城市湖泊底泥沉积柱中正构烷烃的分布特征与来源解析  

Occurrence and Source Apportionment of Alkanes in the Sediment Core in an Urbanized Lake

作　　者：杨泽玉[1,2] 鲁倩 吴来燕[2] 孙杰[2] 杜冬云[2] 唐和清[2] 

机构地区：[1]中国地质大学生物地质与环境地质教育部重点实验室,湖北武汉430074 [2]国家教育部与国家民委催化材料重点实验室、湖北省催化材料协同创新中心、中南民族大学化学与材料科学学院,湖北武汉430074

出　　处：《环境科学与技术》2014年第6期115-119,147,共6页Environmental Science & Technology

基　　金：国家自然科学基金项目(41373133);中国地质大学生物地质与环境地质国家重点实验室开放课题(BGEGF200816);国家民委科研项目(12ZNZ003);中南民族大学自然科学基金项目(CZY13027)

摘　　要：正构烷烃既可以来自于生物质的排放，也可以来自于人类的活动（如各种化石类燃料的直接排放和不完全燃烧）。由于其具有较高的稳定性，对沉积物中有机物质来源和沉积物环境演化具有指示性，因此，正构烷烃在现代沉积物的研究中常作为主要的环境指示指标。该研究以武汉市南湖为城市湖泊的代表性湖泊，通过研究南湖底部沉积柱中正构烷烃的分布特征，不同沉积柱深度中总有机溶剂萃取量（TSEM）、正构烷烃总浓度、碳优势指数（CPI）值及一些诊断因子（如Pri/n—C17或Phy／n—C18）的变化趋势，对南湖底部沉积柱中有机质的主要来源进行了分析。研究结果表明，南湖底泥沉积柱（0～50cm深度）中均检出不同程度的正构烷烃，并呈现出明显的双峰型分布特征，其总浓度范围位于38．1—298g／g（干重）之间。其中正构烷烃及TSEM均随着沉积柱深度的增加而呈现出下降的趋势。CPI的分析表明，该湖泊中有机质主要来自于陆生植物蜡与人类活动的混合污染源，而且虽然南湖水体富营养化严重，但是沉积柱中的有机质已经经历了一定程度的微生物降解。该研究为控制与修复以南湖为代表的城市湖泊的水体污染提供了有力的理论基础。As one of the main components of anthropogenic and biogenic hydrocarbons, n-alkanes are commonly used as one of the sediment environment indicatives to study the evolution of organic matter in the sediment source due to their high stability. In the study, South Lake, which locates in an urbanized area of Wuhan, Hubei Province, was selected as the representatives of urbanized shallow lakes. The distribution profiles of n-alkanes ranged from n-C9 to n-C40 was investigated for a sediment core sampled from this seriously eutrophicated lake. Variation of total solvent extractable materials （TSEM）, total concentration of n-alkanes, carbon preference index （CPI） derived from different estimation criteria, as well as diagnostic ratios such as pristane/n-C17 and phytane/n-C18, with the depth of sediment core were compared and evaluated. Results showed that the identified n-alkanes in different sediment depth ranged from n-C9 to n-C4o, total concentration of n-alkanes ranged from 38.1 to 298 μg/g dry sample （dw）. Both TSEM and total concentration of n-alkanes decreased with the increase of the sediment depth. Occurrence and CPI analysis of n-alkanes at different sediment depths indicated that they were mainly derived from the mixed sources of anthropogenic and land plant wax with biodegradation indicators. This study is designed to provide valuable information to control water pollution for similar urbanized lakes.

关 键 词：城市湖泊 正构烷烃 沉积柱 分布特征 来源解析 

分 类 号：X832[环境科学与工程—环境工程]