Study On Polybrominated Diphenyl Ethers Atmosphere Wet And Dry Deposition Characteristics In Harbin

Polybrominated diphenyl ethers(PBDEs)are brominated fire retardants,and also belong to persistent organic pollutants(POPs).These chemical are added to commercial products,such as furniture,electronics,and construction materials to reduce their flammability.PBDEs can easily emit to air from the products.Dry and wet deposition are two effective ways to washout PBDEs in the atmosphere,but also the bridges connecting the atmosphere-water environment and atmosphere-soil environment.In China,the study on the dry and wet deposition have been carried out by scientistes,but the research has far away from comprehensive.For example,data for snow deposition characteristics and dry deposition pollution levels are lacking.In order to fill these gaps,in this study,air samples of both gas and particle phases,samples of dry deposition,rain and snow samples were collected for one year from March,2016 to February,2017.Concentrations in particle dry deposition,rain and snow samples and air samples,composition characters,sources,dry deposition characteristics and wet deposition characteristics of PBDEs have been analyzed.The Chemical Partitioning Space Map(CPSM)was used to analyze the PBDEs distribution in different phases depositions.All of the samples collected,including air,dry deposition,rain drops,and snowflakes,have been pretreated,measured and analyzed.In this study,eight PBDEs congeners of(BDE-28,BDE-100,BDE-99,BDE-85,BDE-154,BDE-153,BDE-138,BDE-183)have been detected in all of the samples,but detective rate were different in all samples.The detective rate of BDE-154 were 52% in rain dissolved phase,and 45% in rain particle phase.The detectived rate of BDE-138 was 79% in rain particle phase.For other congeners detectived rate were higher than 90% in different phase.The concentrations in air,particle dry deposition,rain,and snow samples were 44.71±19.59 pg·m-3,360.80±357.44 ng·g-1,25.87±14.77 ng·L-1 and 18.44±8.64 ng·L-1 respectively.Compared with reported data,the pollution levels reported in this study were in the middle level.Principal component analysis(PCA)was applied to analyze the source of PBDEs in air,particle dry deposition,rain and snow.The sources of PBDEs were mainly from commercial penta-BDE and octa-BDE.PBDE dry deposition fluxes were 23.35±12.74 pg·m-2·h-1 for gas phase and 44.82±18.49 ng·m-2·day-1for particle phase with distinct seasonal variation.The particle dry deposition velocity was estimated to be 1.69±0.93 cm·s-1,which was medium compared with other reported results in the world.The rain and snow washout ratios for the 8 PBDE congeners ranged from 2.78×104±3.28×103 for BDE-154 and 2.57×106±3.30×106 for BDE-85 with an average of 7.60×105±6.25×105 for ?8PBDEs,close to the data used by the modelers.The average PBDEs rain and snow deposition fluxes were 12.97±2.09 and 6.29±2.72 ng·m-2·h-1,which in the midium levelsin comparison to the reported data.The PBDEs Chemical Partitioning Space Map(CPSM)was uesed to simulate and predict the distrubution of PBDEs in the different deposition while raining.The lower molecular weight congeners were mainly existing in the gas phase dry deposition while raining,the higher molecular weight monomers were mainly existing in the partilce dry deposition and particle wet deposition while raining.