| In recent years, city clusters in China have been experincecing sever regional airpollutions characterized by high levels of PM2.5and Ozone (O3). Volatile Organic Compounds(VOCs) is indepensible precursor in the formation of photochemical O3and PM2.5.VOCsinclude hundereds of individual species, each of which has different reactivity. Researcheshave shown that reactivity-based control strategy is more effective than mass-based strategyin secondary pollution control. However, research to support the formulation ofreactivity-based control strategy in China is still rare.Reliable emission inventory and local source profiles are foudations of the developmentof speciated VOCs emission inventory and reactivity-based control strategy. In this study, thereliability of emission inventory was first evaluated by receptor modeling to identify themajor VOCs emission sources in the PRD region. Second, by field measurements andliterature review, local emission source profiles for the major VOCs emission sources in PRDwere established. Third, anthropogenic and biogenic speciated VOCs emission inventory forthe PRD region in2010were developed and Ozone Formation Potentials (OFPs) wereestimated to identify the key VOCs species and emission sources for emission control.Results showed that (1) Mixed solvent usage, gasoline exhaust and industrial processwere the major VOCs emission sources identified by both emission inventory and receptormodeling. Discrepancies in the contributions of LPG source, solvent usage and biogenicsource between emission inventory and receptor modeling were observed, which might beattributed to the numbers of quantified species, used tracers, and effect of photochemicalreaction loss in receptor modeling as well as the inherent uncertainties of emission inventory.(2) Based upon field measurements and literature data mining, local emission sources profilesof the major VOCs emission sources, including mobile sources (light-duty gasoline vehicles,light-duty diesel vehicles, LPG vehicles and motorcycles), industrial solvent usage(furniture-making, shoe-making, printing, metal surface coating and PCB manufacturing),non-industrial solvent usage (architectural paints and consumer product) were established.(3)Isoprene, methyl alcohol, toluene, benzene, acetone, ethene, m/p-xylene and ethylbenzenewere the eight top emission contributing species, while isoprene, ethene, m/p-xylene, propene, toluene,1,2,4-trimethylbenzene, m-ethyltoluene and1,2,3-trimethylbenzene were the eighttop OFP contributing species.(4)76.4%anthropogenic OFP were contributed by m/p-xylene,ethene, toluene,1,2,4-trimethylbenzene, propene and another15species. Among these highOFP contributing species, propene,1,2,3-trimethylbenzene,1,3,5-trimethlybenzene,trans-2-butene and1-ethyl-2,3-dimethylbenzene were high reactivity species with MIR largerthan10and toluene, o-xylenes, styrene and benzene were toxi air pollutants, which should becontrolled with priority.(5) For anthoropgenic sources, their contributions to emission andOFP were generally consistent. Industrail solvent usage, gasoline vehicles, motorcycles andindustrial process were the major anthropogenic sources, contributing32.9%,19.5%,14.5%and13.5%to the anthropogenic OFP. Electronics manufacturing and furniture-making werethe major contributing industrial solvent usage sectors while pharmacy, plastic product,chemical fiber, petroleum refining and pulp manufacturing were the major contributingindustrial process sectors.(6) The VOCs control strategy in the PRD region should pay moreattentions to electronics manufacturing, pharmacy, plastic product, chemical fiber and pulpmanufacturing. And there is great need to incorporate the current mass-based control with thereactivity-based control strategies. |
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