(1) 中国科学院烟台海岸带研究所

In the Yellow River Delta region,long-term exploitation of oil and gas in Shengli Oilfield has caused the deterioration of soil environmental quality in the oil production areas. Soil samples were collected from the oil-contaminated area of Shengli Oilfield. The distribution of 10 heavy metal elements (Pb,V,Cr,Mn,Fe,Co,Ni,Cu,Zn and Cd), soil particle size and total organic carbon (TOC) specific gravity under the influence of petroleum pollution were studied.The results showed that the soil particles d0.5 of 19 soil profiles ranged from 18 to 44 mum,most of which belonged to fine sand. The vertical distribution of heavy metals in the soil profiles of the oilfield contaminated area was significantly different from that of the non-polluted area. Affected by petroleum hydrocarbons and their degradation products,the eight major heavy metal (Pb,V,Mn, Fe,Co,Cu,Zn and Cd) in the 010 cm or 1020 cm layers of the oilfield has the highest. The maximum values are 32.51,88.04,336.9,2.530*10~4,9.76,23.46,87.15 and 0.38 mg·kg~(-1), respectively. The control group was influenced by the process of soil formation,and there were two different changes of heavy metals in the deep layers of soil (3050 cm). In addition,through cluster and correlation analysis,in the oilfield,the eight major heavy metals (Pb,V,Mn,Fe,Co, Cu,Zn and Cd) were mainly impacted by the leakage of petroleum in the shallow layers,but the deep layers were mainly affected by the soil background value. The correlation between heavy metal contents and TOC (removed the surface layer) is high. Cr and Ni were affected by the soil formation process. The eight heavy metals in the non-oil area were affected by the atmospheric deposition and soil formation. There is a general negative correlation between heavy metal content and clay,silt particles,but there is no obvious correlation between the content of heavy metals and TOC. Overall, the results show that the content,movement and distribution of heavy metals in the oilfield soil are influenced by oil pollution and oilfield development. This study will provide a scientific and theoretical basis for the prevention and control of heavy metals-petroleum hydrocarbon composite pollution in the Yellow River Delta wetland.