Concentration Characteristics,Source Analysis And Risk Assessment Of Polycyclic Aromatic Hydrocarbon(PAHs) Concentration In Surface Soil Of Anqing Downtown And Surrounding Areas

From may to July in 2019 in anqing city and the surrounding counties and cities area?in Huaining county,Anqing city,Tongling region,Chizhou region?of the communist party of China acquisition 85 surface soil?mainly based on farmland soil?,on the content of polycyclic aromatic hydrocarbons in the soil,distribution characteristics and potential sources are analyzed,at the same time the environment ecological risk is assessed.In this paper,soil samples were extracted by accelerated solvent extraction method,and purified by silica gel alumina column?filled with 2 cm anhydrous sodium sulfate,1 cm copper powder,10 cm silica gel,5 cm alumina,2 cm anhydrous sodium sulfate,and sebaceous cotton?,and 16 PAHs in soil were detected and analyzed by GC/MS.Use ratio method and principal component analysis?PCA?to research the sources of PAHs using benzene and at the same time?a?pyrene toxicity equivalent concentration,risk quality standard method of ecological risk assessment of PAHs in soil on the surface,and reference for our country"the soil environment quality standard"?GB 15618-2008?and Canadian soil environmental quality standard for cancer risk assessment.The main research conclusions are as follows:?1?All 16 PAHs were detected in the soil in this study area,and the concentration range of sigma PAHs was relatively low,ranging from 44.73 to 1990.32?g·kg^-1?dry weight,the same below?,with an average concentration of 419.23?g·kg^-1±25.4?g·kg^-1.The average concentrations of Anqing city,Huaining,Tongling and Chizhou were 309.5?g·kg^-1,178.9?g·kg^-1,199.6?g·kg^-1and 191.7?g·kg^-1,respectively.?2?Refer to Msliszewska^Kordybach's 16 grading methods for optimal control of PAHs pollution in soil:uncontaminated soil(?PAHs<200?g·kg^-1),mildly contaminated soil(200?g·kg^-1??PAHs<600?g·kg^-1),contaminated soil(600?g·kg^-1??PAHs<1000?g·kg^-1),and heavily contaminated soil(sigma PAHs>1000?g·kg^-1).Among the 25 soil samples in anqing city,18 samples of?PAHs?200 PAHs?g·kg^-11 and 5 samples of 600?g·kg^-1??PAHs<1000?g·kg^-11 and 2 samples of>1000?g·kg^-1.The soil in the sample area of anqing city has been contaminated,and most of the samples belong to uncontaminated soil.There are 20 soil samples in Huaining county,15 samples with PAHs<200?g·kg^-1and 3 samples with?PAHs<600?g·kg^-1,3 samples with?PAHs<1000?g·kg^-1.Most of the samples in this area are in the level of no slight pollution and the overall level is low.In the Tongling sample area,16 samples were located with PAHs?200?g·kg^-1,and the rest were all located with200?g·kg^-1??PAHs<600?g·kg^-1.The whole area was in the uncontaminated area.The sample points of Chizhou area with?PAHs?200?g·kg^-11 belong to uncontaminated soil,but the average concentration reaches 191.7?g·kg^-1,which is close to light pollution.?3?This study area ratio method analysis of soil PAHs sources mainly for the oil source and the combustion source,through further source analysis,principal component analysis?PCA?principal component factor of 1,2,3,said PAHs in soil derived from 3⁵ ring PAHs,has been identified as the combustion source,mainly from material?wood,etc.?the incomplete combustion of coal and coking industry and industry of coal,biomass burning,etc;Principal component factors 1,2 and 3accounted for 54.405%of the total contribution rate.Principal component factor 4reflects the traffic pollution source,accounting for 9.039%;Principal component factor 5 is the oil source,accounting for 8.103%of the total contribution.The results show that the main sources of PAHs in surface soil of anqing city and some surrounding counties and cities are petroleum and combustion sources,among which biomass fuel combustion and petrochemical combustion play a dominant role.?4?The method of toxic equivalent concentration of Benzo?a?pyrene was used to evaluate the ecological risk of soil PAHs in this study area.The results showed that it was roughly below the target reference value(33.0?g·kg^-1),and higher than the target reference value in some areas,and there were certain ecological risks.12,13toxicity equivalent sampling point is higher,after positioning found its located in anqing city zone,and the site is home to plant,and located in anqing city zone near my yue square,the sample area is the main economic activity and anqing city,the area around the foot traffic,traffic flow is big,serious pollution to the environment than other place.According to the positioning,the sampling points 31 and 32 are located near the national highway G206,which leads from anqing city to Huaining county.G206 is an important trunk road from anqing city to the surrounding counties and cities.The traffic of vehicles around it is more frequent than other points.Therefore,environmental risks already exist in anqing city and some surrounding counties and cities.These research areas pay more attention to environmental protection and adopt more effective measures to prevent and control environmental pollution.The ecological risk of soil samples in anqing and surrounding areas was evaluated by risk quality standard method.The results showed that the PAHs in 85topsoil samples collected from all samples did not exceed the median ecological risk effect?ERM?,indicating that the probability of negative ecological effects in the sample area was less than 50%.InP and BbF were detected in 85 samples,and the detection rates of BkF and BghiP were 97.98%and 95.71%respectively,indicating the possibility of negative ecological effects.In general,the surface soil in and around anqing city has a low probability of negative ecological effects,but InP,BbF,BkF and BghiP may cause negative ecological effects.When analyzing the risk of cancer,found in this study 7 kinds of carcinogenic polycyclic aromatic hydrocarbons?benzo[a]anthracene,benzo[a]pyrene and benzo[b]fluoranthene,benzo[k]fluoranthene and diphenyl?a,h?anthracene,indene[l,2,3-cd]and pyrene,chrysene?content in the range of 5.25⁹83.14 mu g·kg 1,with a mean of 218.33?g·kg^-1.It accounts for 10.16%⁵4.91%of the total PAHs,with an average of 33.54%.The TEQBaP of the 16 PAHs was 1.641?g·kg^-1371.532MB·kg-1,with an average of 47.489?g·kg^-1.The TEQ_BaPaP of the 7 carcinogenic PAHs was 5.205³49.083?g·kg^-1,with an average of 89.698?g·kg^-1,accounting for 56.800⁶9.813%of the TEQ_BaPaP of the 16 PAHs,indicating that the 7 carcinogenic PAHs were the main contributors to the TEQ_BaPaP of the 16 PAHs.However,Bap and DaA account for 29.364%and 55.365%of 16 PAHs TEQ_Bap,respectively,and have a large contribution to toxic equivalent concentration,which will be the focus of attention.According to the content of Bap and DaA stipulated in the soil environmental quality standards of China and Canada,the sample sites of Bap and DaA have individual points exceeding the standard.Although the excessive content is not very large,it will cause some potential risks to the health of human activities in the area.All in all,the potential carcinogenic risk caused by PAHs in the surface soil of anqing and surrounding areas is small,and individual points may generate potential risks.?5?In 85 soil samples,59.89%of Ant,52.79%of BbF BghiP 45.87%,36.29%of the BkF,39.47%of the BaP,Chry 37.11%,32.91%of BaA,19.23%of the Phe,16.78%Acy,13.61%of Flo and DaA,9.29%of Flo,Pyr and InP,Nap,7.19%5.01%of the Ace,less than 1 value,belongs to clean soil,clean,well protection commonly can.Of all the soil samples,the soil was the most clean.Of the 85 soil samples,Ace of 94.14%,92.63%of the Flu,Pyr and InP,87.96%of Flo,88.67%of the Nap and Acy,89.78%of the Phe,76.91%of the DaA,72.11%of BaA,66.31%of the BaP,Chry of 66.82%,63.01%of the BkF BghiP,57.94%,35.61%48.29%of BbF,Ant is higher than 1,less than or equal to 2 standard,indicates the general pollution harm,for the"clean"yet soil,If any pollutants enter the soil,we should be vigilant,pay attention to the investigation of the specific sources of pollutants in a timely manner,carefully protect the soil and prevent the pollution from getting worse.Overall,Anqing and surrounding areas of soil PAHs content is basic in a clean and is clean soil,falls within the scope of free from contamination or general pollution,completes the prevention,the minority of individual polycyclic aromatic hydrocarbons content is more than secondary standard,belongs to the light pollution,the risk of potential hazards should be more in-depth investigation.