兰州市典型湿地沉积物中正构烷烃的来源分析

Source Analysis of N-alkanes from Typical Wetlands Sediment in Lanzhou City,China

采用GC-MS联用系统对三个兰州市典型湿地的沉积物生物标志物——正构烷烃的组成进行了测定,分析了湿地沉积物中正构烷烃组成特征并探讨了其指示的污染源信息。研究结果表明,兰州市湿地沉积物中正构烷烃主要存在高碳数组分奇偶优势显著的单峰型和低碳、高碳组分都有奇偶优势的双峰型两种分布形式;CPI指数分析表明兰州市湿地沉积物中正构烷烃贡献的高碳数部分来源于湿地周围的高等陆生植物,而低碳数部分来源于化石燃料残余。此外,研究发现采石场湿地和银滩湿地公园污染源效应较统一,而雁滩公园污染源受频繁人为活动影响而显示出明显的多元性。

Using GC-MS analysis,n-alkanes composition characteristics and biomarker in sediments from three typical wetlands in Lanzhou City,China were studied. Results show that firstly,there are two main composition styles for n-alkanes from wetland sediments in Lanzhou City,which are unimodal shape with an OEP（ odd-even predominance） in high carbon n-alkanes and bimodal shape with OEP in both low and high carbon n-alkanes. Secondly,CPI proxies（ including CPI1 and CPI2） analysis suggests that high carbon n-alkanes is contributed from trees for landscape and low carbon n-alkanes is resulted of using fossil fuel. Lastly,it is found that Caishichang Wetland and Yintang Wetland Park suffer the similar effects by pollution source. But,the effects on pollution source of Yantang Park show different obviously and it may have a close relation with human activities.