Atmosphere Pollution With Polycyclic Aromatic Hydrocarbons And Total Suspended Particles In The East Of Nanjing

Polycyclic aromatic hydrocarbons(PAHs)are a group of persistent organic contaminants.Because they are strongly hydrophobic,highly lipotropy,and toxic,The PAHs can be easily absorbed and accumulated in the organisms,resulting in carcinogenicity,teratogenicity,and mutagenicity.PAHs distribute widely in water,soil,and atmosphere.Especially,with the development of modern industry,the utilization of coal,natgas,and petroleum has produced a large number of PAHs and suspended particles in atmosphere.These will cause seriously physical and mental troubles.It is thus that PAHs and suspended particles have rasied the widely public attention.The PAHs in the atmosphere mainly exist in the formation of gas phase and particulate phase.The gasoloids with PAHs,mainly containing in the high ring of highly toxic PAHs,have a greater impact on human health.In recent years,the fog and haze have frequently occurred in China.The gas phase and particulate phase in fog and haze is a "timebomb"which threatens the citizen's health.Nevertheless,the extent,source,and type of the PAHs in Nanjing city,China have been unknown;and the releationship between gas phase PAHs and particulate phase is also unclear.This paper improves the detection method of gas phase and particulate phase PAHs from the atmosphere,and regular monitors PAHs in the atmosphere in the East of Nanjing.We studied the seasonal variation of PAHs in the atmosphere,and determined the source of them.At the same time,total suspended particulate(TSP)matter and the surface dust was determined,and the relationships between PAHs and TSP concentrations were further discussed.(1)Optimize extraction and detection method of atmospheric gaseous and particulate phase PAHs by gradient elution and dual wavelength.Atmospheric particulate-phase PAHs were collected by glass fiber filter,with 100 L/min of flow rate,4 h each time.The glass fiber filter samples were dried and using dichloromethane to extract the PAHs on it,dry this samples by nitrogen concentration,then constant volume to 1 ml,after 0.22?m aperture membrane filtration and HPLC/UV analysis.The recovery rate of 16 PAHs of the method was 50%-110%,the RSD is less than 10%.Gas phase PAHs was collected by XAD-2,with flow rate of 1 L/min for 4 h each time.Then put the samples in 4? refrigerator.The extraction method was the same as above.Experiments show that the recovery rate of 16 PAHs was between 50%-110%,the majority of up to 80%-100%,and the RSD is less than 9.16%.(2)We study the atmosphere pollution with PAHs characteristics in the east of Nanjing city.The data showed concentration of atmospheric gas phase and particulate phase PAHs was seasonal,highest in winter,followed autumn and lowest in spring.The data of BaP showed that the proportion of high molecular PAHs increased in winter,especially the gas phase PAHs.The concentration of BaP at 0.6 ?g/m3 was further above the national standard.The data showed most of atmosphere PAHs was gas phase PAHs,it concentration was 10-20 ?g/m,and particulate phase PAHs concentrations was around 0.05-0.1 ?g/m.The study showed,most of gas phase PAHs was low rings,and particulate phase PAHs was high rings.The source of atmosphere PAHs was identified by ratio method,the results showed that coal and gasoline combustion is the main source of PAHs pollution in the atmosphere of Nanjing city.(3)Study on relationship among atmosphere PAHs,TSP and surface dust.The concentration of atmosphere TSP in the east of Nanjing city was seasonal,winter was higher than other seasons.But the data was often appeared in the higher concentration of TSP in the other seasons,as the TSP was effected by short-term weather and human activities.The TSP was significant correlation with particulate phase PAHs(P<0.05),it mean that when the TSP concentration increased,the concentration of particulate phase PAHs will also rise.There was no significant association between TSP and gas phase PAHs(P>0.05).The data showed that concentration of PAHs in surface dust was seasonal,highest in winter and lowest in spring.In winter,the amount of PAHs in surface dust was significantly increased,and the high rings PAHs ratio has increased.It was the same as the characteristics of atmospheric PAHs.