during <span class="inline-formula">O₃</span> pollution events was higher than on clean days. Six major sources of NMVOCs were identified using the positive-matrix-factorization model. Vehicular exhausts (28 %), solvent usage (27 %), and industrial production (22 %) were the main sources. We explore the <span class="inline-formula">O₃</span>–precursors relationship and propose observation-oriented <span class="inline-formula">O₃</span> control strategies. The results of the relative incremental reactivity (RIR) and the Empirical Kinetics Modeling Approach show that Zhengzhou was under an anthropogenic volatile organic compound (AVOC)-limited regime. NMVOCs had the largest RIR value, while <span class="inline-formula">NO_<i>x</i></span> exhibited a negative RIR value. It is noteworthy that the sensitivity of <span class="inline-formula">O₃</span> formation to biogenic volatile organic compounds (BVOCs) was greater than that to AVOCs. Considering the reduction effect, it is recommended that the ratio of AVOCs to <span class="inline-formula">NO_<i>x</i></span> be maintained at no less than <span class="inline-formula">3:1</span> to effectively reduce <span class="inline-formula">O₃</span> formation.</p>