原油中的正构烷烃类在海沙和海水中风化的模拟实验

Weathering simulated experiment of n-alkanes of crude oil spilled in seawater and sand

通过自然条件下沙表层和水面溢油的模拟风化实验,采用GC-MS作为检测器,研究原油中的正构烷烃在厦门地区的风化规律.结果表明,在一个月的风化模拟实验中,两种不同介质溢油风化均明显体现轻组分的正构烷烃丢失现象,且正构烷烃组分在水面溢油的风化速率低于沙表层溢油速率1～2个碳数.沙上模拟实验后期APr/APh比值明显受到风化影响,诊断比值不适用于油源鉴别.诊断比值An-C17/APr、An-C18/APh在短期风化过程中受风化影响小.水面溢油模拟实验结束后发现水体中n-C13-n-C29的正构烷烃组分含量升高2.9%～327.4%.

According to the specifications for the identification system of spilled oil on the sea（GB/T 21247-2007）,the light weathering pattern of n-alkanes of crude oil spills was investigated using GC-MS in seawater and sand simulated weathering experiment.The results showed that the low molecular weight n-alkanes were lost,and the weathering ratio of n-alkanes in seawater simulated weathering was lower than in sand.The n-C9,n-C10,n-C11 and n-C12 disappeared in two weeks in the sand simulated weathering experiment,but in the sea water simulated weathering experiment,only n-C9 and n-C10 disappeared.The diagnostic ratios of An-C17/APr and An-C18/APh were relatively stable during the simulated weathering experiment,so they can be used for the oil sources identification in Xiamen area.The diagnostic ratio of APr/APh cannot be used for the identification of oil sources because in the later period of the one-month sand simulated weathering,the ratio changed significantly.The concentration of n-C13-n-C29 in seawater increased at the end of seawater simulated weathering experiment by 2.9%~327.4%.