我国典型潮间带沉积物中氮污染状况及浮游细菌群落对氮污染的响应

	我国典型潮间带沉积物中氮污染状况及浮游细菌群落对氮污染的响应
	王恩辉1,2
学位类型	硕士
导师	刘东艳 ; 李桂生
	2017-05-18
学位授予单位	中国科学院大学
学位授予地点	北京
关键词	潮间带沉积物氮污染浮游细菌
其他摘要	我国潮间带沉积物中存在突出的氮污染问题。然而，关于潮间带沉积物中氮污染来源、评价乃至修复的研究尚不完备。本研究对我国 11 个潮间带沉积物中的氮素来源与浓度水平进行了综合分析，并采取直接和间接的方式对沉积物氮污染状况进行评价。同时，选取山东半岛潮间带作为典型的研究地点，针对部分细菌具有降解、利用氮素污染物的特征，探索了不同氮污染条件下浮游细菌的群落结构差异，旨在发现对氮素污染物响应较为灵敏的菌种用于后期氮污染的生物治理。主要研究工作与成果表述如下：（1）于 2014 年 9 至 11 月（干季）和 2015 年 6 至 8 月（湿季），分别在大辽河口、涧河河口、黄河口、大沽河口、苏北浅滩、长江口、杭州湾南岸、闽江口、九龙江口、珠江口、东寨港进行样品的采集工作，测定了各潮间带上覆海水及间隙水中氮素营养盐的含量、沉积物中总氮（TN）、稳定氮同位素（δ¹⁵N）、碳氮比（C/N）等参数。分析结果表明：在干季，上覆海水样品中总可溶性氮（TDN）浓度介于 20.1~123.7 µmol/L 之间， TDN 浓度的最高值和最低值分别出现在大辽河口和苏北浅滩；在湿季， TDN 浓度介于 61.8~335.3 µmol/L 之间， TDN 浓度的最高值和最低值分别出现在九龙江口和苏北浅滩中。间隙水样品中 TDN 浓度相对较高；在干季，间隙水样品中 TDN 浓度处于 30.1~177.8 µmol/L 之间， TDN 浓度的最高值和最低值分别出现在珠江口和长江口中；在湿季，间隙水样品中 TDN浓度处于 90.7~357.9 µmol/L 之间， TDN 浓度的最高值和最低值分别出现在涧河河口和东寨港中。在干季，沉积物中 TN 的含量处于 168.9~900.9 μg/g 之间， TN含量的最高值和最低值分别出现在九龙江和黄河口中；在湿季，沉积物中 TN 的含量处于 177.6~1125 μg/g 之间， TN 含量的最高值和最低值分别出现在涧河河口和黄河口中。（2）在干季，沉积物中 δ¹⁵N 数值处于 4.3‰~8.0‰之间， δ¹⁵N 数值的最高值和最低值分别出现在涧河河口和东寨港中；在湿季， δ¹⁵N 数值处于 3.1‰~7.2‰之间， δ¹⁵N 数值的最高值和最低值分别出现在涧河河口和东寨港中。 δ¹⁵N 数值在黄河口、苏北浅滩以及东寨港中基本处于海源硝酸盐的范围中（3‰~5‰），而在其它站位 δ¹⁵N 数值均超过 5‰，且 δ¹⁵N 数值在大辽河口、涧河河口以及大沽河口中显著高于其它站位，表明氮素输入受人类活动的影响较大。在干季，沉积物中 C/N 处于 7.7~14.7 之间，而在湿季处于 8.2~14.6 之间，说明沉积物中的有机质是海洋和陆源有机物的混合。 C/N 比值在长江口、闽江口、九龙江口以及珠江口相对较高（>12），表明陆源输入较大。然而， C/N 在黄河口和苏北浅滩中的相对较低，且在干季接近海源有机质的 C/N 范围之中（5~8）。根据不同潮间带的氮素分布状况，结合 δ¹⁵N、 C/N、地理位置以及人类活动数据综合分析潮间带沉积物中氮素来源状况，发现化肥的使用、养殖、污水排放以及河流运输等是潮间带沉积物中氮素的主要来源。（3）采用直接和间接的评价方式分别对潮间带沉积物、上覆水及间隙水中的氮污染状况进行评估，进而全面的反映不同潮间带地区沉积物中氮污染状况。评价结果共同揭示了非河口区沉积物中氮污染程度比河口区氮污染程度相对较轻；径流量的河口地区比径流量大的河口地区沉积物中氮污染程度高；降雨及河流运输可能在湿季输送大量的氮素物质到潮间带地区使潮间带地区氮污染程度相对较重。（4）为探究不同氮污染条件下细菌群落结构的差异性，于 2014 年 7 月在养马岛石滩与泥滩区、辛安河沙滩区、黄河三角洲碱蓬与米草区、天鹅湖海草区以及烟台月亮湾近海七个地点开展了浮游细菌的样品采集工作。通过提取潮间带海水样品的总 DNA，构建 16S rDNA 克隆文库，分析细菌群落结构组成；并利用群落相似性分析（ANOSIM）和非度量多维尺度转换排序（NMDS）探究不同氮污染条件下细菌的群落结构差异。发现氮素物质的含量及多样化对不同潮间带地区浮游细菌群落结构具有较大影响，且植被覆盖能通过吸收氮素物质、释放多种类型有机质的方式使环境中的浮游细菌群里结构发生变化。养马岛石滩区由于污水排放等因素造成的水体富营养化对浮游细菌结构产生了较大的影响，大量的有机氮等物质致使 γ-变形菌中的交替单胞菌科细菌成为石滩区的优势菌种，其对今后筛选功能菌株用于生物除氮的工作具有重要意义。 ; There is prominent nitrogen pollution in the intertidal sedments of China. However, the studies about sources identification, pollution assessment and repairation were not complete. In this study, among 11 intertidal zones, we used muti-biogeochemical parameters to analyze nitrogen sources and contents in sediments. At the same time, taking direct and indirect ways to evaluate the status of nitrogen pollution in sediments. Due to the ability of nitrogen degradation, making Shandong Peninsula as typical study areas, investigating the differences of bacterioplankton community from different nitrogen pollution conditions. The main work and results are as follows: (1) Two fieldtrips were arranged in 2014 and 2015, following the dry season (September to December, 2014) and wet season (June to August, 2015), respectively. Eleven sites were chosen for sampling, they distributed in the Daliao Estuary, Jianhe Estuary, Yellow River Estuary, Dagu Estuary, Subei Shoal, Yangtze River Estuary, Hangzhou Bay, Minjiang Estuary, Jiulong Estuary, Pearl River Estuary and Dongzhai Bay. At each site, surface sediments, pore-water and overlying seawater samples were collected for chemical analysis. In dry season, TDN concentrations in overlying seawater samples were between 20.1~123.7 µmol/L. The highest and lowest values appeared in Daliao Estuary and Subei Shoal, respectively. In wet season, TDN concentrations were between 61.8~335.3 µmol/L. The highest and lowest values appeared in Jiulong Estuary and Subei Shoal, respectively. In dry season, TDN concentrations in pore-water samples were between 30.1~177.8 µmol/L. The highest and lowest values appeared in Pearl River and Yangtze River Estuary, respectively. In wet season, TDN concentrations were between 90.7~357.9 µmol/L. The highest and lowest values appeared in Jianhe Estuary and Dongzhai Bay, respectively. In dry season, TN contents in sediments were between 168.9~900.9 μg/g. The highest and lowest values appeared in Jiulong Estuary and Yellow River Estuary, respectively. In wet season, TN contents were between 177.6~1125 μg/g. The highest and lowest values appeared in Jianhe Estuary and Yellow River Estuary, respectively. (2) In dry season, δ¹⁵N varied from 4.3‰ to 8.0‰. The highest and lowest values appeared in Jianhe Estuary and Dongzhai Bay, respectively. In wet season, δ¹⁵N values from 3.1‰~7.2‰. The highest and lowest values appeared in Jianhe Estuary and Yellow River Estuary, respectively. δ¹⁵N values in Yellow River Estuary, Subei Shoal, and Dongzhai Bay were almost in range of marine nitrate. However, δ¹⁵N values in other sites were exceed 5‰. δ¹⁵N values in Daliao Estuary, Jianhe Estuary, and Dagu Estuary were significantly higher than those in other sites, these suggested exogenous nitrogen input did exit in the intertidal zones. C/N ratios varied from 7.7~14.7 in dry season and 8.2~14.6 in wet season. C/N ratios in almost all of sites were between 10~15, which suggested organic matters in sediments were a mixture of marine and terrestrial organic matters. It’s remarkable that C/N ratios in Yangtze River Estuary, Minjiang Estuary, Jiulong Estuary, and Pearl River Estuary were relative high (>12). However, C/N ratios in Yellow River Estuary and Subei Shoal were significantly low and close to the marine range (5~8). In order to comprehensively understand nitrogen sources, we analyzed δ¹⁵N and C/N ratios combined with the nutrients data, geographical position and human acivities in different sampling sites. The results showed fertilizers, aquaculture, wastewater discharge and river transportation were main nitrogen sources in the intertidal sediments. (3)We evaluate the conditions of nitrogen pollution in seawater, porewater and sediments. Compared to non-estuarine areas, nitrogen pollution were more heavily in estuaries. Nitrogen pollution in estuaries with little runoff were more heavily than that in the estuaries with large runoff. Rainfall and river transportation may transport lots of nitrogen contaminants to the intertidal zones during the wet season. (4) In order to know the response of bacterioplankton community to nitrogen pollution, bacterioplankton samples from different intertidal zones were collected in July, 2014. The sampling sites were distributed in rocky, sandy and muddy flat of Yantai, wetlands inhabited by Suaeda and Sparina in the Yellow River Estuary, wetlands with seagrass in Swan Lake, respectively. Constructing 16S rDNA clone libraries to study the community structure and diversity of bacterioplankton. Non-metric multidimensional scaling (NMDS) and analysis of similarity (ANOSIM) were conducted to know the differences of community structure. The contents and diversity of nitrogen has a great influence in bacteriophankton communities, vegetation coverage can also affect bacteriophankton communities by absorbing nitrogen and releasing various types of organic matters. Remarkably, due to the sewage discharge and eutrophication in seawater, Alteromonas become the dominant bacteria in the rocky areas, which was important to finding functional bacteria for nitrogen removal.
文献类型	学位论文
条目标识符	http://ir.yic.ac.cn/handle/133337/21991
专题	中国科学院烟台海岸带研究所知识产出_学位论文
作者单位	1.中国科学院烟台海岸带研究所 2.中国科学院大学
第一作者单位	中国科学院烟台海岸带研究所
推荐引用方式 GB/T 7714	王恩辉. 我国典型潮间带沉积物中氮污染状况及浮游细菌群落对氮污染的响应[D]. 北京. 中国科学院大学,2017.

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