Distribution Characteristic and Impact Assessment of Pb in the Soil Around the Gas Stations in Jiaxing City

Eleven typical soil samples around gas stations in Jiaxing city were selected and microwave extraction method with nitric acid,hydrochloric and acid-hydrofluoric acid digestion system was used to digest the soil samples.Atomic absorption spectrometry method was applied to determine lead content in the soil samples.Then method of single-factor pollution was adopted to evaluate lead contamination in the soil samples.The results show that the concentration of lead in the soil around the gas station in Jiaxing city ranges from 20.5 mg/kg to 40.6 mg/kg,the average concentration is 31.6 mg/kg.Taking the first class standard of national soil environmental quality standard as evaluation criteria,pollution index of Pb ranges from 0.59 to 1.16.All the conclusions reveal that the soil around the gas station is polluted at certain degrees.Afterwards,relationship between the Pb content in the soil and parameters of soil pH,SOM,number of the vehicle and years of the gas stations were analyzed in detail.Significant correlation between the Pb contents and vehicle number is discovered and the relationship coefficient is 0.88.Posterior relationship consists in the Pb contents and founded years of the gas stations,and the coefficient is 0.22.Whereas there are not any distinctive correlation consisted in Pb content and the other two parameters.