污染场地总石油类馏分分段法风险评估

在对某汽车工业污染场地开展土壤与地下水环境调查的基础上,根据《污染场地风险评估技术导则》中的推荐模型,采用馏分分段法对总石油类进行风险评估研究。结果表明,1)该场地主要污染物为总石油类,土壤污染物中C12~C16脂肪烃的非致癌危害商在敏感用地和非敏感用地两种用地方式下均大于1,地下水污染物中C8~C10脂肪烃、C12~C16脂肪烃、C16~C21脂肪烃、C21~C34脂肪烃、C21~C35芳香烃的非致癌危害商在两种用地方式下均远大于1;2)敏感用地方式下,土壤中总石油类的修复限值为1 023.92mg/kg,地下水中总石油类的修复限值为1.805 mg/L;3)非敏感用地方式下,土壤中总石油类修复限值为3 292.92 mg/kg,地下水中总石油类的修复限值为11.457 mg/L。

Risk assessment for a polluted site based on total petroleum fractionation

The present paper attempts to introduce the heahh-risk assessment of the total petroleum based on the fraetionation by taking a car-making industry company in Hubei as a case study sample.As is well known,it is of great necessity to pay close attention to the health risk study for the polluted site located in any busy industrial city.It is just starting from this very need that,first of all,we have undertaken an environmental survey of the soil and groundwater impact on the automobile industry site,where the main production duty is to harden the heated steel plate into leaf-spring steel wares.What we have taken as a study sample is the polluted soil and contaminated groundwater samples through laboratory testing and investigation for the detailed pollution and contamination status-in-situ in accordance with the state environment-protection criteria.The results of our testing and investigation demonstrate that,the content concentration rate of the total petroleum pollution indexes of some soil samples proves to be far more serious than the second standard indexes of the living quarters and the commercial areas in accordance with the Environmental Quality Standards for Soils (GB 15618-2008),to be exact,896 g/L over the maximum indexes of the groundwater standard,which is far beyond the minimalist limit of the riskbased pollution-free levels for the total petroleum hydrocarbons of Oklahoma standard indexes (USA) for the clean pollution-free water standard.Furthermore,we have done the simulated tests for the pollution situation of the site by using a surfer software.The testing results of the samples prove that the pollution sources located in the area around the workshop known as SANDUNBAN and the contaminants over there spread faster in the current groundwater flowing direction.The main contaminant of the site is TPH according to the survey.The risk assessment results we have found can be stated in the following top-down order:aliphatics (TPH)C8-C10 ＞ C12-C16 aliphatics (TPH) ＞ C16-C21 aliphatics (TPH) ＞ C21-C34 aliphatics (TPH) and ＞ C21-C35 aromatics (TPH).And,in view of the fact that the total petroleum is a mixture of various hydrocarbons,which is the first time the five fractions of TPH distilled,should be analyzed,respectively.Furthermore,we have also analyzed the hazard extent,and assessed the exposure,the toxicological risk characteristics successively with the model recommended in the Technical Guidelines for hazards of the contaminated sites(HJ 25.3-2014).The results of our analysis reveal that,the non-carcinogen hazard quotients of ＞ C12-C16 aliphatics (TPH) of the soil turn out both greater than 1 in the sensitive and insensitive land-use mode,whereas the non-carcinogen hazard quotients can be stated in the following top-down order:＞ C8-C10 aliphatics (TPH),＞ C12 -C16 aliphatics (TPH),＞ C16-C21 aliphatics (TPH),＞ C21-C34 aliphatics (TPH),＞ C21-C35 aromatics (TPH) of groundwater,all of which are far greater than 1 in both landuse modes.And,eventually,the acceptable risk control goals of the aimed contaminants have been worked out with the control goals of TPH derived.The remediation goal of TPH for the soil on the sensitive land evaluated by using the use standard goals,is equal to 1 023.92 mg/kg and 1.805 mg/L for the groundwater.In contrast,in the insensitive land use mode,the remediation target of TPH for the soil should be 3 292.92 mg/kg with that of the groundwater being 11.457 mg/L.