Research On The Emission Characteristics Of Volatile Organic Compounds In Typical Printing Enterprises In Guangzhou

In recent years,the impact of ozone pollution on the ambient air quality of Guangzhou has been very prominent.Volatile Organic Compounds（VOCs）are one of the important precursors of ozone.The printing industry is one of the major industries that emit VOCs in Guangzhou,and it has a non-negligible impact on the atmospheric pollution of Guangzhou.This paper takes typical printing enterprises in Guangzhou as the research object,carries out research on the emission characteristics of volatile organic compounds,evaluates the environmental impact and human health impact,makes recommendations for its VOCs pollution control,and also provides references for the comprehensive pollution control of VOCs in the printing industry in other regions.The emissions of VOCs in the printing industry in Guangzhou include pre-press,printing and post-press.The concentration range of workshop VOCs is 0.7～221.93 mg/m³,the main species are aromatic hydrocarbons,alcohol ethers,esters,aldehydes and ketones;the concentration range of the exhaust pipe VOCs is 4.28～66.84 mg/m³,The main species are esters and aromatic hydrocarbons;the ambient air of the plant boundary,the average concentration of VOCs in the upwind direction is 0.56 mg/m³,and the average concentration of VOCs in the downwind direction is 2.73 mg/m³.The maximum incremental reaction activity value method and the sensory quantitative evaluation method were used to evaluate the ozone generation potential and malodorous pollution respectively.The results showed that the species with the highest ozone generation potential among the VOCs in the workshop and the exhaust pipe were aromatic hydrocarbons;ambient air at the plant boundary The threshold dilution factor of VOCs ranges from 1.8×10^-7 to 2.28,and the ethyl acetate and toluene in some enterprise boundaries arefoul-smelling.The health risk assessment model of the US EPA was used to analyze the possible human health effects of VOCs in the workshop.The results showed that none of the carcinogenic risks were involved;the HQ value of each substance ranged from 0.003 to 51.68,and the HI value of each process ranged from 0.078 to 10.26,the main non-cancer risk substance is xylene.Suggestions for VOCs Pollution Control in Guangzhou printing industry are as follows:（1）In terms of emission standards,the whole process control of VOCs emissions from the printing industry is added,and the different limits on related processes are added;strict emission concentration and rate limits;p-toluene and ethylbenzene,Xylene,ethylene glycol butyl ether and other substances that are harmful to human health and ethyl acetate,toluene and other substances that can easily cause odor pollution are subject to targeted restrictions.（2）In terms of enterprise management,environmental protection raw and auxiliary materials shall be used to avoid the use of raw and auxiliary materials containing substances with great impact on the environment and possible human health risks,and the process technology shall be improved;strengthen the management of the entire process of VOCs emissions from printing companies Strictly control the pre-printing,post-printing,storage of raw and auxiliary materials and the storage of hazardous waste;select appropriate exhaust gas treatment technology according to the characteristics of pollutants in the exhaust gas,air volume,temperature,humidity and actual working conditions;establish a ledger Management system to strengthen monitoring of exhaust emissions.