长江口柱状沉积物中磷的存在形态及其分布特征研究

对长江口的柱状沉积物进行了总磷测定,并运用SEDEX方法分析了长江口柱状沉积物中5种形态磷的含量和分布。研究结果表明,柱状样沉积物不同站位各种形态磷的垂直分布各不相同,由表至底呈现多种分布状态,与沉积环境、沉积后的成岩作用有关。长江口柱状样沉积物有机磷的降解速率常数变化结果表明,长江口海域有机磷的降解主要发生在沉积物表层和次表层。2个柱状样沉积物中氮磷比远低于16∶1,说明长江口近岸海域沉积物中的磷主要来自陆源。对柱状样的年代分析表明,总磷含量随年代的变化有明显的区域特征性,长江口总磷含量的髙值与长江较大输沙量的年份具有一致性。浙江省环保科研计划项目(2008-30

The research on nutrients release during the decomposition of Chaetomorpha sp.

通过室内模拟,研究了不同环境条件下绿潮硬毛藻的分解速率,以及死亡藻体内营养盐的释放规律,以阐明硬毛藻大量衰亡对天鹅湖水质的潜在影响。结果显示,温度对硬毛藻分解速率的影响显著(P沉积物>营养盐水平;N释放为:沉积物>温度>营养盐水平。高温条件下,死亡藻..

Study on sedimentary characteristics and its effects on the formation and decomposition of gas hydrate on continental slope of the northern South China Sea

南海是中国最大的边缘海，覆盖着巨厚的富含有机质的沉积地层，沉积速率高，具备良好的生油生烃能力，具有巨大的资源潜力，是我国的海洋油气资源宝库。天然气水合物作为分布广储量大且对环境友好的资源，具有极高的科学意义和社会意义，南海北部陆坡是我国天然气水合物赋存的最有利海域。近年来南海北部多处天然气水合物钻探采样为我国天然气水合物资源的研究提供了强有力的支撑。本文通过对南海北部陆坡台西南盆地邻近海域地质调查所获沉积物柱状样进行粒度、有机碳、孔隙水、元素矿物等地球化学分析，以研究南海北部陆坡沉积物的分布特征及变化规律，并对比天然气水合物赋存区的沉积环境特征，探讨研究区域沉积物特征对天然气水合物形成、分解的...The South China Sea is the largest marginal sea of China, covered with thick sedimentary strata rich in organic matter, with high deposition rate, it is a good source of hydrocarbon generation ability, which has a great resource potential, it is a precious ocean oil and gas resource of China. As a widely distributed,large reserved and friendly to the environment resources, gas hydrate has importa...学位：理学硕士院系专业：海洋与环境学院_海洋地质学号：2242010115131

Different forms of nitrogen contents and their vertical variations of transformation modes of the sediments of Lake Yuehu, Wuhan

Vertical distributions of nitrogen contents, net nitrification rates, net N-mineralization rates and nitrate reductase activities in sediments of Lake Yuehu in June, 2005, were described on basis of four samples from the lake. The results showed that there was a critical layer in which exchangeable nitrate contents were the highest. Exchangeable ammonium and available nitrogen contents were the lowest in the Subsurface sediment (5-10cm). Available nitrogen was stored mainly in the form of exchangeable ammonium in both surface (0-5cm deep) and deeper layers (>10cm deep) where their contents were higher. The pattern of this distribution can be explained by anaerobic conditions. The surface sediment not only showed higher contents of total nitrogen and organic nitrogen, rates of net nitrification, N-mineralization and nitrate reductase activities, but also displayed the highest ammonium and the lowest nitrate concentrations in interstitial water. Therefore, based on a nitrogen cycling mode, we proposed that organic nitrogen was re-mineralized to ammonium and nitrate with processes of the former being nitrified into the later, resulting in anaerobic conditions that contributed to ammonium accumulation by the production of its own and nitrate reduction in interstitial water of surface sediment. In general, the surface sediment in eutrophic lakes, enriched by organic nitrogen, is the most active dimension for the biogeochemical cycling of nitrogen with ammonium being the major and most effective forms

Effect of root exudate on behavirors of polycyclic aromatic hydrocarbons (PAHs) in mangrove sediments

红树林是生长在热带、亚热带海岸潮间带的木本植物群落，对维护河口、海滨生态平衡和保护环境等方面具有重要意义。近年来，大量污染物被排放到红树林湿地生态系统中，其中以多环芳烃（Polycyclicaromatichydrocarbons，PAHs）为代表的有机污染物最为明显。由于PAHs具有较强的致癌、致畸、致突变作用，使其极易在沉积物中被吸附固定，研究根系分泌物对沉积物中PAHs的活化作用，植物修复PAHs的根际响应机制及其在根际微环境中的降解机理，将为深入探讨PAHs在根际沉积物中的生物有效性、评价其污染风险、提高修复效率等提供理论依据。 本文从沉积物中PAHs的吸附、解吸和有效性等方面，研究...Mangrove wetlands, represent a complex ecological habitat distributed in the tropical and subtropical coasts. As one of the most important wetland ecosystems, they have high productivity and possess precious natural resources, and appear to possess a significant capacity to retain organic contaminants. This is especially so for the polycyclic aromatic hydrocarbons (PAHs). PAHs have been reported w...学位：理学博士院系专业：环境与生态学院_生态学学号：3312012015356

Development of Simultaneous Determination Method for Multi-categorized Organic Pollutants in Sediment and Its Application to the Study of Combined Pollution Characteristics of the Jiulong RiverEstuary

我国沿海社会经济相对发达，河口区域承接着流域各类生产、生活活动排放的大量有机污染物。沉积物作为水环境的重要组成部分，既是污染物的主要归宿，又是污染物迁移的载体和二次污染来源。河口沉积物中频繁检出的多环芳烃（PAHs）、多氯联苯（PCBs）、多溴联苯醚（PBDEs）、农药和抗生素等有机污染物严重威胁着河口生态环境。本论文以PAHs、PCBs、PBDEs、农药和抗生素5类122种有机污染物为目标物，运用色谱-串联质谱技术建立了其在沉积物中的分组同时分析方法，并且应用于福建九龙江河口表层和柱状沉积物样品的分析，对污染物进行了污染特征、来源解析和初步生态风险评价研究。 主要研究内容和结果如下： 1...Over the past decades, with the rapid economic development in chinese coastal area, thousands of industrial, agricultural and domestic chemical pollutants are being imported into aquatic environment through direct use, atmospheric deposition, riverine runoff etc.. Sediments, acting both as a pollutant reservoir and as a potential secondary pollution source, are very important to water quality and ...学位：理学硕士院系专业：环境与生态学院_环境科学学号：2262011115144

九龙江流域地表水锰的污染来源和迁移转化机制

锰是人体必需微量元素,但近年来河流湖库等地表水锰超标现象时有发生,威胁供水安全.本文于2016—2017年在福建省九龙江流域开展水系沿程梯度调查及机理实验,结合历史监测资料综合研究,探明九龙江锰含量的时空分布与迁移转化规律,揭示九龙江锰的污染来源、超标成因与调控机制.结果表明,溶解锰高值及超标站位集中在北溪上游矿区支流和干流部分水库,且主要发生在枯水期;上游矿区支流颗粒锰含量最高,随后从上游到下游沿程递减,且与总悬浮颗粒物(TSM)和pH显著正相关(p7.8)环境促进亚热带红壤颗粒富集锰,大量富锰颗粒进入pH逐渐下降的河流下游和电站库区后向溶解锰转化,从而导致锰超标.河流下游及库区pH值下降的主要原因包括酸沉降、酸性废水排放、富营养化条件下有机物分解等.研究结果为我国地表水锰污染防控、饮用水安全保障与流域水环境综合管理提供科学依据.国家重点研发计划(No.2016YFC0502901);;福建省环保科技计划项目(No.2016R017)~

The existing states and evolution of P and Fe in shallow sediments from the continental slope of northern South China Sea and their indication for the decomposition of gas hydrate

天然气水合物作为当前极具开发潜力的新型清洁能源，受到科学界的广泛关注。海平面下降、洋壳的构造运动、海底沉积物滑塌及洋底水温变化等都可能造成天然气水合物的失稳分解，分解释放的CH4在垂向运移过程中与上层电子受体发生AOM，使SMTZ等作用带磷铁的赋存形态发生变化。磷作为海洋生物的重要营养元素，在海洋生物地球化学循环中有着重要意义，与铁、硫元素及沉积有机质关系紧密，在早期成岩过程中扮演了重要角色；而铁作为地壳中丰度最高的氧化还原敏感性金属元素，在海洋沉积物中的氧化还原过程对磷、硫、碳等生物地球化学重要元素的成岩循环都有重要影响。因此对南海北部陆坡沉积物中磷铁的赋存形态及演化规律的研究，不仅有助我们...Gas hydrates have been receiving extensive attention of the scientific community for their considerable exploration potential. Geological events like eustasy, tectonic movement of ocean crust, seabed sediment collapse and variation of bottom water temperature may cause the decomposition of gas hydrates, the released CH4 in this process reacts with upper electron acceptors(AOM) during upward migrat...学位：理学硕士院系专业：海洋与地球学院_海洋地质学号：2232013115143

Response of carbon and nitrogen geochemical characteristics on the formation and decomposition of gas hydrate in sediments from the northern South China Sea

全球90%的海域分布有天然气水合物，其储量丰富，被认为是21世纪的重要清洁能源；天然气水合物的主要成分为甲烷，其增温潜力是CO2的23倍之多。因此，海底天然气水合物具有重要的能源、经济、环境效应。我国南海具有天然气水合物成藏的有利温度、压力、地质构造等条件，尤其是在南海北部神狐海域和珠江口盆地，广州海洋地质调查局先后于2007年、2013年、2016年钻获水合物实物样品。因而，研究南海北部不同海域天然气水合物潜在区沉积物碳氮地化特征对水合物生成/分解的响应，对我国天然气水合物勘探开发具有重要的现实意义。 本论文依托国家自然科学基金项目《天然气水合物成藏体系中产甲烷与甲烷厌氧氧化作用生物标志物...Marine gas hydrate, as one of the largest methane reservoirs on Earth, is an important subject about the effects of energy, economy and environment. China drilled and obtained gas hydrate samples from the northern South China Sea (SCS) in 2007, 2013 and 2016, suggesting the best prospect area of marine gas hydrate for the northern SCS. Thus, studying carbon and nitrogen geochemical characteristics...学位：理学博士院系专业：海洋与地球学院_海洋地质学号：2232013015379