Effects Of VOCs Emission Duing Organic Liquid Loading And Unloading Processes On The Environment And Human Health

In recent years,it is prominent impact of ozone pollution on ambient air quality across the country,volatile organic compounds（VOCs）is one of the important precursors of ozone.National documents point out that enterprises need to control VOCs pollution in 10 key aspects such as storage tanks,loading and unloading,and open liquid surfaces of volatile organic liquids,which shows that need to control the organic liquid loading and unloading process.In this paper,it selects six typical enterprises in an industrial park to study the characteristics of VOCs emission from organic liquid loading and unloading process to evaluate the impact of VOCs emission on the environment and human health.At last,it make suggestions for VOCs pollution control in organic liquid loading and unloading process and provide references for VOCs comprehensive pollution control in other regions.The VOCs emissions from loading and unloading process caused by poor sealing of inlet and discharge components,top feed holes and manholes of tankers.In order to further quantify the pollution to the environment,it samplings in up and downwind of the loading and unloading area,and it used to evaluate the environmental impact of VOCs by maximum incremental reaction activity value method and source activity.The substances emitted during the loading and unloading process were mainly olefins（41.57%）and aromatic hydrocarbons（34.97%）,followed by oxygenated hydrocarbons（10.63%）,alkanes（8.23%）,halogenated hydrocarbons（3.81%）and alkynes（0.78%）;the highest VOCs emission concentrations were 407.5μg/m³in TC chemical;the contribution of VOCs to ozone generation potential from loading and unloading in six typical enterprises was:olefins（74.17%）>aromatic hydrocarbons（21.84%）>oxygenated hydrocarbons（1.42%）>alkynes(（1.29%）>alkanes（1.22%）>halogenated hydrocarbons（0.07%）;the average SR of VOCs emitted from the loading and unloading of organic liquids is 2.33 times higher than the average SR of VOCs emitted from the production process of other enterprises,and it cannot be ignored the environmental impact of VOCs emission from this process.It was assessed the potential human health impact of VOCs at operating and resting positions of workers during loading and unloading process by the US EPA health risk assessment.The results showed that benzene and olefins were the highest carcinogenic risk to humans.The benzene in YY-5 was the highest carcinogenic risk to humans of 9.22 times the standard value of 1×10^-4.The non-carcinogenic risk indices of GQ-2,GQ-3,YY-4 and YY-5 were 1.59,2.15,6.14 and 4.07 times of 1.The carcinogenic and non-carcinogenic risks to humans from VOCs emissions from the loading and unloading of other enterprises are within the safety evaluation thresholds.In addition,the risks to human health from1,2-dichloroethane and trichloromethane in ambient air cannot be ignored.