| Ozone,as one of the important pollutants affecting atmospheric environment,has been paid more and more attention.As a key link in atmospheric photochemical reaction,volatile organic compounds(VOCs)play an important role in the formation of ozone(O3).Due to the rich industrial categories,VOCs emissions are characterized by a variety of types and wide range of sources,which makes the current characteristics of industrial VOCs emissions unclear and some areas lack local emission source spectrum,so it is urgent to carry out relevant research.Through field research of industrial enterprises in Taian,this study identifies the emission characteristics of industrial VOCs in Taian,builds the emission source spectrum of industrial VOCs,defines the key components of industrial VOCs emission,and aims to provide data support and reasonable suggestions for reducing industrial VOCs emission and controlling ozone pollution,so as to improve the urban environmental air quality.This study investigated the production and pollutant discharge information of 1581 industrial enterprises in Taian in 2021.In combined with the industrial structure of Taian,23 typical industrial enterprises were selected for VOCs monitoring,and 258 VOCs samples were collected.Gas chromatography-mass spectrometry(GC-MS)was used to determine and analyze the collected gas samples.VOCs component concentrations of 14 types of industries were obtained,and VOCs emission source spectra of typical industries such as nitrogen fertilizer manufacturing,coking industry and pesticide production in Taian were constructed.Referring to online monitoring data,the total amount of industrial VOCs emissions was calculated by emission factor method,and on the basis of collating the domestic and foreign related VOCs emission source spectrum,combined with the measured emission source spectrum of local industrial enterprises,the emissions of VOCs components were calculated.The total emission source list and component source list of industrial VOCs in Taian were compiled.The characteristics of VOCs emissions in different industries and regions were analyzed,and the ozone generation potential(OFP)of industrial VOCs emissions was calculated based on the maximum incremental reactivity method.Simultaneously,Arcgis software was used to realize the spatial distribution of regional VOCs emissions and ozone generation potential of industrial sources.VOCs emission source spectrum based on enterprise outlet was obtained by monitoring VOCs emission of typical industrial enterprises on site,and then VOCs emission source spectrum of 14 industries was obtained.Nitrogen fertilizer manufacturing industry is dominated by alkanes.In the coking industry,the VOCs concentration of coke oven outlet is high,mainly alkane type,especially ethane accounts for more than 50%.Pesticide production workshop mainly halogenated hydrocarbons;The waste incineration industry is dominated by OVOC.halogenated hydrocarbon and aromatic hydrocarbon emission.The pharmaceutical industry is dominated by OVOC;The concentration of VOCs in baking process of domestic glass is high,mainly olefin and OVOC.Packaging printing industry has higher olefins,alkanes and halogenated hydrocarbons;The proportion of aromatic hydrocarbon in paint manufacturing outlet is more than 50%.The wooden furniture industry mainly emits from the painting process,which mainly contributes OVOC and aromatic hydrocarbons;The alkanes and halogenated hydrocarbons of polymer materials are higher.Alkynes and halogenated hydrocarbons are high in chemical production.The welding process of machinery manufacturing primarily emits propane.Other plastic products mainly emit alkanes;fossil fuels have different VOCs emission compositions due to the use of different fuels.The VOCs emissions of industrial enterprises were calculated by the emission factor method,and the total emission and component source list of VOCs industry in Taian were constructed.The results showed that the total VOCs emission from industrial sources in Taian was 8187.2t in 2021,with industrial VOCs emission was mainly concentrated in a few large industrial enterprises.From the perspective of spatial distribution,Ningyang County has the highest emission,Dongping County,Feicheng and Xintai have similar emission levels,followed by Daiyue District,and Taishan District has significantly lower emission levels than other districts and counties.In terms of industrial contribution,the major contributing industries are nitrogen fertilizer manufacturing and coking industry,followed by iron and steel smelting,pesticide production and waste incineration.The emissions of the above five industries are significantly higher than those of other industries.Alkane is the VOCs that contribute the most to industrial emissions,accounting for 45.8%of the total emissions,followed by halogenated hydrocarbon,olefin and aromatic hydrocarbon.From the emission characteristics of components,ethane,ethylene,propane,1.2-dichloroethane.trichloromethane,isobutane,acetylene and toluene are the major components.The maximum incremental reactivity method was used to calculate the ozone formation potential of VOCs industrial emissions in Taian.The results showed that the total ozonation potential of industrial VOCs in Taian was 2766.4kg/h.among which the contribution of olefin to ozonation was the highest.accounting for 57.0%,followed by aromatic hydrocarbons and alkanes.In terms of OFP contribution,ethylene was the largest OFP contribution species,followed by propylene,toluene,m/p-xylene,trans-2-butene,1-butene,tetrahydrofuran and ethane.In terms of OFP contribution,nitrogen fertilizer manufacturing,iron and steel smelting,coking industry,waste incineration and pesticide production are the industries with high contribution.From the perspective of regional OFP contribution.Feicheng and Xintai are the regions with high intensity.In this study,the characteristic pollutants of industrial emissions of VOCs in Taian were screened as ethane and ethylene,and the five key control industries were identified as nitrogen fertilizer manufacturing,coking industry,iron and steel smelting,pesticide production and waste incineration,and the key focus areas were pointed out as Ningyang County and Feicheng.In the process of industrial VOCs emission reduction in Taian,the above components,industries,districts and counties should take priority control of industrial emissions,which will help reduce the contribution of VOCs to ozone,reduce the frequency of ozone pollution and improve ambient air quality. |
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