加油站场地油品渗漏探测及土壤污染评估

Leak detection of underground storage tank and assessment of site contamination at gas stations

用洛阳铲采集某地区10座地下贮罐罐龄接近或超过10年的典型加油站场地不同深度土样,并分别用吹脱/捕集/热脱附/气相色谱法和快速溶剂萃取/硅酸镁净化/气相色谱法分析样品中的挥发性和萃取性石油烃,发现2座加油站疑似油品渗漏,其中1座为柴油渗漏,地下贮罐附近1.2～3.0 m深度土壤总石油烃含量16.1～24.6 g/kg,均超过荷兰土壤清除标准,另1座为汽油和柴油混合渗漏,其地下贮罐附近2.4 m深度土壤总石油烃含量较高,但未超标。个别加油站场地较高的土壤天然有机物背景值可能计入EPH的分析结果,但其色谱指纹明显不同于石油烃。

Different depth soil samples were collected using Luoyang shovel at ten gas station sites where underground storage tanks had served more than 10 years.Volatile petroleum hydrocarbons and extractable petroleum hydrocarbons in soil samples were analyzed by purge and trap/thermal desorption/gas chromatography and accelerated solvent extraction/florisil purification/gas chromatography,respectively.Two gas station sites were found with petroleum product leaks and soil contamination.One of them could have diesel leak,and the concentrations of total petroleum hydrocarbons ranged from 16.1 to 24.6 g/kg in 1.2 ～3.0 m of soil near the underground storage tanks,which exceeded intervention values for soil remediation in Dutch standards.Another one could be leaking gasoline and diesel simultaneously,and the highest concentration was found for total petroleum hydrocarbons in 2.4 m of soil,which was lower than intervention values for soil remediation in Dutch standards.In some gas station sites with higher concentration of natural organic matter,extractable petroleum hydrocarbons could partly derive from degradation products of natural organic matter,which is often different in the fingerprint of gas chromatogram from real petroleum hydrocarbons.