天津地区表层土壤和河流沉积物中正构烷烃化合物的成因分析

GENETIC ANALYSIS OF NORMAL ALKANE CONTAMINANTS IN THE SURFACE SOILS AND FLUVIAL SEDIMENTS FROM TIANJIN REGION

对天津地区表层土和河流沉积物中正构烷烃化合物进行了测试分析。不同环境功能区正构烷烃组成特征存在一定差别。表层土和河流沉积物中正构烷烃主峰碳、CPI和轻重比指数等地球化学参数分析表明,样品中中、低碳数正构烷烃主要来源于石油及其衍生物,个别样品中C17、C19 正构烷烃含量很高,并具明显的奇碳优势,可能与藻类生物活动有关;高碳数正构烷烃具有比较明显的奇碳优势,主要来源于高等植物蜡质的降解产物。不同环境功能区污染源的构成也存在比较明显的差别。

Normal alkane compounds have been detected in surface soil and fluvial sediment samples from various environmental domains in Tianjin City, and the compositional and distributional characteristics of n-paraffin compounds extracted from surface soil and sediment samples in different domains are significantly different. The compositional and distributional characteristics and the pollution sources have been investigated in this paper. The results showed that the normal-alkanes with mid- to low molecular weight are mainly derived from crude oil and its products, with the exception of some samples in which the normal alkane compounds have a remarkable predominance of n-C (17) or/and n-C (19), which may be derived from degradation products of modern algae, according to the main carbon number, the distribution of carbon numbers, CPI and the ratio of low molecular weight normal alkane to high molecular weight normal alkane. The high molecular weight normal alkanes with a distinct predominance of odd number carbon normal alkane compounds to even number carbon normal alkane compounds are derived from the degradation products of waxy material of vascular plants. Pollution sources are distinctly different from one area to another with different environmental characteristics.