Emission Characteristics and Concentration Prediction of Polycyclic Aromatic Hydrocarbons(Pahs)in Particulate Matter PM1.0 Released By the Buring of Moxa Sticks and Pillars
To understand the emission characteristics of Polycyclic Aromatic Hydrocarbons(PAHs)in PM1.0 released from the combustion of moxa sticks and moxa pillars,four types of moxa sticks and two types of moxa pillars with different storage years and purification ratios were selected as the research objects.A specific quantity of moxa sticks or moxa pillars were firstly ignited in an 8 m3 clean environment chamber with an air change rate of 1/h.Upon completion of the combustion and cessation of ventilation,PM1.0 was sampled in the smoke.The samples were analyzed using purification and GC-MS online to determine the PAHs content in PM1.0.From the PAHs content,the highest concentration of PAHs in PM1.0(PM1.0(PAHs))was determined from the combustion of moxa sticks or moxa pillars,and then the emission factor and the emission rate were determined to analyze the influence of the inherent characteristic parameters of moxa sticks or moxa pillars on the dispersed PAHs,and at the same time,to make a comparative analysis with the characterization of the PAHs dispersal in PM2 5 from the literature.The toxicity of(PM1.0)PAHs emitted by moxa sticks and moxa pillars was analyzed,and the concentration of(PM1.0)PAHs in the actual moxa chamber with different volumes and air change rate was then predicted by simulation.The results showed that:1)The dominant individuals in the(PM1.0)PAHs released from the combustion of moxa sticks and pillars were mainly phenanthrene,anthracene,and fluoranthene,with an average of 23.66％for phenanthrene.4 rings PAHs(Fluoranthene,Pyrene,Benzo[a]anthracene,and Chrysene)had the highest percentage,ranging from 31.11％to 61.49％.5 rings(Benzo[b]fluoranthene,Benzo[k]fluoranthene,Benzo[a]pyrene,and Dibenzo[a,h]anthracene)and 6 rings(Indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene)accounted for a relatively small proportion of the total and increased with increasing purification ratio or decreasing storage year.2)The emission factors of(PM1.0)PAHs were 2.99 μg/g and 4.62 µg/g,respectively,for moxa sticks or moxa pillars,and the mean values of emission rate were 6.51 µg/(h·g)and 26.79 p.g/(h·g),respectively.The emission factor and emission rate tended to increase with decreasing storage year and purification ratio.3)The emission factors of(PM1.0)PAHs in(PM2.5)PAHs ranged from 78.90％to 85.28％,and the emission rate ranged from 78.91％to 85.15％,and the percentage of high ring PAHs in(PM1.0)PAHs was higher than that in(PM2.5)PAHs.4)The carcinogenic toxicity equivalent dose of(PM1.0)PAHs ranged from 107.14 to 526.56 ng/g,and the equivalent dose of mutagenicity is 110.12～585.62 ng/g.The toxicity contribution of 5～6 rings PAHs is the highest.Controlling the emission of toxic dominant individuals,such as benzo[a]pyrene,can effectively reduce the risk of toxicity.5)Increasing either the air change rate or the room volume reduced the benzo[a]pyrene concentration.The peak concentrations of benzo[a]pyrene were 2.75 ng/m3 and 4.69 ng/m3 for moxa sticks and moxa pillars,respectively,in a room of 60 m3 with an air change rate of 12/h.The peak concentrations of benzo[a]pyrene were 5.19 ng/m3 and 8.36 ng/m3 in a room with an air change rate of 6/h.It is recommended to perform moxibustion with moxa sticks in a ventilation condition with 12/h.
万方数据
维普
