厦门近海沉积物中高分子有机质的来源初探

Primary research on origins of the macromolecular organic matters in offshore sediments in Xiamen

采用多步连续-湿法-化学方法,分离提纯了于2010年7月和12月在厦门近海采集的沉积物样品,获得3类高分子有机质,即腐殖酸(HA)、干酪根和碳黑(KB)和碳黑(BC)。以扫描电镜(SEM)作为有效的辅助手段,观察沉积物原样及高分子有机质的形貌特征,结合稳定碳同位素(δ13C)的分析,初步探讨了厦门近海沉积物中高分子有机质的来源。扫描电镜观察发现,在原样沉积物中存在多种海源物质(如钙质硅藻和圆筛藻/冠盘藻);而在KB样品中同时发现类似于陆地植物的木质碎片以及来自海洋的藻胶鞘,暗示了其来源是海源与陆源共同作用的结果。稳定碳同位素研究表明厦门湾近海海域沉积物中有机质以陆源影响占优势,其比例在58.32%至84.45%之间;δ13C值整体上显示为夏季的贫于冬季的,这与研究区域的生态系统中陆源C3植被和海源水生植物的繁殖生长有关,同时还有排海污水及化石燃料煤燃烧后或者运煤船只洒落的碎屑的贡献。

A promoted comprehensive-wet-chemical procedure was performed to extract three Macromolecular Organic Matters（MOMs）,including humic acid（HA）,kerogen and black carbon（KB） and black carbon（BC）,from marine sediments,which were collected in Xiamen Bay during July and December in 2010.The origins of three extractions were characterized by scanning electron microscopy（SEM） and stable carbon isotope（δ 13 C） analysis.The results of SEM showed that many of marine-derived materials were observed（eg： calcium diatoms,and coscinodiscus or stephanodiscus hantzschii）.Wood debris and algaenan that origined from marine were discovered in KB samples,which indicated that the importance of the multiple sources.The δ 13 C analysis shown that the terrestrial contribution ranged from 58.32%~84.45%,which was the predominant contribution to the MOMs in the sediments.And the δ 13 C values in summer were lower than that in winter,which was connected with the contribution of C3 plants and aquatic plants in the ecosystem.In addition,the discharge of sewage,coal combustion and coal debris floating down from shipping were also the reasons to lead this phenomenon.