In order to solve the problems in oilfield soil pollutants scoring and ranking, the indicator of persistence in the Chemical Scoring and Ranking Assessment Model (SCRAM) was modified by using cluster analysis. 60 typical pollutants in oilfield were divided into 4 categories by cluster analysis according to the values of their half-live in the first step, and then into 10 grades according to the distribution proportions in soil,and as a result a new scoring method that pollutants disperse across [0.5,5] with the interval of 0.5 was achieved. The method modified was then applied in oilfield soil pollutants scoring and ranking. The unproved method represents the impact the character of persistence has on overall scoring and ranking,thus changes the former situation that the persistence of 22 pollutants were treated as the same without considering different medium. Meanwhile, since the persistence characters of those pollutants are newly defined, the selecting among the sub-indicators of pollutants toxicity is also justified. And consequently the modified method leads to a more reasonable scoring and ranking output for the soil pollutants in the oilfield.%针对化学品评分排序模式(SCRAM)中持久性指标在某石油开采场地土壤污染物评分排序过程中存在的问题,选择研究场地60种典型污染物,使用聚类分析按半衰期值大小将其分为4类,然后依照各污染物在土壤中的分布比例再进行聚类分析得到10个等级,得到污染物在[0.5,5]内以0.5为间隔的新评分方法.通过上述方法对SCRAM模式中环境持久性指标进行修正,并将修正后的评分方法应用于某石油开采场地典型土壤污染物的评分排序中.经修正的评分方法体现了污染物在土壤中的持久性对其综合得分和排序的影响,改变了原模式下不针对介质将22种污染物的持久性特征一概而论的状况,同时,由于对这些污染物在土壤中持久性的重新定义,修正后的评分方法也纠正了污染物在毒性指标中亚分类(急/慢性毒性)选取的不合理性,使得评分排序结果更加全面可靠.
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