长江口徐六泾颗粒态正构烷烃的月变化组成特征及来源解析

Monthly Changes of the Composition and the Source Apportionment of Particulate Organic Matter n-Alkanes in Xuliujing,Changjiang Estuary

2003年6月到2005年12月之间,在长江口徐六泾站位按月际采集表层水样用于颗粒态正构烷烃的测定。徐六泾颗粒态样品总正构烷烃含量在0.3~3.8μg·L-1范围内,高值多集中在每年4月到8月。正构烷烃的碳数范围在C15到C36之间,主峰碳主要为C27、C29和C31。徐六泾颗粒态正构烷烃分布可分陆源输入优势型、陆源和水生生物混合优势型及石油污染型等3种类型,其中陆源输入为主,少部分冬、春季样品的分析结果显示为陆源与水生生物共同作用类型,可能与低悬浮颗粒物浓度和海水倒灌的影响有关。UCM结果显示徐六泾石油烃污染主要分布范围为C28-C33,与推测的船只燃料油污染相吻合。

Particulate n-alkanes had been collected monthly in Xuliu]ing , Changjiang Estuary, from June 2003 to December 2005 for the measurement of alkanes. The concentrations of particulate total n alkanes varied from 0.3μg· L-1 to 3.8 μg· L-1, with the peak values often observed during April to August. The distribution of carbon numbers of n-alkanes is from C15 to C36, and the Cmax are C27, C29 and C31. The peak distribution patterns of particulate n-alkanes can be divided into three types： The typical terrigenous n--alkanes dominated by the mixture of terrigenous n-alkanes and aquatic n-alkanes, and the petroleum polluted pattern. In general, the terrestrial inputs were dominated in most samples. The mixture pattern observed in samples collected during winter and earlier spring may suggest the impact of low suspended particle and seawater intrusion. Results of UCM show that the petroleum hydrocarbon pollution in Xuliujing is mainly distributed from C^8 to C33 , which is consistent with the known vessel fuel oil.