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

发布时间：2018-05-12 17:50

本文选题：潮间带 + 沉积物　；参考：《中国科学院烟台海岸带研究所》2017年硕士论文

【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(δ~(15)N)、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20.1~123.7μmol/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61.8~335.3μmol/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30.1~177.8μmol/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90.7~357.9μmol/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168.9~900.9μg/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177.6~1125μg/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δ~(15)N数值处于4.3‰~8.0‰之间,δ~(15)N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,δ~(15)N数值处于3.1‰~7.2‰之间,δ~(15)N数值的最高值和最低值分别出现在涧河河口和东寨港中。δ~(15)N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δ~(15)N数值均超过5‰,且δ~(15)N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δ~(15)N、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;径流量较小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。
[Abstract]:There is an outstanding problem of nitrogen pollution in the intertidal sediments of China. However, the research on the source of nitrogen pollution in the intertidal sediments, evaluation and even restoration is not complete. The nitrogen sources and concentration levels in the sediments of 11 intertidal zones in China are synthetically analyzed, and the nitrogen pollution in the sediment is taken directly and indirectly. At the same time, the intertidal zone in Shandong peninsula was selected as a typical research site. In view of the degradation of some bacteria and the characteristics of nitrogen pollutants, the diversity of the community structure of planktonic bacteria under different nitrogen pollution conditions was explored. The purpose was to find the more sensitive species of nitrogen contaminants in the later nitrogen pollution. The main research work and results are described as follows: (1) from 9 to November (dry season) in 2014 and 6 to August 2015 (wet season), samples were collected in the great Liao River Estuary, Jiaohe estuary, the Yellow River Estuary, Dagu estuary, the northern Jiangsu shoal, the Yangtze Estuary, the southern bank of the Hangzhou Bay, the Minjiang estuary, the Kowloon estuary, the Pearl River Estuary and the East Village port. The content of nitrogen nutrients in seawater and interstitial water, total nitrogen (TN), stable nitrogen isotope (delta ~ (15) N), carbon nitrogen ratio (C/N) and other parameters. The results showed that the total soluble nitrogen (TDN) concentration in the overlying sea water samples was between 20.1~123.7 and mol/L in dry season, and the highest and lowest value of TDN concentration appeared in the estuary of the great Liao River and North Jiangsu, respectively. In the wet season, the concentration of TDN is between 61.8~335.3 and mol/L, the maximum and minimum of TDN concentration appear in the Jiulong River Estuary and the northern Jiangsu shoal respectively. The TDN concentration in the interstitial water samples is relatively high; in the dry season, the TDN concentration in the interstitial water samples is between 30.1~177.8 u mol/L, and the highest and lowest TDN concentration in the Pearl River Estuary respectively. In the wet season, the concentration of TDN in the wet season is between 90.7~357.9 and mol/L, and the highest and lowest TDN concentration in the River Estuary and the East Village port respectively. In the dry season, the content of TN is between 168.9~900.9 and g/g, the highest value and the lowest value of TN content appear in the nine Longjiang and the Yellow River Estuary, respectively. The content of TN in the sediments is between 177.6~1125 and g/g, and the highest and lowest values of TN content appear in the River Estuary and the Yellow River Estuary respectively. (2) in the dry season, the delta ~ (15) N values are between 4.3 and ~8.0 per thousand, the highest value and the lowest value of the delta ~ (15) N value appear in the Jianhe estuary and Dong Zhai harbor respectively; in the wet season, the delta ~ (15) N number The maximum value and minimum value of the value of delta ~ (15) N value are in Jianhe estuary and Dong Zhai harbor respectively. Delta ~ (15) N values are in the Yellow River Estuary, North Jiangsu shoal and Dong Zhai harbor in the range of marine nitrate (3 per thousand ~5 per thousand), and the value of delta ~ (15) N at other stations is more than 5 per thousand, and the delta ~ (15) N value is in the estuary. The River Estuary and Dagu estuary were significantly higher than other stations, indicating that nitrogen input was greatly influenced by human activity. In the dry season, C/N was between 7.7~14.7 and in the wet season between 8.2~14.6, indicating that the organic matter in the sediments was a mixed.C/N ratio of marine and terrestrial organic matter in the Yangtze Estuary, the Minjiang mouth, and the Kowloon River Estuary. And the relatively high estuary of the Pearl River (12) indicates that the input of the land source is relatively large. However, C/N is relatively low in the Yellow River Estuary and the northern Jiangsu shoal, and is in the C/N range near the sea source organic matter (5~8). According to the nitrogen distribution in the different intertidal zones, the intertidal sediments are synthetically analyzed in combination with the delta ~ (15) N, C/N, geographical location and human activity data. The main source of nitrogen in intertidal sediment is the use of chemical fertilizer, culture, sewage discharge and river transportation. (3) the direct and indirect evaluation methods are used to evaluate the nitrogen pollution in intertidal sediments, overlying water and interstitial water respectively, and then reflect the precipitation in different intertidal zones. The results of the evaluation of nitrogen pollution in the sediments reveal that nitrogen pollution in the non estuarine sediments is relatively lighter than that in the estuarine area, and the level of nitrogen pollution in the estuarine area with the smaller runoff is higher than that in the estuarine area with large runoff, and the rainfall and river transport may transport a large amount of nitrogen material to the intertidal zone in the wet season. The degree of nitrogen pollution in the intertidal zone was relatively heavy. (4) in order to explore the diversity of bacterial community structure under different nitrogen pollution conditions, in July 2014, planktonic bacteria were carried out at seven sites in the maisan beach and mudflat area, the Sima river beach area, the the Yellow River Delta and the rice grass area, the Swan Lake seagrass area and the Yantai Bay Bay. Sample collection work. By extracting the total DNA of the sea water samples from the intertidal zone, the 16S rDNA clone library was constructed and the structure of the bacterial community was analyzed. The community similarity analysis (ANOSIM) and the non metric multidimensional scale conversion ranking (NMDS) were used to explore the diversity of the community structure of bacteria under different nitrogen pollution conditions. The structure of planktonic bacteria community in different intertidal zones has great influence, and the vegetation cover can change the structure of planktonic bacteria in the environment by absorbing nitrogen substances and releasing various types of organic matter. A large amount of organic nitrogen, such as organic nitrogen, makes the alternating monobacteria in gamma deformable bacteria become the dominant species in the beach area. It is of great significance to screening functional strains for biological nitrogen removal in the future.

【学位授予单位】：中国科学院烟台海岸带研究所
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X55;X172;Q938.8

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