| In recent years,severe air pollution occurred frequently in China.Composite atmospheric pollution problems,with a significant component of pollution such as PM2.5 and ozone,have become increasingly prominent.Volatile organic compounds?VOCs?which are identified to be important precursors of PM2.5 and ozone play a significant role in atmospheric chemical reactions.The wooden furniture manufacturing industry is a typical industry with high pollution,low added value,relatively backward technology and low pollution control level.In the process of wooden furniture manufacturing,we use a large number of paints and adhesives which emit a great quantity of VOCs.The wooden furniture manufacturing industry is a key industry for the control of VOCs in China.In this study,wooden furniture manufacturing industry was chosen as the object.VOCs emission characteristics and control techniques of wooden furniture manufacturing industry has been studied in this work,which could be helpful for Chinese governments when formulating VOCs pollution control policy of wooden furniture manufacturing industry.The main processes of VOCs emission in wooden furniture manufacturing is coating and adhering.The minimum concentration of VOCs in production workshop is 21.95 mg/m3 while the maximum concentration is 204.50 mg/m3.The largest proportion of VOCs in production workshop are aromatic hydrocarbons,followed by esters,aldehydes and ketones,alkanes and alcohols and ethers.The concentration of VOCs in stack ranges from 36.77 to 251.29 mg/m3,the main species in stack are aromatic hydrocarbons,esters,aldehydes and ketones and alkanes.The average concentration of VOCs at the boundary of the workshop is 30.95 mg/m3,the main species are aromatic hydrocarbons and esters.The average concentration of VOCs at the boundary of the factory is 0.88 mg/m3,the main species are aromatic hydrocarbons,halogenated hydrocarbons,esters and aldehydes and ketones.The MIR method and the FAC method were used to estimate the ozone generation potential and the secondary organic aerosol generation potential respectively.The results show that the most important contributors of the VOCs in the workshop and the stack to these two generation potentials are aromatic hydrocarbons.The threshold dilution multiples was used to estimate the malodor contribution of each substance.The results showed that the threshold dilution multiple of each VOC substance at the workshop boundary ranged from 7.02×10-5 to1.24×103,and more than ten kinds of substances such as sec-butyl acetate,m-xylene,butyl acetate,butanol and n-butanol are the main contributors to the foul odor of the workshop boundary;the VOCs at the factory boundary produce almost no odor pollution.The available control technologies for VOCs in the whole process of wooden furniture manufacturing are as follows:first,use low VOC raw and auxiliary materials such as water-based paints,UV-curable paints and water-based adhesives or raw and auxiliary materials without VOCs,and improve the production process.Next,strengthen the process control,reduce the loss of raw and auxiliary materials and the unorganized emissions.Finally,use pretreatment techniques like dry filter,then use treatment techniques such as carbon adsorption,and carbon or zeolite wheel adsorption combined with combustion. |
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