中国典型湖泊沉积物中脂肪烃的分布特征及来源

Distribution Characteristics and Origins of Aliphatic Hydrocarbons in Sediments from Typical Lakes in China

以我国13个典型湖泊的表层沉积物为研究对象,对沉积物的w(TOC)和w(TN)的分布特征进行了报道.结果显示,西南、华南地区湖泊沉积物的w(TOC)和w(TN)要高于西北地区,华东地区湖泊沉积物最低.结合多个脂肪烃来源参数,初步探讨了13个典型湖泊表层沉积物中脂肪烃的分布特征及来源.结果表明:湛江玛珥湖、四海龙湾、洱海、红枫湖和程海受脂肪烃污染严重,鄱阳湖和双塔水库受脂肪烃污染程度最轻;受水体高矿化度的影响,双塔水库沉积物中有机质的δ13C值明显偏正;湛江玛珥湖中来自自身固氮藻类的脂肪烃含量明显高,致使湛江玛珥湖沉积物的δ15N值明显低;由于四海龙湾特殊的地理环境,四海龙湾沉积物中来自陆源木本植物的w(C27+C29)明显高.

The surface sediments from thirteen typical lakes in China were investigated,and the distribution characteristics of the contents of TOC and TN are presented.The contents of TOC and TN in lake sediments from southwest and southern areas of China are higher than those from northwest areas.The lowest content values are in lake sediments from eastern areas.Combining a few hydrocarbon origin parameters,the distribution features and sources of hydrocarbons in surface sediments from the thirteen typical lakes are discussed.The results show that Zhanjiang Maar Lake,Sihailongwan Lake,Erhai Lake,Hongfeng Lake and Chenghai Lake have been heavily polluted by hydrocarbons.Poyang Lake and Shuangta Reservoir have the lightest polluted water.Because of the influence of high degree of mineralization,the δ13 C value of organic matter in the surface sediment from Shuangta reservoir is evidently partial positive.The content of hydrocarbons from nitrogen-fixing algae is apparently higher,resulting in lower δ15 N value in the sediment from Zhanjiang Maar Lake.Because of special geographical environment,the content of（C27 ＋ C29） tree-derived is apparently higher in the Sihailongwan Lake sediment.