| This paper is divided into two parts.The first part based on the Chinese scientific expedition voyage to the Antarctic and atmospheric aerosol samples collected from Great Wall Station and Zhongshan Station in Antarctica were taken as the object.We analysised organic molecules aerosol concentration,change and source characteristics at the regional atmospheric boundary layer.The main molecular markers studied include fatty family compounds（n-alkanes,fatty alcohols and fatty acids）,carbohydrate compounds,sterols,lignin and resin products,polar organic acids（aromatic acids and polyacids）,phthalate esters,biogenic secondary organic aerosols（SOA）tracers and polycyclic aromatic hydrocarbons.The atmospheric aerosol samples collected from the Great Wall Station and Zhongshan Station in Antarctica from February,2015 to December,2015 were analyzed by organic solvent extraction,derivatization and GC/MS.The concentrations of more than 100 organic compounds in 11 categories were determined.The concentrations of total organic compounds at Great Wall Station ranged from 0.1996to 107.7089 ng m-3,with an average of 7.1688 ng m-3.The concentrations at Zhongshan Station ranged from 0.2858 to 60.9206 ng m-3,with an average of 11.6327ng m-3.The total amount and average value of organic compounds at Great Wall Station were lower than those at Zhongshan Station,and most compounds at Great Wall Station were lower than those at Zhongshan Station in addition to n-alkanes and phthalates.The lipid compounds（n-akanes,fatty acids and fatty alcohols）is the main aerosol organic compounds,followed by sugars,sterols and phthalates.Lignin and resin products,organic acids and biogenic SOA tracers have the lowest concentrations.The source analysis of organic matters showed that the Marine and microbial sources were the main sources of organic compounds in the atmospheric aerosol of the scientific research station,and their relative contributions accounted for 1/2 of the total organic matter sources.The order of contributions was the Marine and microbial sources>wax source of higher plants>burning sources of fossil fuels such as petroleum>primary biological origin>biomass burning source>secondary oxidation.The contributions of organic aerosols sources were also different in different periods.During T1～T3,Marine and microbial sources,higher plant wax sources and terrestrial biological sources were the main sources.During T4,the burning of fossil fuels such as petroleum became the main source of organic compounds in the aerosol of the station,contributing up to 70%,indicating the important impact of human activities on the Antarctic atmospheric environment.In the second part of this paper,the pollution characteristics of typical persistent organic compounds in sediments and dissolved water in Jiulong River Estuary were studied.Water and sediment samples in Jiulong River Estuary were collected on January 19 and February 22,2019.The concentration distribution characteristics and composition differences of PAHs,OCPs and PCBs at different sites of the river basin were discussed,and the possible sources of pollutants were explored.On this basis,the concentrations and distribution of pollutants in different environmental media and the possible influencing factors were analyzed.The potential health risk of pollutants in water environment and the ecological risk caused by sediment were evaluated.The main conclusions were as follows:（1）The total concentrations of dissolved OCPs in surface water of Jiulong River ranged from 1.90 to 82.58 ng L-1(mean of 30.75 ng L-1).The total concentrations of 28 PCBs ranged from 0.71 to 61.46 ng L-1(mean of 17.99 ng L-1)whileΣPAHs ranged from 38.49 to 755.19 ng L-1.The average concentration in January was higher than that in February.Compared with the historical data of this basin,the concentration ofΣPAHs decreased year by year,but it was still at a high level compared with other estuary and basin at home and abroad.（2）In the sediment samples,the concentrations of total PAHs ranged from 10.09to 2388.46 ng g-1 at each sampling site in January,with an average concentration of688.85 ng g-1 and 268.13 to 823.20 ng g-1 in February,with an average concentration of 528.41 ng g-1.The average concentration of all stations in January was higher than that in February,and the concentration of all sampling stations showed a trend of higher in the upstream than in the downstream.The maximum concentration of PAHs was found at river confluence,and the concentration of PAHs at estuarine inlet decreased significantly.The concentrations of total PCBs were 1.18-12.25 ng g-1(mean of 6.15 ng g-1)in January and 2.60-11.07 ng g-1(mean of 5.21 ng g-1)in February in the sediments of each sampling site.The concentrations of all the OCPs in the sediments ranged from 0.80 to 31.23 ng g-1 in January(mean of 10.51 ng g-1),and from 2.09 to 17.46 ng g-1 in February(mean of 6.72 ng g-1).（3）The dissolved PCBs in Jiulong River were mainly substituted by hexamlor,followed by dichloro,trichloro and tetrachloro.The substituted PCBs in sediments were mainly substituted by tetrachloro,followed by pentachloro and tetrachloro.The OCPs in water bodies are mainly early residues,and endosulfan in sediments may have new contaminants.PAHs were mainly found in the second and third rings,followed by the fourth rings,and only a few stations were detected in the fifth ring and above rings.The main source of PAHs was combustion,especially the combustion of petroleum fossil fuels.The main sources of PAHs in sediments were coal and biomass combustion.（4）The concentration of pollutants in the Jiulong River estuary was negatively correlated with salinity and positively correlated with chlorophyll content.Compared with the historical data of this area,the concentration of pollutants has been decreasing year by year,but it is still at a higher level compared with other harbors.The water quality of this area,as far as OCPS is concerned,meets the national seawater quality standard,while the concentration of PCBs is far beyond the water environmental assessment standard of the United States.The overall ecological risk of each POPs in the sediments is low,only p,p’-DDT concentrations are high in the upstream of the estuary and the junction of Xixi and Nanxi,which may have a certain negative impact on aquatic organisms. |
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